Resources and dependencies
Define it · locate it · observe it · explain its failure mode.
PROJECT LADDER · P07
Back to map ↑CORE PROJECT · TARGET L3 · 7 days
P07
Terraform
Describe infrastructure already understood as reviewable, repeatable code with controlled state.
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.
Variables and outputs
Define it · locate it · observe it · explain its failure mode.
State
Define it · locate it · observe it · explain its failure mode.
Plan/apply lifecycle
Define it · locate it · observe it · explain its failure mode.
Modules
Define it · locate it · observe it · explain its failure mode.
Drift and imports
Define it · locate it · observe it · explain its failure mode.
02 / SYSTEM FLOW
Trace it end to end.
Configuration→plan→review→apply→AWS resources→state→drift check
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.
- 01Model VPC and subnets
- 02Add EC2, RDS and IAM
- 03Separate configuration values
- 04Review plan
- 05Apply and verify
- 06Introduce and resolve safe drift
04 / INCIDENT
A change proposes database replacement because an immutable property changed.
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.
Define module boundaries, state isolation and approval policy for environments.
06 / VERIFY, SUBMIT & REVIEW
Submission evidence
Architecture review
- Explain terraform 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