KubeFM

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

• Interested in sponsoring an episode? Learn more.

Kubernetes nodes on EKS can take over a minute to become ready, and pods often wait even longer — but most teams never look into why.

Jan Ludvik, Senior Staff Reliability Engineer at Outreach, shares how he cut node startup from 65 to 45 seconds and reduced P90 pod startup by 30 seconds across ~1,000 nodes — by tackling overlooked defaults and EBS bottlenecks.

In this episode:

• Why Kubelet's serial image pull default quietly blocks pod startup, and how parallel pulls fix it

• How EBS lazy loading can silently negate image caching in AMIs — and the critical path workaround

• A Lambda-based automation that temporarily boosts EBS throughput during startup, then reverts to save cost

• The kubelet metrics and logs that expose pod and node startup latenc,y most teams never monitor

Every second saved translates to faster scaling, lower AWS bills, and better end-user experience.

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/B7TzKXyxf

• Interested in sponsoring an episode? Learn more.

You self-host services at home, but upgrades break things, rollbacks require SSH-ing in to kill containers manually, and there's no safety net if your hardware fails.

Thibault Martin, Director of Program Development at the Matrix Foundation, walked this exact path — from Docker Compose to Podman with Ansible to Kubernetes on a single server — and explains why each transition happened and what it solved.

In this interview:

• Why Ansible's declarative promise fell short with the Podman collection, forcing sequential imperative steps instead of desired-state definitions

• How community Helm charts replace the need to write and maintain every manifest yourself

• Why GitOps isn't just a deployment workflow — it's a disaster recovery strategy when your infrastructure lives in your living room

• How k3s removes the barrier to entry by bundling opinionated defaults so you can skip choosing CNI plugins and storage providers

Kubernetes doesn't have to be enterprise-scale — with the right distribution and community tooling, it can be a practical, low-overhead choice for anyone who cares about their data.

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/Xk5S7VqXz

• Interested in sponsoring an episode? Learn more.

Your database backup strategy shouldn't be the thing that takes your production systems down.

Ziv Yatzik manages 600+ Postgres clusters in a closed network environment with no public cloud. After existing backup solutions proved unreliable — causing downtime when disks filled up — his team built a new architecture using pgBackRest, Argo CD, and Kubernetes CronJobs.

In this episode:

• Why storing WAL files on shared NAS storage prevents backup failures from cascading into database outages

• How GitOps with Argo CD lets them manage backups for hundreds of clusters by adding a single YAML file

• The Ansible + Kubernetes hybrid approach that keeps VM-based Patroni clusters in sync with Kubernetes-orchestrated backups

A practical blueprint for making database backups boring, reliable, and safe.

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/Rg_sQYSmw

• Interested in sponsoring an episode? Learn more.

Most developers assume Kubernetes requires an enterprise budget. Varnit Goyal proves otherwise — he built a full three-node Kubernetes cluster for $2.16/month using Rackspace Spot Instances.

The trick: pick non-default instance types, distribute nodes across low-demand regions, and let Kubernetes handle rescheduling when nodes get preempted. For service exposure, he replaced the $10/month load balancer with Tailscale Funnel — free.

In this episode:

• How Spot Instance bidding works and which strategies keep costs and preemption low

• Using Tailscale Kubernetes operator as a free alternative to traditional load balancers

• Running real development dependencies (Kafka, Elasticsearch, Postgres) on a budget cluster

A practical walkthrough of what Kubernetes actually needs to function — and what you can strip away.

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/HpVyQMVv0

• Interested in sponsoring an episode? Learn more.

Dilshan Wijesooriya, Senior Cloud Engineer, discusses a real incident where migrating EKS nodes to AL2023 caused the cluster autoscaler to lose AWS permissions silently.

You will learn:

• Why AL2023 blocks pod access to instance metadata by default, breaking components that relied on node IAM roles (like cluster autoscaler, external-DNS, and AWS Load Balancer Controller)

• How to implement IRSA correctly by configuring IAM roles, Kubernetes service accounts, and OIDC trust relationships, and why both AWS IAM and Kubernetes RBAC must be configured independently

• The recommended migration strategy: move critical system components to IRSA before changing AMIs, test aggressively in non-production, and decouple identity changes from OS upgrades

• How to audit which pods currently rely on node roles and clean up legacy IAM permissions to reduce attack surface after migration

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/T_YPfTfDb

• Interested in sponsoring an episode? Learn more.

Fabián Sellés Rosa, Tech Lead of the Runtime team at Adevinta, walks through a real engineering investigation that started with a simple request: allowing tenants to use third-party Kafka services. What seemed straightforward turned into a complex DNS resolution problem that required testing seven different approaches before a working solution was found.

You will learn:

• Why Kafka's multi-step DNS resolution creates unique challenges in multi-tenant environments, where bootstrap servers and dynamic broker lists complicate standard DNS approaches

• The iterative debugging process from Route 53 split DNS through Kubernetes native pod DNS config, custom DNS servers, Kafka proxies, and CoreDNS solutions

• How to implement the final solution using node-local DNS and CoreDNS templating with practical details including ndots configuration and Kyverno automation

• Platform engineering evaluation criteria for assessing solutions based on maintainability, self-service capability, and evolvability in multi-tenant environments

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/NsBZ-FwcJ

• Interested in sponsoring an episode? Learn more.

Amos Wenger walks through his production incident where adding a home computer as a Kubernetes node caused TLS certificate renewals to fail. The discussion covers debugging techniques using tools like netshoot and K9s, and explores the unexpected interactions between Kubernetes overlay networks and consumer routers.

You will learn:

• How Kubernetes networking assumptions break when mixing cloud VMs with nodes behind consumer routers, and why cert-manager challenges fail in NAT environments

• The differences between CNI plugins like Flannel and Calico, particularly how they handle IPv6 translation

• Debugging techniques for network issues using tools like netshoot, K9s, and iproute2

• Best practices for mixed infrastructure including proper node labeling, taints, and scheduling controls

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/6Ll_7slr9

• Interested in sponsoring an episode? Learn more.

Tanat Lokejaroenlarb shares the complete journey of replacing EKS Managed Node Groups and Cluster Autoscaler with AWS Karpenter. He explains how this migration transformed their Kubernetes operations, from eliminating brittle upgrade processes to achieving significant cost savings of €30,000 per month through automated instance selection and AMD adoption.

You will learn:

• How to decouple control plane and data plane upgrades using Karpenter's asynchronous node rollout capabilities

• Cost optimization strategies including flexible instance selection, automated AMD migration, and the trade-offs between cheapest-first selection versus performance considerations

• Scaling and performance tuning techniques such as implementing over-provisioning with low-priority placeholder pods

• Policy automation and operational practices using Kyverno for user experience simplification, implementing proper Pod Disruption Budgets

Sponsor

This episode is sponsored by StormForge by CloudBolt — automatically rightsize your Kubernetes workloads with ML-powered optimization

More info

• Find all the links and info for this episode here: https://ku.bz/T6hDSWYhb

• Interested in sponsoring an episode? Learn more.

Festus Owumi walks through his project of building a lightweight version of Kubernetes in Go. He removed etcd (replacing it with in-memory storage), skipped containers entirely, dropped authentication, and focused purely on the control plane mechanics. Through this process, he demonstrates how the reconciliation loop, API server concurrency handling, and scheduling logic actually work at their most basic level.

You will learn:

• How the reconciliation loop works - The core concept of desired state vs current state that drives all Kubernetes operations

• Why the API server is the gateway to etcd - How Kubernetes prevents race conditions using optimistic concurrency control and why centralized validation matters

• What the scheduler actually does - Beyond simple round-robin assignment, understanding node affinity, resource requirements, and the complex scoring algorithms that determine pod placement

• The complete pod lifecycle - Step-by-step walkthrough from kubectl command to running pod, showing how independent components work together like an orchestra

Sponsor

This episode is sponsored by StormForge by CloudBolt — automatically rightsize your Kubernetes workloads with ML-powered optimization

More info

• Find all the links and info for this episode here: https://ku.bz/pf5kK9lQF

• Interested in sponsoring an episode? Learn more.