Module 3: Cloud Deployment & CI/CD: Mistake Clinic

This clinic turns wrong moves into reusable judgment. Use it after each practice page and again before the quiz or checkpoint.

---

Module-Specific Mistake Radar

Start with these traps. Replace or extend them with real mistakes from your own work.

Mistake to look for	Where it shows up	Symptom	Repair evidence
Finishing Topology and IaC Lab with only a final answer	Topology and IaC Lab	The work has no failed case, trace, test, proof gap, or design stress point.	Add the smallest broken example and show the repair that changes the result.
Finishing Pipeline Wiring Workshop with only a final answer	Pipeline Wiring Workshop	The work has no failed case, trace, test, proof gap, or design stress point.	Add the smallest broken example and show the repair that changes the result.
Finishing Release and Rollback Clinic with only a final answer	Release and Rollback Clinic	The work has no failed case, trace, test, proof gap, or design stress point.	Add the smallest broken example and show the repair that changes the result.
Finishing Deployment Katas with only a final answer	Deployment Katas	The work has no failed case, trace, test, proof gap, or design stress point.	Add the smallest broken example and show the repair that changes the result.
Treating Choosing \ as vocabulary instead of a tool	[Choosing ](concepts/cluster-01-a-minimal-deployable-capstone/01-choosing-small-enough-cloud-primary.md)	The explanation names the concept but cannot decide between two cases.	Write one example, one non-example, and the rule that separates them.
Treating The Capstone Deployment Topology as vocabulary instead of a tool	The Capstone Deployment Topology	The explanation names the concept but cannot decide between two cases.	Write one example, one non-example, and the rule that separates them.

---

Practice Mistake Checks

Pull any miss from these checks into your mistake log.

Topology and IaC Lab

Source: practice/01-topology-and-iac-lab.md

For each statement, identify the error:

1. "We use AWS because it's the biggest, not because it fits the capstone."
2. "Our staging is four weeks behind prod; it still catches bugs."
3. "I committed .env.example with real values so new developers have a working starting point."
4. "We wrapped a single Cloud Run resource in a module to keep things tidy."
5. "We skipped setting up a locking backend because we're a team of one."

Pipeline Wiring Workshop

Source: practice/02-pipeline-wiring-workshop.md

For each statement, identify the error:

1. "My OIDC trust uses sub: repo:org/capstone:* so any branch can deploy."
2. "I put id-token: write at the top of the workflow because it's easier."
3. "We run terraform apply on every PR to see what it would do."
4. "Our preview environments have never been torn down and that's fine because none of them get traffic."
5. "I'll commit the AWS access key to a repo secret; rotation handles it."

Release and Rollback Clinic

Source: practice/03-release-and-rollback-clinic.md

For each statement, identify the error:

1. "My migration tool has --rollback so I can always revert data changes."
2. "Rolling back is shameful; we always roll forward."
3. "The smoke test calls /healthz and that's enough."
4. "I'll leave the feature flag in place indefinitely, just in case."
5. "I shipped a rename and a contract in the same PR to save a deploy."

---

Repair Protocol

For each real mistake:

1. Reproduce the failure on the smallest example, trace, proof, query, command, or design sketch.
2. Name the hidden assumption.
3. Repair the artifact.
4. Save evidence that changed: failing then passing test, corrected proof step, revised diagram, safer command, benchmark, or review note.
5. Add one retrieval card beginning with Check... before... or Do not use... when....

---

Mistake Log

Date	Mistake	Symptom	Root cause	Repair evidence	Retrieval card
Starter	Pick one radar row above	Explain how it would fail in this module	Name the assumption	Add a counterexample or corrected artifact	Write the card before closing the page

---

Completion Standard

• At least five real mistakes are logged.
• At least two mistakes include a counterexample or failing test.
• At least one mistake connects to an older semester skill.
• At least one correction changes code, a proof, a diagram, a command transcript, a query, or a design decision.