Senior Software Engineer (15+ years) · Ruby on Rails · Distributed Systems · AI-powered Product Features
📍 Berlin, Germany · Permanent Resident
🔗 LinkedIn ·
GitHub ·
Website
I’m 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 — from high-throughput financial event processing to LLM-powered, RAG-based AI insights.
I’ve worked in remote-first, high-ownership environments, contributed to core Ruby infrastructure, and mentored engineers globally through Google Summer of Code and community initiatives.
- 💼 Currently: Senior Ruby on Rails Engineer at PAIR Finance (Berlin)
- 🔭 Focus areas: backend architecture, performance, AI-assisted workflows
- 🌱 Exploring: LLM systems, RAG architectures, platform reliability
- 💬 Ask me about: Rails internals, PostgreSQL scaling, Sidekiq, TDD, system design
- 📫 Reach me: LinkedIn is best
- Ruby on Rails (15y) · Trailblazer · Sidekiq
- REST APIs · OpenAPI / Swagger
- LLMs · RAG-based AI systems
- Vue.js (3+ years) · TypeScript · JavaScript
- React · Next.js · Ember.js
- PostgreSQL (10y, performance & scaling expert) — millions of events/day
- Redis · Kafka · RabbitMQ
- Docker · Kubernetes · Nginx
- AWS · GCP · S3
- TDD expert: RSpec · Minitest · Capybara · Jest
- Clean Architecture · SOLID · DDD · Agile / Scrum
- CI/CD: GitHub Actions · CircleCI · Buildkite · 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 – 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
- 🧑🏫 Google Summer of Code (Ruby Org) — Admin & Mentor
- 🌱 Founder of RubyNepal.org — bootcamps, meetups, mentoring
- 🎓 Former Instructor at Leapfrog Academy (Rails)
I care deeply about growing engineers, not just shipping code.
- 💼 LinkedIn: https://linkedin.com/in/zoras
- 🧑💻 GitHub: https://github.com/zoras
- 🗣️ Twitter (x): https://x.com/zoraslapen
I enjoy building systems that scale — and helping people grow while doing it.