Distributed Systems Case Studies
Real-world Distributed Systems case studies: what happened in production, the architecture behind it, the numbers and the lessons to take to your own team.
How a B2B SaaS Team Built Multi-Region DR on AWS with a Tested 15-Minute RTO
A 120-engineer SaaS company replaced a single-region architecture with active-passive multi-region DR on AWS, cutting RTO from 4+ hours to under 15 minutes through automation, chaos testing, and disciplined runbook engineering.
Distributed Systems · advanced · 12 min read
How Backoff, Jitter, and Circuit Breakers Stopped a Retry Storm from Killing a Production Database
A slow Postgres instance triggered aggressive client retries that amplified load 40x, causing a full outage. Exponential backoff, jitter, and a circuit breaker pattern restored stability within one sprint.
Distributed Systems · intermediate · 12 min read
The 73-Hour Roblox Outage: How Consul Streaming and BoltDB Contention Took Down 50 Million Users
In October 2021, a Consul misconfiguration triggered BoltDB write contention that cascaded into a 73-hour total outage for Roblox, affecting 50M+ daily users. The lesson: service-mesh health depends on the databases underneath it.
Distributed Systems · advanced · 12 min read
The October 2025 DynamoDB Outage: How a DNS Automation Race Condition Took Down US-EAST-1
A race condition in AWS's internal DNS automation triggered a cascade that made DynamoDB unavailable in us-east-1 for several hours, taking down thousands of dependent services with it.
Distributed Systems · advanced · 12 min read