At Credit Bank of Moscow (MKB) / ITQ Group, I engineered .NET 8 microservices for payment processing, refunds, integrations, and operational reconciliation. I implemented payment idempotency and webhook validation to prevent duplicate charges.
I designed refund APIs using PostgreSQL row-level locks to protect against over-refunding. I also reduced reconciliation time for 30,000 records from 11 minutes to 2 minutes 40 seconds through SQL/Dapper batching and composite indexing.
At Auchan Retail Russia / ICL Services, I developed backend checkout services for the ICL.Retail platform and worked on checkout APIs, offline data sync, and retry queues. I implemented RabbitMQ deduplication and sequence versioning to protect message state.
I reduced monthly sales report execution time from 18 seconds to 4 seconds across 5M dataset rows, and lowered product catalog API p95 response time from 260ms to 70ms with Redis caching.
