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

20/08/2018 11 min read

Metrics: Golden Signals, RED, and USE

Metrics monitoring for a distributed fleet: time series metrics (counters, gauges, histograms) the four golden signals, RED vs…
08/08/2018 10 min read

Terraform in Production: Modules, State, Workspaces, and Drift Management

Terraform in Production covers modules, state, workspaces, and drift. Learn how state locks fail, how to split stacks,…
01/08/2018 10 min read

TLS for Backend Engineers: Handshakes, Certificates, and Production Hardening

TLS for Backend Engineers covers handshakes, certificates, and trust stores. Learn TLS 1.3 settings, rotation, and the failures…
15/07/2018 12 min read

Logging: Structured, Centralized, and Searchable

Structured logging, log levels, centralized logging, and log aggregation: how a distributed fleet turns scattered events into one…
11/07/2018 10 min read

Serverless Limits: Timeouts, Memory, Concurrency, and When Not to Use Serverless

Serverless Limits on time, memory, and concurrency shape every design. Learn the hard caps, the cost traps, and…
26/06/2018 10 min read

Edge Caching: CDN Strategies, Purge Patterns, and Personalization Trade-offs

Edge Caching stores responses near users. Learn CDN cache keys, purge patterns, and when personalization should bypass the…
13/06/2018 10 min read

Infrastructure as Code: Principles, Patterns, and Production Anti-Patterns

Infrastructure as Code shows how to define servers, networks, and policy in files. Learn patterns, anti-patterns, drift, and…
01/06/2018 13 min read

Monitoring and Observability: Knowing What Your System Is Doing

Observability vs monitoring, drawn honestly: what observability is as a property, the three pillars (logs, metrics, traces) the…
15/01/2018 10 min read

CORS Explained for Backend Engineers: Preflight, Credentials, and Security Pitfalls

CORS Explained for Backend Engineers covers origins, preflight, and credentials. Learn which headers to set, which to avoid,…
23/12/2017 12 min read

Cache Invalidation Strategies: Purges, Versioning, and Write-Through Choices

Cache invalidation strategies compared: delete-on-write, versioned cache keys, the cache purge, and write-through vs write-behind (plus the delivery…
20/11/2017 10 min read

CSRF Protection: Tokens, SameSite Cookies, and Modern Browser Defenses

CSRF Protection stops forged state changes from other sites. Learn tokens, SameSite cookies, and where browser defaults still…
21/10/2017 12 min read

Redis Architecture: Data Structures, Persistence, and High Availability

Redis architecture under the caching patterns: the single-threaded event loop, redis data structures, maxmemory eviction, rdb vs aof…
15/10/2017 10 min read

SQL Injection Prevention: Parameterized Queries, ORMs, and Defense in Depth

SQL Injection Prevention keeps queries bound to data, not to raw strings. Learn parameters, ORM limits, least privilege,…
10/10/2017 10 min read

Liveness vs Readiness Probes: Kubernetes Health Checks Done Right

Liveness vs Readiness Probes decide restart versus traffic. Learn Kubernetes settings that avoid crash loops, slow starts, and…