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

02/10/2019 10 min read

WAF in Modern Backends: Rules, Bypass Risks, and Defense in Depth

WAF in Modern Backends stops bad requests before your app. Learn rule design, false positives, logging, and how…
04/09/2019 10 min read

SSRF Attacks and Defenses: URL Parsing, Allowlists, and Cloud Metadata

SSRF Attacks and Defenses stop your servers from fetching attacker URLs. Learn allowlists, DNS checks, metadata blocks, and…
01/06/2019 11 min read

Secrets Management for Backend Systems: Vaults, Rotation, and Least Privilege

Secrets Management for Backend Systems keeps passwords and keys out of code and logs. Learn vaults, rotation, least…
15/05/2019 10 min read

Alerting That Works: Signal, Noise, and On-Call SLOs

Alerting That Works pages you for real user pain, not every small blip. Learn how to cut noise,…
01/04/2019 10 min read

Error Budgets: Balancing Reliability, Velocity, and Product Risk

Error Budgets tell you how much failure you can spend. Learn how to balance reliability, ship speed, and…
25/02/2019 10 min read

SLOs for Backend Engineers: Defining, Measuring, and Enforcing Service Objectives

SLOs for Backend Engineers turn user pain into a clear number. Learn how to define, measure, and enforce…
20/01/2019 10 min read

SLIs Explained: Choosing the Right Service Level Indicators

SLIs Explained shows which signals match real user pain. Learn how to pick indicators for latency, errors, and…
20/01/2019 9 min read

IAM for Backend Engineers: Roles, Policies, and Least-Privilege Design

IAM for Backend Engineers shows how roles and policies limit blast radius. Learn least privilege, short sessions, and…
26/12/2018 10 min read

gRPC vs REST: Protocol Buffers, Streaming, and Production Trade-offs

gRPC vs REST compares protocol buffers, streaming, and JSON APIs so you can pick a contract that stays…
10/12/2018 11 min read

Tail Latency: Why P99 Matters More Than Averages in Distributed Systems

Tail Latency is the slow slice users actually feel. Learn why averages lie, how fan-out multiplies delay, and…
05/11/2018 10 min read

P99 Latency Explained: Measurement, Debugging, and SLOs

P99 Latency Explained for engineers who own production SLOs. Learn how to measure the slow percentile, debug the…
20/10/2018 10 min read

Encryption at Rest: Key Management, Envelope Encryption, and Compliance

Encryption at Rest protects disks, backups, and columns when storage is copied. Learn envelope keys, KMS control, rotation,…
25/09/2018 11 min read

Distributed Tracing: Following One Request Across Many Services

What is distributed tracing: the span and trace model, context propagation across services and queues, OpenTelemetry tracing and…
15/09/2018 10 min read

Encryption in Transit: mTLS, TLS Termination, and Service-to-Service Security

Encryption in Transit protects service calls from network snooping. Learn TLS termination, mTLS, cert rotation, and the gaps…