A7Advanced 75 minutes reading and codeLocked

Stateful Graph Orchestration — Durable Execution and Checkpoints

Agent is a state machine; nodes are functions; edges are transitions; state is checkpointed after each node. Resume from any failure at the last successful checkpoint. LangGraph is the 2026 reference for this model of low-level stateful orchestration.

In this lesson

  1. 01Learning Objectives
  2. 02The Problem
  3. 03The Concept
  4. 04Build it
  5. 05Use it
  6. 06Exercises
  7. 07Key Terms
  8. 08Further Reading

About 1000 words of reading, with code, 7 quiz questions and the tutor.

The full lesson opens with an access code

You can see what this lesson covers and the milestone it sets. The full text, code, quizzes, the tutor and the AI reviews come with the K850 practice, along with weekly build sessions and code review.

Codes come with the K850 practice. Book a place

Milestone forAn observable back-office agent

Make the workflow a state graph

Model ingest, match, review and act as explicit states with typed state, checkpoints and resumable runs. A run interrupted halfway through a month’s statement resumes without duplicating work.

Done when

  • A state graph with typed state and checkpoints
  • A run interrupted halfway through 300 lines resumes correctly
  • A test proving no duplicated actions after resume

Stretch: Add a human-review state that pauses the graph until approval

Reviews open with an access code.

Interview practice

Questions on this topic that AI engineering interviews ask, with the companies reported to ask them. Answer the way you would out loud; Jev scores it and DeepSeek tells you what to add.

Scoring opens with an access code. You can still read the questions and prepare.

Adapted from open-source work: AI Engineering from Scratch by Rohit Ghumare (MIT, lesson text, code and quizzes); Awesome LLM Apps by Shubham Saboo (Apache-2.0, starter code); AI Engineering Interview Questions by Outcome School (Apache-2.0, interview questions). Capstones, milestones, data packs and Zambian context by Zambrite.

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