Hi 👋, I'm Saroj Maharjan

Senior Software Engineer (15+ years) · Ruby on Rails · Distributed Systems · AI-powered Product Features

📍 Berlin, Germany · Permanent Resident
🔗 LinkedIn · GitHub · Website

🚀 About Me

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

🛠️ Tech Stack (Production Experience)

Backend & Platforms

• Ruby on Rails (15y) · Trailblazer · Sidekiq
• REST APIs · OpenAPI / Swagger
• LLMs · RAG-based AI systems

Frontend

• Vue.js (3+ years) · TypeScript · JavaScript
• React · Next.js · Ember.js

Data & Infrastructure

• PostgreSQL (10y, performance & scaling expert) — millions of events/day
• Redis · Kafka · RabbitMQ
• Docker · Kubernetes · Nginx
• AWS · GCP · S3

Testing & Engineering Practices

• TDD expert: RSpec · Minitest · Capybara · Jest
• Clean Architecture · SOLID · DDD · Agile / Scrum
• CI/CD: GitHub Actions · CircleCI · Buildkite · Jenkins

🧠 What I’m Known For

• 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

⭐ Selected Work & Impact

🏦 PAIR Finance (FinTech, Berlin)

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

🏥 Vericred (HealthTech, API Platform)

Senior Software Engineer

• Designed and implemented high-volume insurance data APIs
• Strong emphasis on clean code, reliability, and TDD

🧑‍💻 Open Source & Infrastructure

• Author of Ruby gems: navi_client, unit_validator, examiner
• Maintainer of Heroku buildpacks and tooling
• Contributor to Bundler, RubyGems, Bootsnap, Sidekiq, Discourse

🌍 Community & Leadership

• 🧑‍🏫 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.

📫 Let’s Connect

• 💼 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.