Reference architectures for AI apps, and when each one fits.
Six shapes most production AI systems take, what each is made of and how it fails first. Each one links the lab that builds it.
Read the six patternsEach pattern names who decides the next step.
Look inside
Each opens to when to use it, its parts, how it fails first and the lab.
1Workflow with one model step
Your code decides.
Open the details
- When to use it
- The steps are known in advance and only one needs judgement: triage, extraction, drafting for approval.
- Its parts
- A queue or trigger, Deterministic steps, One model call with a schema for its output, An exception path to a human.
- How it fails first
- The model step returns something the next step cannot parse. Validate its output against a schema and route failures to a human.
- The lab
- Agentic AI System Design for Engineers & PMs
2Single agent with tools
The model decides.
Open the details
- When to use it
- The path depends on what the agent finds: research, debugging, open-ended support.
- Its parts
- A model in a loop, A small set of well-described tools, A step limit and a budget, Traces for every run.
- How it fails first
- It loops or wanders. Cap steps and spend, and read traces of failed runs every week.
- The lab
- Build a Mission Control for AI Agents
3Supervisor with workers
A supervisor model decides.
Open the details
- When to use it
- The work splits into parts that need different tools, permissions or can run in parallel.
- Its parts
- A supervisor that plans and routes, Workers with narrow tools, A written contract for what each worker returns.
- How it fails first
- Context is lost at handoffs. Define what each worker returns, and test the handoff, not only the worker.
- The lab
- Build a Multi-Agent System with MCP
4Retrieval over your documents
Your code, then the model.
Open the details
- When to use it
- Answers must come from your own documents and cite them.
- Its parts
- Parsing that keeps structure, Chunking and embeddings, A vector index with filters, Answer generation with citations.
- How it fails first
- The right chunk is never retrieved. Measure recall on real questions before tuning the prompt.
- The lab
- Build a Second Brain with Claude Code
5Durable agent with human approval
The model, inside a workflow engine.
Open the details
- When to use it
- Runs take minutes to days, call slow systems or need sign-off.
- Its parts
- A durable workflow engine, Tool calls as retryable steps, Approval steps that can wait, Idempotent side effects.
- How it fails first
- A retry repeats a side effect, such as sending an email twice. Make every side effect idempotent.
- The lab
- Agentic AI System Design for Engineers & PMs
6Tools behind a gateway
Policy at the gateway decides.
Open the details
- When to use it
- Several teams and agents share tools through MCP.
- Its parts
- MCP servers per system, One gateway in front, Access rules per team and agent, An audit log of calls.
- How it fails first
- An agent can call a tool nobody meant it to. Default to deny and log every call.
- The lab
- Secure AI Agents with Guardrails
What each pattern gives you
When to use it.
The job shape that fits it.
Its parts.
What you build and run.
How it fails first.
The break you will see before any other.
The lab that builds it.
A recording or an upcoming Live Lab.
Build one of the six live on Thursday
Save a free seatRather read first?
The Top 1% Engineers newsletter sends one production lesson per issue.
We email you each new issue. You can leave at any time. Privacy