When a B2B marketplace approached us, they were struggling to handle 1,000 daily transactions. Eighteen months later, they're processing 10,000+ daily transactions with better performance and lower costs. Here's how we did it.
The Challenge
The platform was built on a monolithic architecture that couldn't scale. Database queries were slow, the search function was unreliable, payment processing frequently timed out, and the admin panel crashed under load. They needed a complete platform overhaul without disrupting existing operations.
Our Solution: Phased Migration to Microservices
- Phase 1: Migrated search to Elasticsearch (3x faster, 99.9% uptime)
- Phase 2: Separated payment processing into independent service
- Phase 3: Implemented event-driven architecture for real-time updates
- Phase 4: Moved to containerized infrastructure on AWS ECS
Technical Architecture
We built a microservices architecture using Node.js for core services, PostgreSQL for transactional data, MongoDB for product catalogs, Redis for caching and sessions, and Elasticsearch for search. The entire platform runs on AWS with automatic scaling based on demand.
Performance Improvements
The results exceeded expectations. Search response time dropped from 2.5 seconds to 200ms. Page load time improved by 60%. Payment processing success rate increased to 99.8%. Infrastructure costs decreased by 30% despite 10x transaction volume.
The platform now handles peak loads we couldn't have imagined a year ago, while our AWS bill is actually lower.
Key Lessons
Start with the biggest pain points. We prioritized search because it was the most common complaint. Use managed services where possible—we chose AWS RDS over self-managed databases, saving countless hours. Monitor everything from day one with proper observability tools. Plan for gradual migration, not big-bang rewrites.
Business Impact
The technical improvements enabled dramatic business growth. Gross merchandise value (GMV) increased 12x. Buyer retention improved 45%. Seller satisfaction scores rose from 3.2/5 to 4.7/5. Time-to-market for new features decreased 70%.