FIRST SESSION · ABOUT 10 MINUTES · NO INSTALLATION

Follow one MicroBank request.

Predict, inspect a prepared example, and save one observation. You need only this browser.

1. Predict

Accounts accepts a request while Ledger is paused. Does that prove the expected Ledger entry already exists?

Your prediction Yes, acceptance proves completion No, Ledger needs separate evidence

2. Try and inspect

Prepared scenario

Choose a prediction, then load an example.

API caller
Accounts + outbox
Publisher → SNS → SQS
Ledger + database

3. Explain and save evidence

In your own words: what did you observe, and what remains unproven?

Pass when you identify the caller, Accounts, messaging and Ledger; distinguish acceptance from completion; and record one observation with its scope.

Hint and answer guide

Compare the matching-entry count in both scenarios. Accounts stays pending in this selected teaching reference even when the Ledger entry exists. The real HTTP 200 on this page proves the JSON fixture was served, not that a banking request ran. Your explanation should keep those two observations separate.

Small challenge

Load the other scenario. Which observation changes? Keep the same acceptance question. Save the difference, then explain why a healthy page or accepted API request is insufficient evidence for a completed deposit.