Event-Driven Notifications Platform
Migrated notifications and activity processing from a monolith to an event-driven serverless architecture.
- Problem
- Notifications and activity processing were tightly coupled inside a monolith, making them hard to scale and operate independently.
- Approach
- Re-architected the pipeline around events — decoupling producers and consumers with SNS and Kinesis, persisting state in DynamoDB, and processing asynchronously with Lambda.
- Technologies
- Node.jsAWS LambdaSNSKinesisDynamoDB
- Impact
- Scaled to over 1M events per day while maintaining sub-400ms response times, with clearer retries and ownership.
- Lessons
- Event-driven systems trade simplicity for scale — idempotency, retries, and observability have to be designed in, not bolted on.