Fintech systems that stay fast and stay compliant
Payment systems, ledgers, and compliance infrastructure have tight constraints. Transactions must be correct, auditable, and fast. Regulatory deadlines do not wait for rewrites.
Happi Hacking helps fintech teams design and review backend systems with these constraints built in from the start. The work draws on production experience scaling Klarna's payment infrastructure and advising regulated startups across Europe.
Common engagements include:
- Ledger architecture review and append-only accounting design
- Performance analysis for high-throughput transaction processing
- Compliance infrastructure, audit trails, and cryptographic verification
- Migration planning from monolith to isolated, supervisable services
Resources
- Building Fintech Systems That Stay Fast and Stay Compliant (Code BEAM Berlin 2025 talk and presentation)
- Scale Audit (two-week system analysis with a detailed scaling roadmap)
- Contact us to discuss your system
