Topic hub
Networking
How networks really work for developers and cloud engineers: IP addressing and subnets, TCP, DNS, TLS, NAT, firewalls, load balancers and cloud VPC design, with interview questions and a quiz.
Lessons
- The Acquisition That Couldn't Connect · Cloud Networking in Production
Two networks with the same private range can't be peered or routed. Plan ranges centrally, and know the workarounds when you inherit an overlap. - Pods Stopped Scheduling · Cloud Networking in Production
Kubernetes and serverless workloads can consume a subnet's addresses fast. Size subnets for them, and use prefix delegation or secondary ranges. - Large Responses Hang Over the VPN · Cloud Networking in Production
When ICMP is blocked, Path MTU Discovery fails and big packets vanish. Allow the right ICMP, clamp MSS on tunnels, and test with real packet sizes. - Timeouts to One Partner API · Cloud Networking in Production
A NAT gateway can only open so many connections to one destination. Reuse connections, add NAT addresses, and watch the port-allocation metric. - The Network ACL That Broke Some Clients · Cloud Networking in Production
Stateless network ACLs must allow return traffic to ephemeral ports, and different clients use different ranges. Prefer security groups. - The Migration That Took Two Days · Cloud Networking in Production
DNS changes are only as fast as the longest cache. Lower TTLs in advance, shift traffic with weighted records, and know which clients cache on their own. - The Health Check That Took Everything Down · Cloud Networking in Production
Health checks that test shared dependencies mark every instance unhealthy at once. Keep load balancer checks shallow and about the instance. - Random 502s Behind the Load Balancer · Cloud Networking in Production
When the app closes idle keep-alive connections before the load balancer does, some requests land on dead connections. Keep the app's timeout longer.
Cookbook recipes
- Paginate and sort safely with Spring Data · Spring Boot
- Paginate and filter large API lists · Django
- Paginate with cursors in FastAPI · FastAPI
- Paginate and filter with searchParams in Server Components · Next.js
- Implement cursor pagination with PostgreSQL in Node.js · Node.js
- Paginate large tables with cursors in PHP · PHP
- Build infinite scroll with TanStack Query · React
- Sync filters and pagination with the URL · React
- Load more items with infinite scroll · Vue