LESSON 205 / 215·2 min readAdvanced

Stable concepts, framework concepts, and changing APIs

ReferenceReference guide
01 Understand02 Recall03 Prepare

Words made simple

A few useful meanings before you read the explanation.

API
A way for one piece of software to ask another for data or an action. A claims API might return the current status of a claim.
Retrieval
Finding and fetching information that is useful for the current question.
Schema
A description of the fields and value types that data should contain. It helps check that an answer has the expected shape.
More words from this lesson
State
The data describing where a workflow is now, what it already knows, and what still needs to happen.
Idempotency
Making a repeated request have the same intended business effect as one request. It helps avoid duplicate submissions or payments.
Authorization
Checking what that identity is allowed to read or do. Being logged in does not grant access to every record.
Evaluation
Checking results against examples and clear criteria to find whether the system works well and where it fails.
SDK
A set of code tools provided to help an application use a service or framework.
LayerExamplesHow to learn/maintain
Stable engineering conceptsAuthorization, idempotency, provenance, retrieval, evaluation, budgets, state ownershipUnderstand the problem, invariants, failures, and trade-offs
Framework-specific conceptsLangGraph reducers/interrupts, MAF workflows, SDK handoffs, retriever interfacesMap them to stable concepts and test actual behavior
Rapidly changing APIsImports, provider event envelopes, model IDs, supported schemas, cloud branding, pricing, protocol versionsPin compatible versions and consult linked official docs before implementation
PAUSE & RECALL

Can you explain it without the notes?

Stable concepts, framework concepts, and changing APIs

Use your own words. Explain an example and one limitation before checking the explanation.

Check your explanation

Stable concepts, framework concepts, and changing APIs

CONNECT IT TO YOUR INTERVIEW

Turn this concept into a clear answer.

Practice this concept
YOUR NEXT STEP

Keep connecting the ideas.

Next lesson: A concrete architecture proposal template

Adapted from 13_AI.MD · “Stable concepts, framework concepts, and changing APIs”. Examples are study fragments; framework behavior can depend on your version.