Boris Finkelshteyn

Led end-to-end backend development for a highly scalable chat backend, achieving sub-50 ms response times. Designed and implemented a microservice-based architecture with a focus on scalability, resilience, and maintainability. Managed the full lifecycle from architectural design to CI/CD, deployment, and production monitoring. Refactored the codebase to reduce size, improve modularity, and simplify migration to gRPC. Migrated infrastructure from VMs to Kubernetes with full automation via Terraform and ArgoCD, enabling unlimited environments with a single command. Built and maintained CI/CD pipelines with GitLab CI/CD and ArgoCD, deployed self-hosted Grafana for observability, and performed in-depth profiling to resolve bottlenecks. Addressed asynchronous and eventual-consistency challenges in a distributed backend. Implemented an MCP server to connect the backend API with an LLM, adding AI-powered chat capabilities.

Designed and delivered a multi-tenant Authorization Server with OAuth2 support, including federated OAuth2 and SAML. Built MVP with Spring Boot, OAuth2/OpenAPI tooling, and security auditing. Implemented an Integration Engine based on the runners concept, enabling user-run code inside a user environment via server (Java Spring Boot, MySQL) and a runner (Java, GraalVM) connected through WebSocket. Ensured proxy-enabled, secure WebSocket connections, editor API, encrypted script transfer, scheduled execution, and horizontally scalable runners. Technologies used included Java 7/8, Spring Boot, Lombok, Liquibase, JUnit, Testcontainers, Maven, OAuth2, MySQL, Docker, AWS, and OpenAPI.

Developed a new reactive backend for a social media application to replace an older async backend based on Javalin and CompletableFuture. Built a Java 11-based stack with Spring WebFlux, covering feature development, bug fixes, unit and E2E tests, and cloud configuration. Implemented CI/CD using AWS CodePipeline with Fargate and conducted code reviews to maintain high quality.