Senior Software Engineer (15+ years) Β· Ruby on Rails Β· Distributed Systems Β· AI-powered Product Features
π Berlin, Germany Β· Permanent Resident
π LinkedIn Β·
GitHub Β·
Website
Iβm a Senior / Staff-level Software Engineer with 15+ years of experience building and scaling production systems across FinTech, HealthTech, AI, and developer platforms.
My core strength lies in turning complex data and infrastructure into reliable, user-facing features β from high-throughput financial event processing to LLM-powered, RAG-based AI insights.
Iβve worked in remote-first, high-ownership environments, contributed to core Ruby infrastructure, and mentored engineers globally through Google Summer of Code and community initiatives.
- πΌ Currently: Senior Ruby on Rails Engineer at PAIR Finance (Berlin)
- π Focus areas: backend architecture, performance, AI-assisted workflows
- π± Exploring: LLM systems, RAG architectures, platform reliability
- π¬ Ask me about: Rails internals, PostgreSQL scaling, Sidekiq, TDD, system design
- π« Reach me: LinkedIn is best
- Ruby on Rails (15y) Β· Trailblazer Β· Sidekiq
- REST APIs Β· OpenAPI / Swagger
- LLMs Β· RAG-based AI systems
- Vue.js (3+ years) Β· TypeScript Β· JavaScript
- React Β· Next.js Β· Ember.js
- PostgreSQL (10y, performance & scaling expert) β millions of events/day
- Redis Β· Kafka Β· RabbitMQ
- Docker Β· Kubernetes Β· Nginx
- AWS Β· GCP Β· S3
- TDD expert: RSpec Β· Minitest Β· Capybara Β· Jest
- Clean Architecture Β· SOLID Β· DDD Β· Agile / Scrum
- CI/CD: GitHub Actions Β· CircleCI Β· Buildkite Β· Jenkins
- Designing fault-tolerant, high-throughput backend systems
- Scaling PostgreSQL-backed applications under heavy load
- Building AI-powered product features using LLMs + RAG
- Writing maintainable code with strong test coverage
- Mentoring engineers and leading by technical example
Senior Ruby on Rails Engineer (2022 β Present)
- Led development of RAG-based AI features delivering automated financial insights
- Scaled backend systems handling 2M+ financial events per day
- Built resilient integrations with external payment and financial systems
- Deployed and operated systems using AWS + Kubernetes
Senior Software Engineer
- Designed and implemented high-volume insurance data APIs
- Strong emphasis on clean code, reliability, and TDD
- Author of Ruby gems:
navi_client,unit_validator,examiner - Maintainer of Heroku buildpacks and tooling
- Contributor to Bundler, RubyGems, Bootsnap, Sidekiq, Discourse
- π§βπ« Google Summer of Code (Ruby Org) β Admin & Mentor
- π± Founder of RubyNepal.org β bootcamps, meetups, mentoring
- π Former Instructor at Leapfrog Academy (Rails)
I care deeply about growing engineers, not just shipping code.
- πΌ LinkedIn: https://linkedin.com/in/zoras
- π§βπ» GitHub: https://github.com/zoras
- π£οΈ Twitter (x): https://x.com/zoraslapen
I enjoy building systems that scale β and helping people grow while doing it.




