Pawel Budnik

Senior Full Stack Engineer

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Warsaw, Poland

Experience

Sep 2020 - Present
5 years 5 months
United States

Senior Full Stack Engineer

Peritus Inc

  • Designed and delivered a backend core platform end-to-end, owning architecture, API design, data modeling, implementation, and production rollout for a business-critical system.
  • Built the primary backend using Ruby on Rails as the orchestration layer, defining API-first contracts, validation rules, versioning, and partner-facing interfaces.
  • Incrementally evolved the system by extracting high-throughput and latency-sensitive components into Go services, avoiding risky rewrites while improving scalability.
  • Designed domain boundaries and service ownership, enabling a controlled transition from a tightly coupled Rails monolith toward a more distributed architecture.
  • Implemented event-driven workflows (messaging, retries, idempotency) to decouple provisioning logic and reduce cross-service failures by ~42%.
  • Introduced Redis caching and asynchronous processing, improving p95 latency by ~33% under real production traffic.
  • Embedded observability by default—structured logs, metrics, and tracing—reducing MTTD by ~58% and MTTR by ~40%.
  • Achieved and sustained 99.95% availability while continuously shipping new backend features and integrations.
  • Designed secure authentication and authorization flows (tokens, scopes, rate limits), supporting external partners and internal services safely.
  • Used TypeScript to build internal admin tools and operational dashboards that improved support and incident response workflows.
  • Contributed small concurrent components in Elixir for specific background and message-processing use cases where lightweight concurrency was beneficial.
  • actively participated in incident response, post-mortems, and reliability improvements, using production data to drive architectural decisions.
  • Mentored engineers and promoted a strong ownership culture, emphasizing pragmatic decision-making, clean APIs, and production responsibility.
Apr 2017 - Jun 2020
3 years 3 months
United Kingdom

Full Stack Developer

Make IT Happen

  • Developed and maintained backend APIs and services supporting customer-facing products with 99.9% uptime.
  • Contributed to monolith refactoring efforts, improving modularity and internal ownership boundaries.
  • Delivered new product features from idea to production in close collaboration with product teams.
  • Implemented event-driven data flows using Kafka and CDC pipelines.
  • Strengthened platform security with OAuth2/JWT and token lifecycle management.
  • Improved system reliability through monitoring, alerting, and SLO tracking.
  • Participated in on-call rotations and incident response, reducing recurring incidents.
  • Improved backend performance through query optimization and caching strategies.
  • Supported CI/CD adoption and testing practices to increase deployment confidence.
Aug 2011 - Jun 2015
3 years 11 months
Singapore

Back End Developer

Avensys Consulting

  • Built high-throughput backend APIs in Java for transactional systems.
  • Optimized PostgreSQL schemas and queries, reducing p95 latency by ~29%.
  • Introduced Redis caching and rate limiting to stabilize peak traffic.
  • Automated build and deployment pipelines to improve release reliability.
  • Added monitoring and alerting to production systems.
  • Supported incident investigation and operational improvements.
  • Improved API stability through versioning and contract discipline.

Summary

Senior Software Engineer with 10+ years of experience building backend platforms in SaaS and regulated domains, specializing in Ruby on Rails and Go. I focus on API design, distributed systems, and monolith-to-services evolution, owning problems end to end while balancing speed, quality, and business impact.

Skills

  • Backend: Ruby On Rails, Go, Java (Spring Boot), Python (Fastapi/django), Elixir (Basic, Concurrency-focused Services), Node.js (Nestjs), Rest/graphql/grpc, Oauth2/jwt, Kafka, Redis, Cqrs, Api Standards.
  • Frontend: React/next.js, Angular, Typescript, State Management, Ssr/spa, Accessibility (Wcag), Core Web Vitals Tuning.
  • Ai & Data: Rag/langchain Integration, Embeddings And Vector Stores (Pgvector/pinecone), Etl/elt, Airflow, Analytics Events, Evaluation Sets.
  • Database: Postgresql, Mysql, Mongodb, Redis; Indexing/tuning, Migrations, Cdc, Read Replicas, P95 Query Slas.
  • Devops & Tools: Docker, Kubernetes, Terraform, Github Actions/jenkins, Helm, Nginx, Cdn, Secrets Management, Prometheus/grafana/datadog, Opentelemetry.
  • Testing & Quality: Junit/pytest/jest/cypress, Contract Tests, Testcontainers, Sast/dast, Mutation Tests, >90% Critical-path Coverage.

Languages

English
Advanced

Education

Aug 2011 - Jun 2015

Nanyang Technological University

Bachelor’s Degree in Computer Science · Computer Science · Singapore

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