System Design

These system design guides cover how to build software that scales and stays up. There are over a hundred posts, grouped by topic.

For a start, read load balancing and caching. Then high availability covers uptime. Also, each sub section goes deeper into one area.

112 articles

01/09/2017 10 min read

XSS Prevention for Backend Engineers: Output Encoding, CSP, and Trust Boundaries

XSS Prevention for Backend Engineers covers encoding, CSP, and trust lines. Learn where output must be escaped and…
20/08/2017 10 min read

Helm Charts for Kubernetes: Packaging, Templating, Versioning, and Release Strategies

Helm Charts for Kubernetes covers packaging, templates, versions, and releases. Learn what breaks on upgrade, how to pin…
19/08/2017 11 min read

Redis Caching: Patterns for Real Workloads

Redis caching in practice: cache-aside with a TTL on every write, the redis TTL strategy, and the stampede,…
16/06/2017 9 min read

Cache Failure Modes: Stampede, Avalanche, and Penetration

The three ways caches fail when it matters: the cache stampede on an expired key, cache avalanche from…
15/06/2017 10 min read

Kubernetes for Backend Engineers: Architecture, Scheduling, Autoscaling, and Failure Modes

Kubernetes for Backend Engineers covers scheduling, autoscaling, and failure modes. Learn how pods fail, how to set limits,…
14/04/2017 12 min read

Distributed Caching: Architecture and Invalidation Across Nodes

Distributed caching beyond one node: consistent-hash routing, cache tiers, hot keys, cross-node invalidation, and the redis vs memcached…
10/02/2017 12 min read

Caching in System Design: Patterns, Eviction, and Hit Ratio

Cache-aside vs read-through, write-through vs write-back, LRU eviction, and the hit-ratio math that decides whether a cache pays…
09/12/2016 11 min read

L4 vs L7 Load Balancing: Where the Balancer Looks

L4 vs L7 load balancing compared: the layer 4 load balancer's connection-level speed, the layer 7 load balancer's…
20/10/2016 10 min read

Memory Leaks in Backend Services: Diagnosis, Tools, and Production Fixes

Memory Leaks in Backend Services grow RSS until the host kills the process. Learn how to find retained…
07/10/2016 12 min read

Long Polling vs Server-Sent Events: Choosing a Push Strategy

Long polling vs SSE compared: how server sent events work, where websockets fit, sse vs polling costs, and…
05/09/2016 9 min read

Garbage Collection Tuning for Backend Engineers: Latency, Throughput, and Pauses

Garbage Collection Tuning cuts pause time without starving throughput. Learn which collector to pick, which knobs matter, and…
05/08/2016 12 min read

WebSockets in System Design: When You Need a Persistent Connection

What are websockets: the websocket vs http comparison, the websocket connection lifecycle in six steps, and scaling websocket…
10/07/2016 11 min read

Dependency Hell in Backend Systems: Version Conflicts, Lockfiles, and Upgrade Strategies

Dependency Hell in Backend Systems breaks builds when library versions clash. Learn lockfiles, upgrade paths, and how to…
03/06/2016 11 min read

Rate Limiting in System Design: Algorithms and Distributed Enforcement

The rate limiting algorithms that matter (token bucket, leaky bucket, sliding window) how distributed enforcement works across a…