The latest articles on DEV Community by Mugisha Billychriss (@mugisha_billychriss_e7fb6). https://dev.to/mugisha_billychriss_e7fb6 https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3974660%2Fefae0dcd-2bff-4ad5-8323-f2e6ee9370d1.png https://dev.to/mugisha_billychriss_e7fb6 en Mugisha Billychriss Mon, 08 Jun 2026 18:12:04 +0000 https://dev.to/mugisha_billychriss_e7fb6/the-cache-betrayal-build-a-self-healing-distributed-cache-that-never-loses-data-2m7g https://dev.to/mugisha_billychriss_e7fb6/the-cache-betrayal-build-a-self-healing-distributed-cache-that-never-loses-data-2m7g <p>You're working at "RwandaPay" — a fast-growing fintech processing thousands of transactions per second. Your caching layer (Redis) just crashed during peak hours. The result? 78,000 failed transactions. $450,000 lost.</p> <p>Your CTO says: "Build me a caching system that CANNOT lose data. Even if Redis dies. Even if the network splits. Even if servers catch fire. GO."<br> Build a distributed, fault-tolerant caching system with these impossible requirements:</p> <p>Core Requirements<br> Requirement Description Weight<br> No Single Point of Failure System works if any 2 nodes die 30%<br> Zero Data Loss Every cached write survives node failures 25%<br> Self-Healing Automatically recovers without manual intervention 20%<br> Eventual Consistency Within 5 seconds after healing 15%<br> Benchmark 10,000 ops/sec on consumer hardware 10%</p> architecture devchallenge distributedsystems systemdesign