EO Engineering Learning OS
PROJECT LADDER · P08
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CORE PROJECT · TARGET L3 · 5–7 days
P08

CI/CD

Turn reviewed source into tested, versioned and recoverable deployments.

01 / CONCEPT MAP

Know what the parts mean.

Learn each concept deeply enough to recognize it, place it in the system and reason about normal and failed behavior.

01

Triggers

Define it · locate it · observe it · explain its failure mode.

02

Build and test

Define it · locate it · observe it · explain its failure mode.

03

Security scan

Define it · locate it · observe it · explain its failure mode.

04

Artifact

Define it · locate it · observe it · explain its failure mode.

05

Deployment

Define it · locate it · observe it · explain its failure mode.

06

Verification and rollback

Define it · locate it · observe it · explain its failure mode.

02 / SYSTEM FLOW

Trace it end to end.

Pull request→tests→scan→artifact→approval→deploy→verify→rollback

For every transition: identify input, output, identity, protocol, state, trust boundary, evidence and owner.

03 / GUIDED BUILD

Build, observe and explain.

Documentation and AI are allowed. The engineer must review every output and demonstrate the result from direct evidence.

  1. 01Create PR checks
  2. 02Build immutable artifact
  3. 03Store version metadata
  4. 04Deploy to non-production
  5. 05Add approval gate
  6. 06Verify and roll back
04 / INCIDENT

Deployment succeeds technically but serves the previous artifact due to mutable tagging.

Required investigation

State impact → collect evidence → form competing hypotheses → test the cheapest discriminator → isolate root cause → contain → correct → verify.

Evidence pack

Timeline, relevant logs/metrics, failed assumptions, root cause, correction, verification and one prevention action.

AI ownership

AI may suggest causes and commands. The engineer must explain why each check is safe, what result is expected and how the result changes the hypothesis.

05 / DESIGN CHALLENGE

Defend the decision.

Choose deployment and rollback strategy based on risk and downtime tolerance.

06 / VERIFY, SUBMIT & REVIEW

Submission evidence

Architecture review

  • Explain ci/cd without relying on memorized commands.
  • Draw the flow and name what crosses every arrow.
  • Identify the most likely, highest-impact and hardest-to-detect failure.
  • Show the evidence that proves the solution works.
  • Defend one security, reliability and cost trade-off.

Definition of Done

  • Acceptance criteria pass
  • Flow is drawn and explained
  • Security implications considered
  • Logs/metrics checked
  • Failure is tested
  • AI output is understood
  • Runbook is reusable
  • Mentor review passes
07 / MENTOR GUIDE

Do not score memory. Score the engineer’s ability to form a model, collect evidence, make a safe change and defend the trade-off.

1 Cannot explain2 Understands with gaps3 Implements and troubleshoots4 Designs and reviews