The challenge
eifas, an all-in-one fintech SaaS for small and medium businesses, handled real-time bookkeeping, OCR document processing, payroll, and debt collection — on an aging AngularJS stack. The platform had to be modernized while serving paying customers daily:
- Migrating the frontend from AngularJS to React with no service interruption
- Preserving critical financial workflows: bookkeeping, payroll, collections
- Integrations with banking APIs, payment gateways, and OCR services
- Raising test coverage and code quality on a codebase in active use
- Compliance with data protection regulations throughout
The approach
I joined as team lead, embedded with the internal team, and ran the modernization end to end.
Team leadership
- Led the developer team through the migration strategy, ticket by ticket
- Established code review processes and quality standards
- Significantly increased test coverage across the platform
- Coached the team on the new stack and best practices
Architecture & delivery
- Re-architected core subsystems for performance and scalability
- Migrated the frontend to React while shipping new features in parallel
- Built new REST APIs and integrated OCR, banking, and payment services
- Optimized database queries and Sidekiq background processing
DevOps & security
- Automated deployment pipelines and AWS infrastructure provisioning
- Cut deployment times with a streamlined release process
- Monitoring, alerting, and high security standards across the cycle
The results
- Full migration from legacy AngularJS to a modern React and Rails stack
- 100% service uptime during the entire modernization
- Substantially higher test coverage and code quality
- Faster deployments through CI/CD automation
- Platform extended with new banking and OCR integrations along the way
Stack
- Ruby on Rails
- React
- PostgreSQL
- Sidekiq
- AWS
- OCR APIs
- Banking APIs
The cooperation with Andrej and the team was always characterized by the highest professionalism.
Matthias Nebur
Product Manager, eifas GmbH