EO Engineering Learning OS
PROJECT LADDER · P11
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CORE PROJECT · TARGET L4 · 7 days
P11

Security hardening

Reduce attack surface and improve prevention, detection and recovery across the system.

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

Threat modeling

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

02

Patching

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

03

Secrets

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

04

Scanning

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

05

Least privilege

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

06

Audit

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

02 / SYSTEM FLOW

Trace it end to end.

Code→scan→artifact→runtime controls→audit→response

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. 01Threat-model system
  2. 02Patch baseline
  3. 03Centralize secrets
  4. 04Scan code/artifact
  5. 05Reduce IAM and network exposure
  6. 06Test audit and response
04 / INCIDENT

A dependency vulnerability is exploitable only on a publicly reachable path; prioritize response using evidence.

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.

Create a risk-based hardening roadmap rather than an unranked checklist.

06 / VERIFY, SUBMIT & REVIEW

Submission evidence

Architecture review

  • Explain security hardening 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