Oskar Borsuk
I am Oskar Borsuk, a Senior Backend Engineer specializing in Go, with 9+ years building distributed systems, event-driven microservices, and high-throughput APIs.
About
I am Oskar Borsuk, a Senior Backend Engineer specializing in Go, with 9+ years building distributed systems, event-driven microservices, and high-throughput APIs. Go is my primary language for production services, and I also work with Python and Java where they fit best in the stack. I design for operability with clear contracts (gRPC/REST), structured logging, and observability (OpenTelemetry), guided by well-defined SLOs. I routinely operate with Kubernetes, service meshes, and cloud-native tooling on AWS, automating schema changes, canary rollouts, and more to keep systems reliable at scale.
I thrive in collaborative product teams, shaping architecture and coding standards while mentoring engineers on Go idioms, testing strategies, and production readiness. My focus is on maintainability, long-term cost control, and performance profiling to keep p95/p99 latencies in check. I enjoy turning requirements into resilient backends, driving operability-first design, and partnering with data and product teams to ship features safely and efficiently.
- 9 years' experience
- Joined January 2026
Languages
- EnglishFluent
Industry experience
- Software & Internet
- Professional Services
Work experience
Led the design and implementation of Go microservices on Kubernetes (AWS EKS), exposing public REST APIs via gRPC-Gateway and internal contracts via Protobuf. Built an event-driven architecture around Kafka with outbox patterns and exactly-once processing, modeled and tuned multi-tenant PostgreSQL schemas, introduced OpenTelemetry with consistent correlation IDs, implemented robust authentication (OIDC, mTLS) and edge/service RBAC, delivered zero-downtime migrations with dual-write/dual-read, drove performance profiling and memory optimizations, and built CI/CD pipelines (GitHub Actions + Argo CD) with policy checks and canary deployments. Published protobufs and Pact contracts and mentored 7 engineers.
Built Go-based indexers and ingestion services for Ethereum-compatible chains and Bitcoin, normalizing blocks, transactions, and logs into PostgreSQL/ClickHouse with reorg-resilience. Exposed internal gRPC services for wallet and balance queries, implemented queue-backed workers for confirmations and on-chain monitoring with at-least-once delivery, hardened custody flows with HSM/KMS integrations and auditable actions, and delivered reconciliation jobs in Python to ensure ledger parity.
Shipped production APIs in Java (Spring Boot) and Node.js, introduced Go for latency-sensitive components, designed RESTful services with careful transaction boundaries, built real-time features with WebSockets, established CI/CD pipelines, and implemented comprehensive testing. Led monolith-to-microservices migration with centralized config and service discovery, and authored Python utilities for data migrations and runbooks.
Education
Hire Oskar Borsuk today
Post a job and invite Oskar, or contact them directly. No hidden commission.