Kubernetes 1.35 Timbernetes Deep Dive: Breaking Changes, In-Place Resize GA, Gang Scheduling

Kubernetes 1.35 "Timbernetes" dropped on December 17, 2025, and this is one of those releases that fundamentally changes how we operate clusters. This deep dive covers 60 enhancements, 3 breaking changes that will bite you if you're not prepared, and a headline feature six years in the making: In-Place Pod Resize graduating to GA.

⏰ Timestamps:
00:00 - Introduction to Kubernetes 1.35 Timbernetes
01:15 - Breaking Change #1: cgroup v1 REMOVED
03:00 - Breaking Change #2: containerd 1.x End of Support
04:45 - Breaking Change #3: IPVS Mode Deprecated
06:15 - In-Place Pod Resize GA (KEP-1287) - 6 Years in Making
10:15 - Pod Certificates Beta (KEP-4317) - Native Workload Identity
12:30 - Gang Scheduling Alpha (KEP-4671) - AI Workload Support
15:00 - Alpha Features: Node Declared Features, Partitionable Devices
17:15 - Practical Upgrade Checklist
19:00 - Key Takeaways

🔗 Resources:
• Episode page: https://platformengineering.org/podca...
• Kubernetes 1.35 Release Blog: https://kubernetes.io/blog/2025/12/17...
• KEP-1287 In-Place Resize: https://github.com/kubernetes/enhance...
• KEP-4317 Pod Certificates: https://github.com/kubernetes/enhance...
• KEP-4671 Gang Scheduling: https://github.com/kubernetes/enhance...

📌 Key Points:
✅ cgroup v1 is GONE - kubelet refuses to start, upgrade your nodes NOW
✅ containerd 1.x EOL - 1.35 is the LAST release supporting containerd 1.7
✅ IPVS deprecated - migrate to nftables mode by ~1.38
✅ In-Place Pod Resize: Change CPU/memory on running pods without restart
✅ Pod Certificates: Native mTLS without cert-manager or SPIRE
✅ Gang Scheduling: All-or-nothing scheduling for distributed AI training

#Kubernetes #K8s #PlatformEngineering #DevOps #CloudNative #Timbernetes #ContainerOrchestration #InPlaceResize #GangScheduling #AI #ML #SRE #InfrastructureAsCode #CNCF