Migrating from ECS to Kubernetes sounds straightforward — until you hit spot capacity failures, firewall rules silently dropping traffic, and memory metrics that lie to your autoscaler.

Radosław Miernik, Head of Engineering at aleno, walks through a real production migration: what broke, what they missed, and the fixes that made it work.

In this interview:

• Running Flux and Argo CD together — Flux for the infra team, Argo CD's UI for developers who don't want to touch YAML

• How the wrong memory metric caused OOM errors, and why switching to jemalloc cut memory usage by 20%

• Splitting WebSocket and API containers into separate deployments with independent autoscaling

Four months of migration, over 100 configuration changes in the first month, and a concrete breakdown of what platform work looks like when you can't afford downtime.

Sponsor

This episode is sponsored by LearnKube — get started on your Kubernetes journey through comprehensive online, in-person or remote training.

More info

• Find all the links and info for this episode here: https://ku.bz/x6wFMhVsx

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