20+ yearsHands-on software engineering
3,000+ req/sTripsta support systems
10+ → 30+Ragnarson company growth
Profile
I’m a hands-on software engineer specializing in Ruby/Rails and Elixir, with more than 20 years in software engineering. I build web products across the stack, from backend systems, APIs and data integrations to user interfaces, testing and deployment.
I combine technical team leadership with implementation: building remote teams, mentoring developers, working directly with international clients and running an independent consultancy. I value TDD, clear business logic and reliable delivery.
My current focus includes LLM-enabled applications and AI-assisted engineering workflows. An MSc in Computational Intelligence gives me a foundation in AI and machine learning; my practical work centers on model APIs, structured outputs, prompt design and evaluation.
Professional experience
Impactpool — Senior Software Developer
Sep 2021–Apr 2026 · Remote
Scope: hands-on backend development and technical team leadership.
- Helped build and lead the distributed engineering team for a Rails 8 platform connecting humanitarian employers with qualified talent.
- Worked on job matching, talent pools and analytics, including BigQuery and external API integrations.
- Developed dynamic interfaces with Hotwire (Turbo and Stimulus) and reusable ViewComponent UI elements.
- Integrated Puppeteer-based web scraping, Dry-rb business logic and Sequel database access.
Belighted — Senior Backend Developer
Oct 2018–Aug 2021 · Remote
- Built the backend for Hannah Online, a financial forecasting application, using Rails, PostgreSQL, GraphQL, Dry-rb and RSpec.
- Developed the backend for AXS, a car-sharing platform with external API and SOAP integrations.
- Built backend functionality for Admeet, a GDPR documentation generator, using Roda, ROM, PostgreSQL and GraphQL.
Ragnarson — Senior Ruby Developer / Co-owner
Developer: Apr 2011–Jun 2016 · Co-owner: Jul 2014–Oct 2016 · Sopot / Remote
- Worked on Tripsta (TravelPlanet) high-performance support systems handling 3,000+ requests/second, using Ruby, Goliath, Sinatra and Redis.
- Built backend systems for Getmii (geo-based messaging APIs for iOS and Android), MaMyMo (Google Ads management), Locafox (location-based price comparison) and Masii (financial product comparison).
- Used Ruby, JRuby, Roda, ROM, Dry-rb, PostgreSQL, Elasticsearch and RSpec; also worked on Rails/Spree e-commerce and ActiveAdmin applications.
- Established the Tricity office and helped grow the company from 10+ to 30+ developers.
- Hired and trained developers, including 100+ interns, and worked directly with clients as Project Manager and Account Manager.
Independent consulting & products
Gotar — Founder / Independent Software Engineer
Apr 2011–present · Gdynia, Poland / Remote
- Run an independent Ruby/Elixir consultancy, building end-to-end web applications and systems for international clients.
- Provide business consulting for Rebased Software House, drawing on experience in engineering, team development and client-facing work.
Rails 8 · Hotwire · Solid Queue · Kamal
- Built a job discovery and application-tracking product with automated collection from public job sources and 4,500+ collected listings.
- The product offers CV-based role matching with visible evidence and geography checks, plus private application notes and status tracking.
LLM applications & engineering workflows
- Build LLM-enabled features and an AI assistant for engineering workflows, working with prompt design, structured outputs, model/API integration and evaluation.
- Use AI-assisted repository research, prototyping and code review alongside established testing and delivery practices.
Technical skills
- Languages & core
- Ruby · Ruby on Rails · Roda · Hanami · Elixir · JavaScript · TypeScript · Node.js
- Web & UI
- React · Hotwire (Turbo, Stimulus) · ViewComponent · HTML/CSS · Tailwind CSS · Figma · Interface design · Design-to-code implementation
- Backend & quality
- Sequel · ROM.rb · dry-rb · REST APIs · GraphQL · SOAP · RSpec · TDD/BDD · Query optimization · Caching
- Data & integration
- PostgreSQL · SQL · NoSQL (MongoDB, Redis) · Elasticsearch · BigQuery · Puppeteer
- Background jobs
- Sidekiq · Active Job · Solid Queue · Scheduling · Retries · Idempotency
- Cloud & delivery
- Linux · Docker · AWS (EC2, S3, RDS, IAM) · CI/CD · GitHub Actions · GitLab CI · Kamal · Git
- Reliability & access
- Monitoring · Sentry · Datadog · Prometheus · Grafana · OpenTelemetry · OAuth/OIDC · RBAC
- AI applications
- LLM integration · Structured outputs · Prompt design · Tool/function calling · Evaluation · RAG · Embeddings/vector search · pgvector · RubyLLM
- AI-assisted delivery
- Repository research · Prototyping · Code review · Engineering workflow automation
Earlier experience
Renault Trucks (Bernard Trucks) — Web Developer / DevOps
Aug 2006–Sep 2010 · Gdynia
Built company websites and internal PHP/SQL applications; built and managed Linux servers.
ITM Centrum Komputerowe — Web Developer / Lecturer
Lecturer: Dec 2005–Jul 2006 · Developer: Apr–Jul 2006 · Gdańsk
Built PHP/SQL websites and taught professional courses, including Linux administration and PHP.
Education
MSc, Computational Intelligence — University of Gdańsk, 2008–2010
AI, machine learning, algorithms and computational methods.
BSc, Computer Science — University of Gdańsk, 2005–2008
Languages
Polish · English
Outside engineering
Martial arts, hiking and mountain biking, photography, cooking, fantasy & sci-fi, and motorcycle travel.
