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

20/01/2023 10 min read

Pub/Sub vs Message Queues: Architecture, Delivery Guarantees, and Scaling Patterns

Pub/Sub vs Message Queues decides if many readers share one event or one worker owns a task. Learn…
15/01/2023 11 min read

Rollback Strategies for Backend Systems: Blue-Green, Canary, and Database-Safe Reverts

Rollback Strategies for Backend Systems cover code, config, and data. Learn blue-green, canary, and when a database change…
15/01/2023 10 min read

JWT Rotation and Revocation: Secure Token Lifecycle in Distributed Systems

JWT Rotation and Revocation keeps distributed APIs safe after a key leak. Learn short lifetimes, key ids, denylists,…
18/12/2022 10 min read

Database Migrations at Scale: Zero-Downtime Schema Changes and Rollback Safety

Database Migrations at Scale need expand and contract steps. Learn how to change schemas with no downtime, keep…
20/11/2022 10 min read

Dead Letter Queues: Designing Failure Handling for Reliable Messaging

Dead Letter Queues hold messages that fail after retries so you can inspect, replay, or drop them. Learn…
25/10/2022 12 min read

Blue-Green vs Canary Deployment: Shipping Without Downtime

Blue green vs canary deployment decided: zero downtime deployment mechanics, the canary release strategy and its observation ramp,…
17/10/2022 11 min read

Clock Skew in Distributed Systems: Causes, Impact, and Clock Synchronization

Clock Skew in Distributed Systems breaks leases, caches, and event order. Learn the causes, the impact on reads,…
19/09/2022 10 min read

Health Checks in Distributed Systems: Liveness, Readiness, and Dependency Probes

Health Checks in Distributed Systems tell a platform if a task can serve traffic. Learn liveness, readiness, and…
23/08/2022 12 min read

Retry with Backoff and Jitter: Retrying Without Triggering Retry Storms

Retry with exponential backoff explained: backoff and jitter pacing, the retry storm math, retry budgets, what is safe…
22/08/2022 10 min read

Cron Jobs in Distributed Systems: Scheduling, Idempotency, and Missed Runs

Cron Jobs in Distributed Systems must run once, survive restarts, and stay idempotent. Learn locks, missed runs, jitter,…
25/07/2022 11 min read

Query Optimization for Backend Engineers: Indexes, Execution Plans, and Real-World Tuning

Query Optimization for Backend Engineers stops slow SQL from stalling APIs. Learn indexes, plans, and safe fixes you…
27/06/2022 10 min read

N+1 Queries: Detection, ORM Pitfalls, and Production Fixes

N+1 Queries hide inside ORM loops and then spike the database at peak load. Learn how to detect…
21/06/2022 14 min read

Disaster Recovery: RTO, RPO, and Getting Back Online

Disaster recovery explained: RTO and RPO as the two numbers that size the plan, the disaster recovery strategies…
30/05/2022 10 min read

Read Replicas: Architecture, Replication Lag, and Consistency Trade-offs

Read Replicas cut read load, but lag can show stale rows to real users. Learn routing rules, lag…