Module 17: Ops Excellence

[!TIP] “Hope is not a strategy.” - SRE Motto

Designing a system is only 20% of the work. The other 80% is keeping it alive, secure, and performant in production. This module covers the “Day 2” operations that distinguish a Junior Engineer from a Senior/Staff Engineer.

You will learn how to verify your system is working (Observability), how to prevent one failure from taking down the whole ship (Reliability), how to lock the doors (Security), and how to change the engine while flying (Deployment).

Module Road Map

  1. Observability: Metrics, Logging & Tracing
    • Stop guessing. Learn to use the “Eyes of the System” to debug microservices instantly.
    • Key Concept: Cardinality Explosion, Distributed Tracing.
  2. Reliability Patterns: Circuit Breakers & Retries
    • Failures are inevitable. Learn how to fail gracefully without crashing.
    • Key Concept: Circuit Breaker, Bulkhead, Thundering Herd.
  3. Security Essentials: OAuth 2.0 & TLS 1.3
    • Secure your data in transit and manage access permissions like a pro.
    • Key Concept: TLS Handshake, OAuth 2.0 flows, JWT vs Sessions.
  4. Deployment Strategies: Blue/Green, Canary & Rolling
    • Deploy code without waking up at 3 AM. Zero-downtime releases.
    • Key Concept: Blue/Green, Canary, Feature Flags, GitOps.
  5. Module Review: Cheat Sheet & Flashcards
    • Review everything with interactive Flashcards and a “Panic Button” scenario.
    • Key Concept: Spaced Repetition.

Why This Matters for Interviews?

In System Design interviews, after drawing the boxes, the interviewer will ask:

  • “How do you know if the DB is slow?” (Observability)
  • “What if the Payment Service goes down?” (Reliability)
  • “How do we push this code to production safely?” (Deployment)

This module gives you the “Senior” answers to these questions.

Module Chapters