EO Engineering Learning OS
PROJECT LADDER · P05
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CORE PROJECT · TARGET L3 · 4–5 days
P05

Amazon RDS for MySQL

Replace the server-managed MySQL instance with a managed database while preserving application behavior.

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

RDS lifecycle

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

02

DB subnet groups

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

03

Security groups

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

04

Connection configuration

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

05

Backups and maintenance

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

02 / SYSTEM FLOW

Trace it end to end.

FastAPI→DB security rule→RDS endpoint→MySQL→backup

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 private RDS
  2. 02Create schema and user
  3. 03Migrate data
  4. 04Update application configuration
  5. 05Verify backup settings
  6. 06Remove old database dependency
04 / INCIDENT

Application times out because the database path, DNS or security rules are wrong.

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.

Compare self-managed MySQL and RDS across control, operations, availability and cost.

06 / VERIFY, SUBMIT & REVIEW

Submission evidence

Architecture review

  • Explain amazon rds for mysql 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