LOCKEDIN / FORWARD-DEPLOYED ENGINEERING 101
Understand it.
Then build it.
You can be an experienced engineer and still be new to agents. Start with what each thing is and how it helps a person do useful work. Explore 48 original introductions across software, agents, cloud, security and delivery. Start here without a model key; each topic connects to deeper instruction and practice.
- 101UnderstandPlain language, visual walkthrough, vocabulary
- 102Build with guidanceOriginal lessons, examples and knowledge checks
- 103Practise and explainRunnable labs, failure cases and handover
- 01Draw the steps
- 02Carry the work
- 03Wait and resume
An open-source orchestration framework and runtime
What is LangGraph?
LangGraph is a software framework for coordinating the steps of an application. You describe steps as a graph: what each step does, what information it carries forward and which step happens next. It is especially useful when work branches, waits for a person or needs to resume after a failure. You write code in Python or JavaScript; LangGraph is not a separate language or an AI model.
Client workflows rarely finish with one model call. An FDE may need to pause a draft for approval, keep the work while someone reviews it, and resume the same request without starting over.
CONNECT IT TO WHAT YOU KNOW
Start with something familiar.
If you know a state machine or a build pipeline, start there. LangGraph lets you write named steps and transitions around shared working data, including work that waits for a person or survives a restart.
A graph is an explicit workflow representation. LangGraph is the framework that runs it. Python or JavaScript is the language you use to write it; the model is a separate component you may call from a step.
Words worth knowing
- Graph
- A map of steps and the connections between them.
- Node
- A function that performs one step.
- Edge
- A connection or rule that chooses the next step.
- State
- The information passed between steps, such as the request and current draft.
- Checkpoint
- A saved snapshot used to continue the work later.
- Interrupt
- A deliberate pause, often to wait for a person's input.
ONE EXAMPLE / FICTIONAL CASE
Watch the work take shape.
Picture a request moving between desks: look up a procedure, draft a reply, ask a person to approve it, then record the outcome. LangGraph coordinates those steps. An AI model may write the draft, but ordinary code can perform the lookup and enforce the approval rule.
- 01Draw the steps
- 02Carry the work
- 03Wait and resume
Draw the steps
Create lookup, draft and review steps. A node is simply one step; an edge describes where work can go next.
Lookup → Draft → Human reviewA workflow that waits for a person
Original silent explainer · Optional English captions
Read the visual transcript
- Draft: a step writes a proposal and its version into shared state.
- Pause: save the state while a person reviews that exact proposal. Waiting is an explicit state, not a running model call.
- Resume: check that the decision matches the current proposal. Continue on acceptance; otherwise stop or request a new review.
FROM RECOGNITION TO REASONING
Draw a three-step maintenance workflow with a pause.
- 01
Draw draft → human review → accepted or stopped.
- 02
List the draft identifier and version that must survive while waiting.
- 03
Change the draft after review and explain why the old decision cannot approve the new content.
A state sketch with a stale-review rejection case.
Compare your reasoning when you are ready
The saved state must identify the exact proposal being reviewed. Resuming a graph cannot make an old decision valid for changed content; the application checks the current version.
Keep notes in your own working copy. Moving through these cards does not record completion.
TURN THE IDEA INTO USEFUL WORK
You can now go deeper.
LangChain helps assemble model-and-tool agents. LangGraph gives you explicit control over the path and saved work. You can use LangGraph without LangChain, and graph steps do not all need AI.
Academy lessons use your existing training access. Free guides stay open.
Learn with the original creators
Start with Motivation and Simple Graph. Then compare its state-and-transition model with the illustration here. Provider registration may be required.