At Fast Bank, I build the ASP.NET Core backend for a mobile banking app serving 100,000+ active users, including payments, transaction history, account data, and notifications.
I reduced customer-contract retrieval p95 from 1 second to 300 ms by eliminating EF Core N+1 patterns, using projected read models, and redesigning SQL Server indexes. I also improved five high-volume stored procedures by 30%.
I integrate financial and biometric REST APIs with OAuth2/JWT security, retries, circuit breakers, and correlation-ID tracing. I delivered JWT session security and Firebase Cloud Messaging notifications for payment and transaction events.
Previously, I migrated 100,000 MongoDB records to SQL Server with zero reconciliation variance, reduced CMS retrieval latency by 60%, and improved report generation from 12 to 7 minutes. I also mentor developers through code reviews, pairing, clean architecture, and SOLID refactoring.
