Generative AI · A Reader
A guided reader

Generative AI, made clear.

A short, guided read on what generative AI is, how it actually works, and how to use it well at work. Start by picking who you are. The reader shapes itself around you: the chapters on the left, and the further reading inside each one.

How it works: your choice shapes the chapters on the left and the further reading at the end of each one. Change it anytime with the I’m… menu in the top bar, or browse everything. Tap Next or use your arrow keys; it remembers where you left off.
Foundations

New to AI? The four words to know.

In one line: an LLM is a kind of generative AI, which is a kind of machine learning, which is a kind of AI. Each is a smaller circle inside the last.

If terms like "LLM" are still fuzzy, start here. Four words, and how they nest inside each other.

Artificial Intelligence Machine Learning Generative AI LLM chat assistants
Same idea as the takeaway below: each term is a smaller, more specific circle inside the last.
Artificial Intelligence

The umbrella: software that does things we'd call "intelligent", recognizing, deciding, generating.

Machine Learning

The main way modern AI is built: learn patterns from many examples instead of being hand-coded. Your fraud models are ML.

Generative AI

ML that creates new content, text, images, code, rather than only scoring. The wave behind ChatGPT and Claude.

Large Language Model

The kind of generative AI behind chat assistants: a huge model trained on text that predicts the next words.

Foundations

Getting oriented

Three things worth being clear on: what generative AI is, how it differs from ordinary software, and how to work with it well. Each point links to a fuller source.

What it is

Generative AI is software that creates original content, text, images, or code, in response to a prompt, rather than only classifying or scoring data that already exists (IBM).

How it differs from ordinary software

Traditional software follows fixed rules. A generative model instead produces the most probable response, works within a limited context window (its short-term memory), reflects a fixed training cutoff, and can state a wrong answer with full confidence, a failure mode called hallucination. It is capable, but not authoritative (Anthropic, AI Fluency).

How to work with it well

Anthropic frames effective use as four habits: delegate the right tasks to the model, describe them clearly, apply discernment to the output, and exercise diligence in verifying results and handling data. Andrew Ng's Generative AI for Everyone covers the same ground for a non-technical audience: how the technology works, effective prompting, and where it fits (DeepLearning.AI).

References
The types, up close

The family tree

"AI" is one word covering very different things. Most aren't competitors, they're circles inside circles.

An LLM is a kind of generative AI, inside deep learning, inside machine learning, inside AI. Two ideas sit slightly apart: agents are a way of using a model, and neurosymbolic AI is a way of combining a model with logic.

Artificial Intelligence Machine Learning Deep Learning (neural networks) Generative AI LLMs chat assistants live here Agents an LLM in a loop with tools and a goal. A system built on a model, not a new kind of model. Neurosymbolic combines ML (patterns) with symbolic logic, rules, and knowledge graphs. Fluent and rule-bound, so answers are auditable.
Each label sits inside the last. Agents and neurosymbolic AI are the two that aren't just "a smaller circle."
The types, up close · 1 of 6

Traditional ML model

The workhorse behind prediction. It learns patterns from labeled examples and outputs a number or a category.

labeled data ML model fraud? 0.87a score
It turns examples into a prediction, a probability or a class.

Good for: churn, fraud, and credit-risk scoring, anywhere the answer is a number or a class.

The catch: narrow, needs labeled data, and can't write or explain in language. It scores; it doesn't talk.

The types, up close · 2 of 6

Deep learning

Machine learning built from many layers of artificial "neurons." It powers perception, and it's the engine underneath LLMs.

inputhiddenoutput
Layers of simple units, tuned on data, learn to recognize complex patterns.

Good for: image and speech recognition, and the modern models built on top of it.

The catch: data-hungry and hard to interpret, a capable black box.

The types, up close · 3 of 6

Generative AI

Machine learning that creates new content, text, images, or code, rather than only scoring what already exists.

prompt generative model text image </> new content
Give it a prompt; it produces something that didn't exist before.

Good for: drafting, summarizing, and producing first passes.

The catch: it generates the most plausible output, which can be fluent and confidently wrong.

The types, up close · 4 of 6

Large Language Model

The language kind of generative AI: a large model that predicts the next words, one at a time, from the context it's given.

context so far The member couldn't get her loan predicted next word
Everything it does comes from predicting the next word, extraordinarily well.

Good for: the drafting, summarizing, and question-answering behind chat assistants.

The catch: it hallucinates, and it isn't deterministic, the same prompt can vary. The model itself keeps no memory between sessions; assistants like ChatGPT and Claude now add a memory feature on top, a property of the app, not the model.

The types, up close · 5 of 6

Agents

Not a new kind of model, a system. An LLM running in a loop with tools and a goal, taking several steps on its own.

goal Plan Act (tools) Check loop until done done
The model decides the next step, acts, checks, and repeats, without a human between each step.

Good for: multi-step tasks where the path varies and can't be hard-coded.

The catch: it can compound its own mistakes and is harder to control and audit. Earn your way up to it.

The types, up close · 6 of 6

Neurosymbolic

The hybrid the field is moving toward: neural pattern-matching combined with symbolic logic, rules, and knowledge graphs.

Neuralpatterns, fluent + Symbolicrules, graph, exact reasoning you can trust
Fluent language from the neural side; rules and an auditable trail from the symbolic side.

Good for: reasoning across connected records with rules enforced and an answer you can trace.

The catch: newer and harder to build, but it's where trustworthy enterprise reasoning is heading.

Going deeper

Why neurosymbolic works

An LLM is brilliant at language and useless at guarantees. Classic logic is the opposite. Each is strong where the other is weak.

Pure LLMs can't promise they followed a rule, can't show auditable work, and will state a wrong number confidently. Symbolic AI (logic and rules) is rigorous and explainable, but brittle with messy real-world language. Neurosymbolic AI puts them together. A mental model from Daniel Kahneman: the neural side is "System 1" (fast, intuitive), the symbolic side is "System 2" (slow, deliberate). You want both.

Neural · System 1 pattern, perception, fluent & fast + Symbolic · System 2 logic, rules, graphs, auditable & exact both together = fluent and defensible
The neural side reads a member's messy request; the symbolic side enforces the eligibility rule exactly and shows work an examiner can follow.

The symbolic side, in practice: ontologies and knowledge graphs

Its most popular modern form is concrete, and increasingly the phrasing you'll hear. An ontology is a shared, formal definition of what things are and how they relate (one meaning for "member," "delinquent"). A knowledge graph stores information as entities and explicit relationships (a member owns an account, which is collateral for a loan). Together they're the symbolic half of neurosymbolic.

In plain termsWhen someone says "we need a knowledge graph" or "an ontology layer," they're describing the symbolic half of neurosymbolic AI: the governed structure that lets a fluent model reason in a way you can trust and defend. (Same idea as GraphRAG, later.)

Beyond RAG: modeling meaning, not just retrieving text

Basic RAG retrieves passages of text that look relevant. The step past it is to model the meaning: define your terms once (semantics), and store how things relate (a knowledge graph), so a system can reason across connected facts and show the path it took. The harness is the operational side of the same move, the layer that runs this with memory, tools, and governance instead of a fresh, forgetful chat each time. You don't have to build any of it to see the point: it's why "get the data modeled" tends to beat "buy a smarter model."

Further reading
Going deeper

Watch these (~10 min each)

Four short, durable explainers. Tap a card to watch. The two channels that have aged best for clear, non-technical AI teaching.

Cards open on YouTube in a new tab.

The core idea

What GenAI is, in 90 seconds

Read this first. It's the idea everything else builds on.

A generative AI model is like a very well-read new hire on their first day. It has read an enormous amount and writes fluently on almost anything. But it has no memory of your organization, no access to your systems, and it will answer confidently even when it's wrong. A capable mind with no context and no hands.

Everything useful comes from what you add around it: what you tell it (instructions), what you give it to read (your documents), and what you let it do (tools). The model is the engine. The value is the car you build around it.

The model reads all, knows nothing of you Your instructionswhat you tell it Your documentswhat it reads Tools & actionswhat it can do
On its own, a fluent generalist with no context. Instructions, documents, and tools make it useful.
The core idea

A power tool for expertise, not a replacement

The bottom line: used well, AI takes the busywork off your plate so you can spend more time on judgment, relationships, and the calls only a person should make. It's a skill to learn, not a threat to fear.

Before we go further, the honest version: AI is very good at the mechanical parts of knowledge work, and genuinely bad at the parts that are actually your job.

It drafts, summarizes, searches, and takes first passes tirelessly. It does not know your members, carry your judgment, or hold accountability for a decision. Those stay with you, and in a regulated institution, they have to.

What AI is great at

Drafting and rewriting, summarizing long documents, searching across files, first passes, repetitive formatting, explaining jargon.

What stays human

Judgment, accountability, member relationships, domain context, reading the room, and the final decision.

We've done this before: the word processor, the spreadsheet

Every generation of knowledge work got a new power tool. The word processor didn't replace writers; it freed them from retyping. The spreadsheet didn't replace accountants; it took over the arithmetic and made their judgment the valuable part. The calculator, email, the search engine, each removed drudgery and raised the value of the thinking on top. Generative AI is the newest tool in that line. It changes the mix of your work; it doesn't erase the reason you're in the seat.

The pattern that wins is consistent: the expert who uses the tool well outperforms both the expert who ignores it and the tool used alone. AI automates tasks, not roles.

The current state, no hype

What AI is actually good at today

The honest framing: these are task-specific skills, not general intelligence. Several (OCR, transcription, sentiment) are mature, well-understood capabilities that AI has simply made easy and cheap to use. That's exactly why they're reliable.

Skip the science fiction. Here's the concrete, unglamorous list of what today's AI does reliably, as long as you give it the input to work from.

Summarize

Condense long documents, call notes, and email threads. A 40-page policy into five bullets a teller can follow.

Draft & rewrite

Member letters, emails, and plain-language explanations. Turn dense jargon into something a member understands.

Classify & route

Sentiment, intent, topic, priority. Read the tone of a complaint, or triage inbound messages to the right team.

Extract

Pull names, dates, amounts, and clauses out of messy forms and contracts into clean fields.

Read & transcribe

OCR: turn scanned forms and PDFs into text and data. Speech-to-text: turn calls and meetings into transcripts.

Answer from your docs

Grounded Q&A and semantic search: find and answer from your actual policies by meaning, not just keywords.

Also dependable, with a human reviewing: writing and checking code and spreadsheet formulas, drafting data cleanups, and brainstorming outlines, checklists, and options.

The current state, no hype

Where it still needs a human

The reliable pattern: let AI do the language-heavy first pass, then a human verifies and owns the outcome. Fast where it's strong, checked where it's not.

The other half of no-hype: the tasks today's AI is unreliable at, or shouldn't do alone. Knowing these keeps you out of trouble.

Don't rely on it for…WhyDo this instead
Exact math & totalsit predicts text, it doesn't calculategive it a calculator/tool, or check the number
Facts without a sourceit can invent confident, wrong answersground it in your documents
Current / real-time infoits training has a cutoff dateuse tools that retrieve live data
Guaranteeing a rule or compliance outcomeit offers no hard guaranteesenforce with rules and a human sign-off
Reasoning across all your messy datastill the frontier (neurosymbolic)knowledge graphs + human oversight
A final, accountable decisionaccountability is a human thingkeep a person on the call
The current state, no hype

How people actually use it today

Same engine, different surface: a chat box for quick help, cowork for real deliverables, an editor for code, a framework for automation you own. Pick the surface that fits the job, and the person.

The same model shows up in very different places. These are the main ways people work with AI now, from a chat box to your desktop to a developer's editor.

In a chat window

Claude, ChatGPT, Gemini. Ask, draft, summarize, rewrite. The front door for everyone, no setup.

Working across your files ("cowork")

Claude on the desktop. It reads a folder, writes documents, runs analysis, and uses Skills (saved playbooks) and connectors (Slack, Notion). It does the work, not just talk about it. This guide was built this way.

Inside the tools you already use

Copilots in Microsoft 365, Google Workspace, and your CRM. AI shows up where you already work.

In a developer's editor or terminal

Cursor (an AI-native editor), Claude Code (agentic coding in the terminal), GitHub Copilot. For people who write code; the AI writes, edits, and runs it.

Custom agents you build

LangChain / LangGraph and the Claude Agent SDK, wired to your systems over MCP. For teams building their own automations on top of a model.

See the tools
Choose your focus

Pick your focus

The concepts don't change. What changes is the question you're trying to answer. Jump to yours, or read all three.

Focus 1 · Domain Expert

You're the expert. This is your assistant.

The mindset: it takes the busywork (retyping, hunting through files, first drafts). The judgment, the relationship, and the final call stay with you, and become the more valuable part of your day.

Think of AI as a sharp, tireless assistant who drafts and fetches, while you stay the one who checks and decides.

You've spent years learning how lending, compliance, operations, or member service actually work. None of that is being handed away. The goal of this focus is narrow and practical: make the expertise you already have go further, and faster, by letting a capable assistant handle the parts that don't need you.

You don't need to be technical. You need a clear picture of what the tool is good and bad at, the kinds of work you can hand it, and how to tell when it's genuinely helping. That's the whole focus.

Here's the path we'll walk

  1. Four concepts, simply. What the tool actually is, so it stops feeling like magic.
  2. Three kinds of work. Chat, coworking across your documents, and code, from easiest to most powerful.
  3. The moving parts. What's happening under the hood, and what to keep an eye on.
  4. What "success" looks like, so you know when it's working and when to stop and check.
Focus 1 · Domain Expert

Four concepts, explained simply

You don't need to know how an engine is built to drive well. You do need these four ideas.

1. A very well-read intern, not a search engine

It generates the most likely next words from what it read in training. It's not looking up a fact. That's why it's brilliant at drafting and can also be confidently wrong. Think "smart intern who read everything," not "Google."

2. Its memory is a desk, not a filing cabinet

It can only "see" a limited amount at once (the context window). Like a desk: only so much fits, and it's cleared each session. Newer assistants can carry saved notes between sessions (a memory feature of the app, not the model), but the desk itself still empties, which is why giving it the right document matters. You're loading the desk.

The context window = the desk only so much fits at once, and it's cleared each new session your prompt a policy the chat so far
Give it the right things to work from, the relevant policy, the account note, the prior email. Anything not on the desk is invisible to the model.

3. It will guess, so you verify

Because it produces the most plausible answer, it will sometimes invent a citation or a number with total confidence. This is hallucination, and it's a property of the technology, not a switch you can flip (IBM explains why). Treat every answer as a draft to check.

4. Ground it, and it stops guessing

The fix is grounding: give it the real source and ask it to answer from that. Now the answer is specific, current, and traceable to a document you can point to.

And one rule before any of it: use the tools your institution has approved, and keep member data out of anything it hasn't. A personal ChatGPT or Claude account is not an approved place for member PII.
Check yourself: the AI gives a confident answer on a member's eligibility. What do you do?
Verify against the actual policy or record before acting. If it grounded the answer in a document, check that document. Confidence is not correctness.
Focus 1 · Domain Expert

Writing a good prompt

The single most useful skill, and the one this track keeps pointing back to. A strong prompt usually has four parts.

PartWhat it doesExample
Rolewho it should act as"You are a compliance analyst."
Contextthe material and the situation"Here is our overdraft policy: [paste]."
Taskwhat to produce"Summarize it in five bullets a new teller can follow."
Formatlength, structure, audience"Plain language; flag anything about ID verification."

When you can, add one example of a good answer. Showing beats describing.

Same task, weak vs. strong

Weak

"Summarize this policy." No role, no audience, no format, so you get a generic summary you still have to rework.

Strong

"You are a compliance analyst. Summarize this overdraft policy in five bullets a new teller can follow, in plain language, and flag anything about identity verification." Usable on the first try.

The habitSpend the extra fifteen seconds on role, context, task, and format. It's the cheapest way to get a better answer, and it works on any tool and any model.
Check yourself: you need a member letter explaining a fee reversal. What makes the prompt strong?
Give it a role ("you are a member-services rep"), the context (the account note and the fee being reversed), the task (draft the letter), and the format (warm, plain language, under 150 words). Then verify the facts before it goes out.
Go deeper · prompting
Focus 1 · Domain Expert

Three kinds of work: chat → docs → code

As you get comfortable, the work climbs a ladder. Each rung gives the AI more to work with, and asks for more care.

1 · Chatask, draft, summarize 2 · Cowork on docscompare, extract, synthesize 3 · Code & actionsruns code, uses tools
Most people live happily on rungs 1 and 2. Rung 3 is powerful and where "check the work" becomes non-negotiable.

Rung 1, Chat. You type, it answers. Draft a letter, summarize a call note, rewrite in plainer language. Fast, low-risk, best place to build fluency.

Rung 2, Cowork across documents. You bring your material, policies, a contract, notes, and work over it: "compare these disclosures and list what changed." The biggest day-to-day lift. Under the hood this is retrieval-augmented generation (RAG) (IBM explainer).

Retrieval-augmented generation: a question retrieves relevant passages, which the model uses to answer
"Cowork across documents": the tool retrieves the passages relevant to your question and hands them to the model, so the answer comes from your material, not the model's memory. Diagram: "RAG schema," Wikimedia Commons, CC BY-SA 4.0.

Rung 3, Code & actions. It writes and runs code or uses tools to take steps: crunch a spreadsheet, pull from a system, file a ticket. You describe the outcome; it does the mechanical work. This is where real automation lives, and where oversight matters most.

Focus 1 · Domain Expert

The moving parts

What's constant: two parts are always on, your instructions and your verification. The AI's quality is bracketed by a human at both ends, at every rung.

Every AI interaction is the same handful of parts. Climbing the ladder just switches on more of them.

PartChatDocsCode
Your instructionsononon
The modelononon
Your documentsonon
Tools & actionson
Memory (across sessions)optoptoften
Your verificationononon
Focus 1 · Domain Expert

So what does "AI success" mean?

Most people get this backwards. Success isn't a smarter model. It's the right context, grounded in the right data, with a human verifying.

Clear inputgood instructions Groundingthe right data Modeldrafts an answer Human checkverify, then trust what you learn feeds better inputs next time
A good outcome is a loop, not a magic answer. Weak input or missing grounding produces confident nonsense.
In shortSuccess is mostly about what you feed it and how you check it, not which model you use. Good habits on a basic tool beat sloppy habits on the fanciest one.
Go deeper · for domain experts
Focus 2 · The Builder

Creating value with AI, safely

Your question: where do we invest, what do we build, and how do we keep it governed? Four ideas carry most of the weight.

1. The model is the engine, not the car

Standardize on one model now, but keep the freedom to swap. That comes from design: put prompts, memory, grounding, tools, and rules in a layer above the model (the harness), and connect through the open MCP standard. Then "change the model" is a config change, not a rebuild.

The harness you build prompts · memory · tools · rules · governance · logging Model Claude today, something else tomorrow
Keep prompts, memory, tools, and rules in the harness. Then the model in the middle is a swap, not a rebuild.

2. Workflows before agents

A workflow follows steps you designed; an agent decides its own. Workflows are predictable, cheap, auditable. Use the simplest thing that works, keep humans in the loop for member-facing work, and earn your way up to autonomy.

3. The data foundation is the real bet

Basic "chat with your documents" disappoints on the questions that connect facts across systems. The durable advantage is a governed, relationship-aware view of your data, consistent definitions and the relationships between accounts, products, and interactions. The model keeps changing; clean, connected data compounds.

4. Governance is the price of admission

The NCUA has no separate AI rulebook: it examines AI through the frameworks you already answer to, safety and soundness, vendor risk, fair lending, BSA/AML. Audit trails, validation history, version control, and board-level ownership are how you show your work under those frameworks. Build observability and guardrails in from day one; you can't bolt an audit trail onto a system that wasn't built for one.

A sensible sequenceLiteracy → low-risk workflows (human-in-loop) → the data-foundation work in parallel → harness & governance early → agents only where the path varies. Most institutions skip to the end and stall.
Check yourself: a demo answers your document questions flawlessly. What's the one question to ask?
"What is it running on?" Demos run on clean, curated data. The real test is your systems, with your inconsistent definitions and governance needs. Ask to see it on a messy, cross-system question.
Go deeper · for builders
Focus 2 · The Builder

The data foundation is the moat

The bet: model the meaning once. Every system, every agent, and every examiner-facing answer inherits it. Slower to start, far cheaper to live with.

The unglamorous work that decides whether AI holds up: defining what your data means, once, so every system and every agent can reuse it. It rarely ships a feature this sprint, which is exactly why it gets skipped.

Define it once, or define it eight times

Without shared definitions, every team, and every AI use case, ends up defining "member," "active," and "delinquent" a little differently. Do the semantic work once, as agreed definitions and a knowledge graph of how things relate, and every consumer, agents included, plugs into the same foundation instead of building its own version of reality.

DEFINE ONCE Governed definitions + knowledge graph REUSED BY EVERY CONSUMER Dashboards ML models AI agents Reports & exams
Define "member," "active," and "delinquent" once. Dashboards, models, agents, and examiner-facing reports all read the same governed meaning.
What Gartner foundBy 2027, Gartner projects that organizations that prioritize semantics in their AI-ready data will increase agentic AI accuracy by up to 80% and cut costs by up to 60%. The point is blunt: the accuracy gap isn't closed by a bigger model. It's closed by defined meaning.

Semantic debt

Skipping the definitions is like technical debt, except it doesn't appear on any roadmap. It surfaces later, when a second team tries to reuse what you built, or when an agent gets a question nobody anticipated and has no structure to reason with. Data quality then becomes a cleanup project instead of something built in.

The moatWe call our knowledge a moat, then operationalize it as flat tables and embeddings. Flat data is easy to copy. Structured, validated knowledge, how your concepts relate and constrain each other, is not. Strip it down and you've handed a competitor's agent the same starting line.

Someone has to own it

Because it cuts across every team, the semantic layer easily becomes a shared responsibility that belongs to no one. It needs a clear, accountable owner for that roadmap, not a backlog nice-to-have that each team quietly reinvents in its own corner.

Go deeper
Focus 2 · The Builder

Where AI projects fail

The model is almost never the reason. Projects stall one rung below: on data nobody connected, meaning nobody modeled, and decisions nobody owned.

The 2025 numbers were blunt. MIT's Project NANDA found 95% of enterprise GenAI pilots showed no measurable P&L return. S&P Global found 42% of companies abandoned most of their AI initiatives, up from 17% a year earlier. Gartner predicts 60% of AI projects that lack AI-ready data will be abandoned through 2026. Different studies, same diagnosis: these are foundation failures, not model failures.

The four rungs, and how each one fails

1. Retrieve

A chat interface on a raw model answers from training memory: fluent, confident, and ungrounded. Retrieval (RAG) fixes the worst of it by handing the model your documents. But retrieval alone stops at "find text that looks similar." It cannot connect facts across systems.

2. Link

The systems get connected, the data flows, the demo works. This is where most stacks stop, and where the subtle failures start: linked is not modeled. Each source still defines "member," "active," and "delinquent" a little differently, so a cross-system question comes back wrong, with citations. The pipes carry data; they carry no meaning.

3. Model

Shared meaning: definitions agreed once (an ontology) and relationships stored explicitly (a knowledge graph). This is the rung that gives agents and reasoning engines something real to reason over, and it is the rung the failed-pilot statistics point at. Skip it and every use case re-invents its own version of reality; build it without an owner and it quietly drifts.

4. Decide

The point of the whole stack: a decision a person makes and the institution owns, with lineage an examiner can follow. No tool occupies this rung. If a pilot produces insight but changes no decision anyone is accountable for, it demos well and changes nothing.

The landscape, honestly

Each layer below is real, useful, and routinely oversold as the whole answer. The right question for any tool is which rung it stands on, and what it still needs above it.

LayerWhat it doesWhat it can't do alone
Data catalog
Collibra, Atlan
Describes what data means and where it livesA glossary describes; it doesn't answer questions or make calls
Pipelines & fabric
Fivetran, streaming fabrics
Move and link data across systemsLinked is not modeled; a connection carries no meaning
Semantic layer & knowledge graph
dbt, Neo4j, GraphDB
Model what things mean and how they relateA model nobody governs drifts, and meaning is still not a decision
Reasoning engine
Prometheux, Stardog
Infers new facts by applying rules over the graphInference is only as good as the modeled meaning beneath it
Agent harness
Claude Agent SDK, LangGraph, LlamaIndex
Runs the loop: tools, memory, guardrailsOn ungrounded data it automates guesswork, faster
Evals & observability
LangSmith, Arize, your own eval set
Prove behavior and catch driftMeasurement can't supply meaning
DataOS
The Modern Data Company
The operating system across the rungs: grounds in your catalog, models meaning as governed, ontology-registered data products, and runs agents and inference partners on topThe decision stays human; DataOS exists so the person making it works from governed meaning, and the call is owned, auditable, and compounds
The decision seatEvery layer on this list exists so that a person can make a governed call the institution owns, and defend it later. That seat is what DataOS is built around, and a disclosure is owed: this reader comes from the DataOS team, so weigh that row accordingly. The rung logic stands on its own. Vendors sell bottom-up; design top-down, from the decision that has to get better back to the meaning, the links, and the retrieval it needs.
Check yourself: a vendor demo answers cross-system questions perfectly. Which rung is it standing on?
Ask whether the definitions were modeled, or hand-curated for the demo. If "member" means three different things across your systems, the demo skipped rung 3, and production will find that out for you.
Focus 2 · The Builder

The model zoo: which model, and whose?

How to choose: you don't pick one and marry it. You match the model to the job, and the model-agnostic harness (the engine, not the car) lets you route each task to the right model and swap them as they improve.

"AI model" isn't one thing. Models come in different sizes and shapes, and you can rent them or run your own. Matching the model to the task is where a lot of cost, speed, and privacy is won or lost.

By size and shape

LLM · Large Language Model

The big generalist. Best at hard reasoning, drafting, and open-ended Q&A. Most capable, most expensive per use. Your default for complex language work.

Reasoning model

A frontier model that "thinks" in steps before answering (GPT-5 thinking, Claude with extended thinking, Gemini thinking). Markedly better where a wrong intermediate step ruins the answer; slower and much pricier per call. The classic cost mistake is routing everything through one.

SLM · Small Language Model

Compact and fast (millions to a few billion parameters). Great for narrow, high-volume jobs: classify, extract, route. Cheap, low-latency, and can run privately or even on a laptop or branch server. Examples: Phi, Gemma, Ministral.

VLM · Vision-Language Model

Understands images and text together. For reading documents, IDs, checks, screenshots, and charts. The engine behind smart document processing. Frontier models read images natively; a dedicated VLM matters when you run your own.

Embedding model

The quiet workhorse. Turns text into vectors so you can search by meaning. Small and cheap; it's what powers "answer from your documents" (RAG).

By ownership: rent the frontier, or run your own

Hosted frontier

Anthropic, OpenAI, Google. The most capable models, easiest to start, pay-per-use API. Data leaves your perimeter (mitigated by enterprise no-training terms). Fast to adopt; cost scales with usage; some vendor dependency.

Local / open-weight

gpt-oss, Qwen, Llama, Mistral, Gemma, Phi. Run in your own cloud/VPC, on-prem, or at the edge. Data stays in your control; fixed infrastructure cost, no per-token fee. You own the operations, and the best open models still trail the frontier on the hardest tasks.

Reading the leaderboards

Three kinds of scoreboard, measuring three different things. Arena ranks models by blind, head-to-head human preference votes. Artificial Analysis charts measured quality against speed and price, hosted and open-weight side by side. LiveBench refreshes its questions monthly so models can't have memorized the answers, and SWE-bench tests whether a model can resolve real GitHub issues end to end. Links below.

Directional, not decisiveVendors tune for the public benchmarks, scores compress at the top, and none of these tests ran on your data. Use the leaderboards to shortlist two or three candidates, then decide with a small eval set built from your own tasks. The leaderboard that matters is yours.
Focus 2 · The Builder

Inference, edge, and choosing per task

Two words you'll keep hearing, then a simple guide to which model to reach for.

Inference

Running a trained model to get an answer, as opposed to training it in the first place. This is where your ongoing cost and speed live: every request is an inference, and volume times model size drives both the bill and the latency. Bigger model = smarter but slower and pricier per call.

Edge AI

Running a model close to where the data is, on a branch server, a laptop, a kiosk, instead of sending it to a data center. Small models (SLMs and VLMs) make this practical. The wins: privacy (data never leaves the device), low latency (no round trip), and it works offline.

When to reach for what

The jobReach for
Hard reasoning, drafting, member Q&A over policyHosted frontier LLM (Claude / GPT / Gemini)
High-volume classify / extract / route, cost- or latency-sensitiveSLM (often self-hosted)
Reading documents, IDs, checks (images)VLM
Sensitive data that can't leave, or offline / branch useLocal open-weight model in your VPC or on-device
Search over your own documents (RAG)Embedding model + an LLM
In practiceData handling is the gate. Hosted providers offer enterprise no-training terms; local models keep regulated and PII data inside your perimeter. Route the sensitive, high-volume work to small/local models and the hard reasoning to the frontier, and let the harness swap models as they get better and cheaper.
Go deeper · models & deployment
Focus 2 · The Builder

Harnesses at the edge

If you're going to run AI on your own turf, for privacy, latency, or examiner comfort, the durable design is a layered stack where the data stays inside your perimeter and every layer is swappable.

The core question for a credit union isn't "which model is smartest." It's "where does the data go, and can I prove it never left." Every choice below flows from that one constraint. Treat the layers as durable and the specific tools as replaceable.

Your perimeter · VPC / on-prem / branch Gatewayroute · enforce policy · log every call Guardrailsredact PII on the way in · filter on the way out Harnessmemory · MCP tools · human-in-the-loop Local small model + in-perimeter RAGyour embedding model + your vector database Frontier model(cloud) escalate only under policy Everything logged. Nothing sensitive leaves without an approved, logged reason.
Five layers, all in-perimeter: a gateway, guardrails, the harness, and a local model with your own retrieval. The model is just a service the harness calls, so you can swap it.

The three durable rules

Small-model-first, with a policy gate. A cheap local model handles the bulk of the work; only genuinely hard reasoning escalates to a frontier model, and the gateway is where you enforce which classes of data may never cross that line.

Prototype simple, ship for load. Running a model on a single box is fine to prototype. Anything member-facing needs a production inference server that handles many requests at once.

Log at the gateway and the harness. That log, every prompt, response, and tool action, is your audit trail. In a regulated shop it's not optional, and it's far easier to build in than to add later.

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Focus 2 · The Builder

The edge toolkit

The real, current tools for each layer. The names will change; the layers won't. This is a map, not a mandate.

Serving (run the model)

Ollama / LM Studio for prototyping and single-user tools; vLLM / SGLang for production load; NVIDIA NIM for a vendor-supported, air-gap-capable box. (llama.cpp / GGUF runs underneath.)

Gateway / router

LiteLLM is the common self-hosted, OpenAI-compatible gateway: routing, failover, budgets, virtual keys, and central logging in one choke point.

Guardrails

NeMo Guardrails, Guardrails AI, and Llama Guard: redact PII on the way in, classify and filter on the way out, log both.

Vector DB (self-hosted RAG)

pgvector if you already run Postgres; Qdrant if you don't; Milvus/Weaviate for large scale; Chroma for prototyping. Retrieval stays in-perimeter.

Orchestration/harness frameworks that tie it together: the Claude Agent SDK, LangChain, and LlamaIndex, with tools exposed over MCP.

Mistakes to avoidOllama isn't production, use vLLM for real load. Don't start new work on Hugging Face TGI (it's in maintenance mode). "Local" alone isn't "compliant", you still need the logging, guardrails, and audit trail. And don't over-engineer the router: start with simple tier-based routing and failover before reaching for semantic routing.
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Focus 2 · The Builder

Open-source models for banking

In 2026 you can build a credible on-prem stack without ever calling a frontier API. For a regulated buyer, the license and the deployment story usually matter more than the last benchmark point.

IBM Granite (Apache 2.0)

The most deliberately enterprise/finance-positioned open family, trained on curated business data with a finance domain, and paired with safety and governance tooling. Best for "open, but with an accountable vendor and a lineage story."

Llama (custom license)

Llama 3.x 8B/70B is still the installed-base workhorse with the biggest fine-tuning ecosystem; Llama 4 is the current, natively multimodal generation. License is permissive-but-not-Apache, so have counsel confirm terms.

Mistral / Qwen / Phi / Gemma

Mistral and Qwen (Apache 2.0) are clean, efficient choices; Qwen's vision variants are excellent at documents. Phi (MIT) is tiny and cheap for extraction. Gemma is capable under a custom Google license. OpenAI's gpt-oss (Apache 2.0, 20B/120B) is a mainstream on-prem option, the 120B runs on a single 80GB GPU. DeepSeek (MIT) is highly capable, but its Chinese origin draws US regulatory scrutiny; most US regulated institutions pass.

FinGPT (open framework)

Not a single model but finance-specific data pipelines and LoRA recipes on open bases, a useful reference for sentiment, extraction, and instruction tuning. BloombergGPT is not open, don't plan a build around it.

License checkApache 2.0 (Granite, Mistral, Qwen) and MIT (Phi) are clean. Llama and Gemma carry custom terms your counsel should clear before production. This is a legal gate, not a technical one.

The expensive mistake: fine-tuning to teach facts

Fine-tuning changes a model's behavior, its output format, vocabulary, and tone. It does not reliably store facts, and the model tends to forget what it knew. So don't fine-tune to inject your policies. Put changing facts in RAG, where they're grounded, current, and citable, and where your data stays on-prem.

Reach for LoRA / QLoRA when you need a consistent output format at scale (say, structured credit-memo JSON) or a house voice that prompting can't hold. QLoRA tunes an 8B–70B model on modest local GPUs, and tuning locally is itself a privacy control. The 2026 sweet spot: a QLoRA-tuned open model with RAG on top; a few thousand good examples plus retrieval captures most of the value.

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Focus 2 · The Builder

Banking workflows, and the governance around them

The point of all this is the work. Here's the use-case catalog with the model and pattern for each, and the governance that keeps it examiner-ready.

Use caseModel + patternHuman?
KYC / document extraction (IDs, statements)Local VLM · IDP extractionreview exceptions
KYC/AML + adverse-media screeningLocal SLM · RAG + agentyes (SAR calls)
Fraud / dispute narrativeLocal SLM · summarize (detection = ML)yes
Credit memo / underwriting narrativeFine-tuned SLM + RAGhuman decides
Adverse-action reason phrasingLocal SLM · phrases an explainable modelyes
Member service / agent-assistLocal SLM · RAG + next-best-actionrep in loop
Compliance & policy Q&ALocal SLM · RAG with citationsoptional
Call summarizationLocal SLM · summarizelight review

Rule of thumb: default to a local small model; escalate to a frontier model only for open-ended reasoning or messy multi-document synthesis. Every consequential decision keeps a human committer.

Governance you can't skip

Model risk. In April 2026 the Fed, OCC, and FDIC replaced the long-standing SR 11-7 guidance with a more principles-based standard (Fed SR 26-2 / OCC Bulletin 2026-13). Written for the largest banks and not adopted by the NCUA, it is still the framework examiners reach for. It treats generative and agentic AI as "novel and rapidly evolving" and out of formal scope, but supervisors and internal audit apply model-risk discipline to LLM systems by analogy. The prudent posture: treat your AI systems as governed models, with validation, monitoring, version pinning, and a decision record.

NCUA. No separate AI rulebook. It maps AI onto existing frameworks, safety and soundness, third-party/vendor risk, and fair lending, and its 2026 priorities center on credit risk, fraud, and BSA/AML. A board-approved AI policy and a retrievable decision record for any AI touching lending, BSA/AML, or member routing are the prudent posture, one examiners will recognize even though no rule names it.

The fair-lending tripwireECOA / Regulation B requires specific reasons for a denial. An LLM must never be the reason-generator for a credit decision. Use it only to phrase reasons that come from an explainable underlying model. "The algorithm said no" is not a compliant adverse-action reason, and the CFPB has said so.
The other side: AI used against youThe same technology powers fraud. Three seconds of audio is enough for a convincing voice clone, and deepfake KYC and executive-impersonation scams are now a top financial-sector risk. The defenses are procedural, not technical: call-back verification on known numbers, code words for wires and account changes, and never acting on a voice alone. FS-ISAC's deepfake guidance is the standard reference.

Texas note. TRAIGA, the state AI law effective January 2026, mainly regulates government use of AI and bans intentionally discriminatory AI; a federally insured institution following existing banking law is largely carved out. Know it exists, don't build your program around it.

Why on-prem open models help hereRunning open weights on your own infrastructure keeps member PII inside your perimeter, gives you full auditability and lineage, and lets you pin model versions for reproducible validation, exactly what model-risk and vendor-risk expectations reward.
Go deeper · governance & finance
Focus 3 · The Analyst

Accelerating the work, honestly

The frame: AI speeds up the work around the model. It doesn't replace the model, and it doesn't replace your judgment about the data.

The first thing to be clear about: generative AI changes the work around your model, not the model itself.

Take churn. A gradient-boosted or survival model on good features still beats asking an LLM "who's going to churn." What LLMs change is the surrounding work: exploratory analysis, drafting and documenting feature engineering, generating and reviewing code, explaining output for a business audience, turning a vague request into a testable spec. Treat the model as a fast, occasionally wrong analyst beside you, not the algorithm.

Two pages follow: where AI actually fits in your pipeline, and the one thing that quietly decides whether any of it works.

Focus 3 · The Analyst

Where it fits in your pipeline

A data-science project is a pipeline. AI speeds up specific stations, and you verify at each one.

Data Explore Features Model Evaluate Explain Teal = where AI speeds you up. You own the result at every station.
The model is one station of six. AI helps most with the language-and-code-heavy ones, exploring, building features, and explaining.
Exploration & EDA

Profiling a table, proposing hypotheses, drafting the first pass of a notebook.

Code, written & reviewed

Generating transformations, and reviewing yours for bugs and edge cases.

Explanation

Turning model output into plain language for a business owner, caveats intact.

Agentic analysis

Letting an agent iterate on a query, with evals and a human check on the conclusions.

Where you let an agent iterate, keep evals and a human check on the conclusions, not just the code. Fast and wrong is still wrong.

Check yourself: AI writes a whole transformation in seconds. What comes next?
Read it like a code review: check the joins, the edge cases, and whether the logic matches what you asked for. Generated code is still code you own and sign off on.
Focus 3 · The Analyst

The data still decides it

The one thing: reconcile the definitions and the modeling is the easy part. Skip it and inconsistent features quietly break the project.

The thing that decides success has nothing to do with which LLM you pick. It's the data.

Churn is a relationship problem: risk lives in the connections across accounts, products, transactions, channels, and service history, and each source defines "member" and "active" a little differently. Reconcile those definitions and the modeling is easy. Skip it and inconsistent features break the project quietly, especially when a feature is computed one way in training and another way in production.

Across all three focus areasThe same governed, relationship-aware data foundation that makes AI answers trustworthy (domain expert) and auditable (builder) is what keeps your features consistent from training to production. One investment, three returns.

This is your stake in the Builder's semantic layer. The same governed definitions that make an agent's answer defensible to an examiner are the ones that keep "active member" computed the same way everywhere your features are built.

Check yourself: an LLM writes a clean churn feature in seconds. What's the risk?
That its definition doesn't match how the concept is computed in production or elsewhere. Fast code on an inconsistent definition ships a silent error. Verify the definition against your governed source.
Go deeper · for analysts
The Library

The library

The explainers, lectures, courses, and papers behind every concept in this reader, organized so you can go as deep as you want on any of them.

Reading the tags: Essential marks the one read to do for each concept. Start here needs no background. Comfortable assumes some hands-on time with ChatGPT or Claude. Deeper is for when a topic hooks you. Everything is free unless marked.
Wrap-up

One foundation, three focus areas

The domain expert learns to use it well. The builder learns to deploy it safely. The analyst learns to accelerate honestly. All three depend on the same thing.

The model at the center keeps changing, and it will keep getting better. What compounds underneath every focus is the same: clear inputs, grounding in trustworthy data, and a human accountable for the result. Get those right and the technology serves the work. Get them wrong and no model will save you.

That's the whole picture, at every altitude. Revisit any page from Contents, and share this reader with anyone who's getting started.