Fintech Microservices
Ensured system stability for high-volume financial operations.
Summary
Chunk Creations contributed to the development of one of Poland's leading online currency exchange platforms, serving thousands of daily transactions in currency conversions. The engagement involved building and maintaining CQRS-based microservices and hybrid React/Angular frontends, ensuring system reliability and performance for high-volume financial operations.
This work required deep understanding of financial domain requirements, strict regulatory compliance, and zero tolerance for system failures in a continuous trading environment.
The Challenge
The client operates one of Poland's largest online currency exchange platforms, where system reliability directly impacts customer trust and business revenue. The platform needed to handle high transaction volumes with real-time rate updates, ensure continuous availability since financial operations cannot afford failures, maintain regulatory compliance with strict financial reporting and audit requirements, support legacy integration as new features must work with the existing Angular codebase, and scale for increasing user base and transaction volumes.
Key Deliverables
CQRS Microservices Architecture
Traditional monolithic architecture could not scale for increasing transaction volumes while maintaining the audit trail required for financial compliance. The engagement developed CQRS-based services with separated read and write operations for optimized performance, event sourcing for complete transaction history and audit compliance, message queues for reliable asynchronous communication, and eventual consistency patterns for distributed operations. The architecture handled significant transaction growth while maintaining complete audit trails.
Hybrid Frontend Development
The platform had an existing Angular codebase, but new features required React's component model. Complete rewrite was not feasible for a continuously operating financial platform. The engagement implemented a hybrid frontend strategy building new features in React with TypeScript, micro-frontend integration with existing Angular modules, shared state management between frameworks, consistent UX across both codebases, and gradual migration path for legacy components — all delivered with zero downtime during transition.
Real-Time Rate Management
Currency exchange rates change constantly. Users need accurate, real-time rates while the system must handle rate volatility appropriately. The engagement built a real-time rate management system with WebSocket connections for instant rate updates, intelligent rate caching and invalidation, rate locking for transaction completion, and historical rate tracking for compliance.
Transaction Processing Pipeline
Financial transactions require complex validation, compliance checks, and multi-step processing while maintaining user experience. The engagement developed a robust transaction pipeline with multi-stage validation, idempotent transaction processing preventing duplicates, rollback mechanisms for failed transactions, and status tracking with user notifications.
Impact
- System uptime maintained at enterprise-grade levels throughout the engagement
- Zero critical production incidents during the tenure
- Substantial transaction volume growth supported without architectural changes
- Complete audit compliance maintained for financial regulations
- Increased user trust through reliable, fast transactions
- Scalable foundation supporting continued business growth
Why This Matters
Building financial software carries unique responsibility. When users trust a platform with their money, system failures are not just bugs — they are breaches of trust with real financial consequences.
This engagement required the discipline necessary for mission-critical systems: comprehensive testing, defensive coding, proactive monitoring, and always having a rollback plan. Working with hybrid Angular/React architecture also demonstrated pragmatic engineering — sometimes the right solution is not a complete rewrite, but thoughtful integration that delivers value while managing risk.