devgeist

Series

Multi-part arcs, front to back. · all posts

Series Kubernetes Through Control Theory Glasses

  1. Part 1 Kubernetes Steering Wheel

    2026.05.13 · 17 min

    Exploring Kubernetes HPA through control theory: dead time, windup, offset — and why HPA's math is smarter than it looks.

Series Ordered Retries in Kafka

  1. Part 1 When the Retry Topic Breaks Ordering

    2026.03.10 · 8 min

    Retry topics keep throughput high but break ordering. Learn why Kafka retries fail for stateful systems and how to maintain message order.

  2. Part 2 The Bugs You'll Find in Production

    2026.03.17 · 13 min

    Implementation gaps in Kafka's ordered retry pattern: the per-key locking edge cases and production bugs the whiteboard diagrams don't show.

  3. Part 3 Why You Probably Shouldn't Build This

    2026.03.24 · 8 min

    The operational cost of maintaining message ordering in Kafka with distributed locks — and when simpler alternatives are the better choice.

Series API Testing with Simulations

  1. Part 1 API Testing with Simulations: Record and Replay

    2025.02.23 · 8 min

    Why mock when you can simulate? Discover how to capture real API behavior and replay it in your tests to save costs, reduce latency, and improve reliability.

  2. Part 2 API Testing with Simulations: When Record-and-Replay Breaks

    2025.03.23 · 14 min

    Real-world API simulation challenges beyond the basics: dynamic data, stateful interactions, and the edge cases that break naive record-and-replay setups.