System Design Drill Day 13: Designing a Multi-Channel Notification System
How to design a notification service with per-channel workers, priority queues, preferences, dedup and signed webhook retries.
Anish's Blog
Csharpcorner MVP |Software Engineer|IOT| Azure|microbit| Web Developer | Udacity Scholar
Latest articles
System Design Drill Day 12: The Saga Pattern for a Multi-Step Checkout
How sagas replace distributed transactions with local steps and compensations, using a multi-step checkout as the example.
System Design Drill Day 11: The Transactional Outbox Pattern
Why writing to the database and pushing to a queue can't be atomic, and how a transactional outbox fixes lost and phantom events.
System Design Drill Day 10: Circuit Breakers, Timeouts and Degradation
How circuit breakers, timeouts and bulkheads keep a checkout alive when the payment gateway or SMS provider starts failing.
System Design Drill Day 9: Idempotency Keys for Payments and Retries
Why retries make duplicates inevitable, and how idempotency keys stop double charges and double stock decrements.
System Design Drill Day 8: Distributed Locks with Redis and Fencing Tokens
How distributed locks work with Redis SET NX EX, why leases and fencing tokens matter, and where locks fit in a checkout.
System Design Drill Day 7: Rate Limiting APIs, Logins and OTPs with Redis
The main rate-limiting algorithms, how to run them atomically across servers with Redis and Lua, and when to fail open or closed.
System Design Drill Day 6: Sharding and Partitioning a MySQL Orders Table
How to split a MySQL orders table across shards: choosing a shard key, routing with logical shards, keeping reports off the shards and resharding.
System Design Drill Day 5: Load Balancing and Horizontal Scaling
How to go from one Laravel server to three behind a load balancer: algorithms, health checks, stateless servers and safe deploys.
