Engineering & Guides

System Design

37 articles on system design.

Glowing AI agent pipeline rerouting around a broken link through circuit-breaker and retry nodes
System Design

Fault Tolerance for AI Agent Pipelines: Retry and Recovery Patterns

How to build a fault tolerant AI agent pipeline with retries, circuit breakers, checkpoints, dead-letter queues, and graceful degradation so one failed step never crashes the whole run.

11 min read Aug 14, 2026Read
Supervisor agent coordinating subagents in a hierarchical architecture
System Design

Hierarchical Agent Architecture: The Supervisor Agent Pattern

The supervisor agent pattern turns a chaotic flat multi-agent system into a clean hierarchy. Here is how to design the routing, state, and error recovery.

9 min read Aug 13, 2026Read
Cascading failure spreading across data center server racks
System Design

Cascading Failure: When One Command Takes Down Everything

How a single mistyped command sparked the 2017 AWS S3 outage, why cascading failures spread through dependencies and retries, and the patterns that stop them.

7 min read Aug 11, 2026Read
Ride-hailing geospatial matching illustration: a city map with location pins and cars connected to a central dispatch hub
System Design

Uber System Design: Geospatial Matching, Surge Pricing, ETA

Design Uber the way interviewers want: a spatial index at the center, with geospatial matching, real-time surge pricing, and ML-based ETA prediction built on top.

11 min read Aug 10, 2026Read
Zero downtime database migration: data flowing from an old database to a new database over parallel tracks
System Design

Zero Downtime Database Migration: The Cassandra Story

A zero downtime database migration lets you move off Cassandra while users keep reading and writing. Here are the five phases, using Discord's move to ScyllaDB as the example.

7 min read Aug 9, 2026Read
Synchronous vs asynchronous communication: request-response, fire-and-forget, and event-driven patterns
System Design

Synchronous vs Asynchronous Communication Explained

The choice between synchronous and asynchronous communication shapes latency, failure modes, and coupling. Here is how request-response, fire-and-forget, and event-driven differ, and when to use each.

8 min read Aug 8, 2026Read
Four caching strategies for system design
System Design

4 Caching Strategies for System Design

Master cache-aside, read-through, write-through, and write-behind patterns. Learn when each strategy wins, what breaks, and how to explain the tradeoffs in system design interviews.

13 min read Aug 3, 2026Read
AI guardrails: a language model core wrapped in four protective checkpoint layers
System Design

AI Guardrails: How to Build a Safe LLM Application

AI guardrails are the safety layers around a language model: input filtering, output validation, content classification, and human-in-the-loop escalation. A system design guide with code.

9 min read Jul 27, 2026Read
Vector embedding models in production: generation, versioning, drift detection, and incremental updates
System Design

Vector Embedding Models: Generation, Versioning, and Drift

How to run vector embedding models in production: batch and real-time generation, versioning without breaking your index, drift detection, and incremental updates.

10 min read Jul 26, 2026Read