Interactive classroom
Try a decision. Watch the consequence. Then explain why.
Seven short activities connect the whole course. Pick a scene, change one condition, and compare the outcome. Every scene includes a concrete challenge and immediate feedback.
The missing receipt
A caller times out. Did the write happen?
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Runs in your browser with synthetic state. This is not a live etcd cluster. Read the concept · Inspect real evidence
Who could know what?
Select two events and trace their causal path.
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Runs in your browser with synthetic state. This is not a live etcd cluster. Read the concept · Inspect real evidence
Move a read through time
Drag a read across a write and see the model verdict change.
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Break a three-node cluster
Pause voters, replace the leader and try to commit.
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One intent, two effects?
Change the response delay and compare retry identities.
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Runs in your browser with synthetic state. This is not a live etcd cluster. Read the concept · Inspect real evidence
The worker that came back
Expire a lease, then decide which worker reaches the sink first.
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Runs in your browser with synthetic state. This is not a live etcd cluster. Read the concept · Inspect real evidence
Walk through a real run
Replay selected observations from all three saved repetitions.
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Ordered summaries from the saved JSON, not a packet-level replay. Read the concept · Inspect real evidence