Hello, I'm

Marek Bytnar

Independent Software Engineer & Technical Lead | Ruby, JavaScript, AI/LLM

Self-directed engineer with 18 years building production systems at scale. Operating independently as a B2B contractor, I've delivered 2,200+ pull requests across 45+ repositories—from legal technology and customer communication platforms to AI/LLM integration using Amazon Bedrock. Expert in autonomous technical leadership, system architecture, and modernization.

About Me

Independent Software Engineer with 18 years building business-critical systems across multiple domains. Operating autonomously as a B2B contractor for AirHelp since 2016, I work self-directed without managerial oversight, delivering 2,200+ merged pull requests across 45+ repositories. Recently designed and deployed production-grade LLM pipelines using Amazon Bedrock (Claude models), implementing cost optimization through prompt caching, concurrency management, and comprehensive observability.

Expert in Ruby on Rails ecosystem with strong full-stack capabilities spanning legal technology (850+ PRs), infrastructure management (295+ PRs), and customer communication platforms (300+ PRs). I independently scope, design, and implement complex features—from IAM security improvements to AI-powered message summarization and real-time notification systems.

Self-directed technical leader who takes full ownership from architecture to implementation. I bridge traditional software engineering with modern AI capabilities, maintaining legacy systems while introducing cutting-edge features. My autonomous work style, combined with deep technical expertise and comprehensive documentation practices, enables me to deliver scalable solutions that balance technical excellence with business pragmatism.

18 Years Experience
2,200+ Pull Requests
45+ Repositories

Experience

Latest Projects

AI-Powered Communication System

Independent Technical Lead & AI Integration Architect

Ruby on Rails, AWS Bedrock (Claude), Langfuse, Kubernetes, PostgreSQL

Self-directed design and implementation of production-grade LLM pipeline processing thousands of messages daily. Built end-to-end system handling message summarization and email classification with autonomous cost optimization (prompt caching, concurrency management), PII safety, and comprehensive monitoring. Independently architected communication data models across microservices.

Legal Technology Platform (Eagle)

Independent Technical Lead & Full-stack Developer

Ruby on Rails, PostgreSQL, Sidekiq, React.js, Docker, Cypress (850+ PRs)

Built comprehensive legal case management system from scratch supporting document generation, workflow automation, and external lawyer integration. Independently architected domain decoupling from company monolith. Led team of ~5 developers while maintaining hands-on technical ownership. Implemented SPA architecture with RESTful API and comprehensive test coverage.

Document Generation System

Independent Backend Architect

Ruby on Rails, ERB, json-schema-form, PostgreSQL

Independently conceptualized and built automated document generation system for pre-legal and legal workflows. Designed flexible schema-driven architecture supporting multi-jurisdiction compliance and dynamic template management.

Customer Support Platform (Cockpit)

Backend Developer & Domain Architect

Ruby on Rails, PostgreSQL, Microfrontends (300+ PRs)

Developed finance and legal functionalities within large monolithic application. Independently architected and executed legal domain decoupling strategy, improving system maintainability and team autonomy. Contributed to microfrontend architecture evolution.

Tripcase (Travel Assistant)

Backend Developer

Ruby on Rails, MariaDB, Backbone.js

Worked on a complex project developed by multiple teams across different locations. Successfully refactored the core part of the application handling trips source data.

Work History

Independent Software Engineer & Technical Lead

AirHelp (B2B Contractor)

2016 - Present (2,200+ PRs across 45+ repositories)

Self-directed technical partner working autonomously without managerial oversight. Full ownership of projects spanning legal technology (850+ PRs), infrastructure management (295+ PRs), customer communication platforms (300+ PRs), and AI/LLM integration. Independent technical decision-making, system architecture, and team enablement through documentation and mentoring.

Senior Software Developer

Sabre Corporation

2014 - 2016

Developed enterprise-grade travel technology solutions. Worked on complex systems handling high-volume transactions for the global travel industry.

Software Developer

Sabre Corporation

2013 - 2014

Backend development and system optimization for travel technology platforms.

Software Developer

Startups (Digital Mines, CloudVertical)

2011 - 2013

Early-stage startup development experience, building products from the ground up in fast-paced environments.

Skills & Technologies

AI & Machine Learning

LLMs (Claude/Bedrock) Langfuse Prompt Engineering AI Agents Cost Optimization

Languages

Ruby JavaScript TypeScript SQL HTML/CSS ERB

Frameworks & Libraries

Ruby on Rails React.js Vite Sidekiq Shoryuken Sinatra

Databases & Storage

PostgreSQL Elasticsearch Redis MariaDB

Infrastructure & DevOps

AWS (SQS, IAM, Bedrock) Kubernetes Docker Terraform GitHub Actions Buildkite

Testing & Quality

RSpec Playwright Cypress Jest TDD/BDD

Architecture & Practices

Microservices Domain-Driven Design RESTful APIs CI/CD Code Review

Soft Skills

Team Leadership Mentoring Technical Communication Product Collaboration

Get in Touch

I'm always interested in hearing about new projects, opportunities, and collaborations. Whether you have a question or just want to say hello, feel free to reach out!