Egor Grushin

Designed and implemented a microservice architecture (Auth, User, API Gateway) with RabbitMQ-based communication and Dockerized service isolation. Implemented Saga-based workflows to maintain cross-service consistency and prevent orphaned records on failure. Built JWT authentication with refresh token rotation and RBAC using NestJS guards. Designed PostgreSQL schemas with indexes and Prisma migrations; delivered 10+ REST endpoints with Swagger documentation. Integrated Redis caching (cache-aside, TTL, invalidation), reducing read latency on frequently accessed endpoints by 35–45%.

Built APIs for groups and members with seat limits, age checks, waitlists, schedule-conflict detection, and RBAC. Developed training-cancellation saga: cancel session → refund → notify, with compensation logic for failed steps. Integrated CSV/Excel imports and Google Sheets synchronization with field mapping, deduplication, and cron-based jobs. Applied Redis cache-aside and versioned RabbitMQ message schemas for reliable inter-service communication. Wrote unit and integration tests with Jest and set up automated test runs in CI.

Optimized performance with SSR and React Query (caching, refetch, staleTime), reducing API calls and improving UX. Improved Lighthouse performance score by 35% through React Query caching and SSR data-loading optimizations. Refactored legacy code into reusable modules and collaborated on design reviews, API integration, responsive layout, and deployment workflows.