Mateusz Świszcz - Full-Stack Software Engineer

Hey, I'm Mateusz.

Full-stack engineer based in Krakow.

I build robust, scalable Ruby on Rails SaaS applications and AI-powered solutions. With 12 years of professional experience, I specialize in crafting maintainable, well-structured code that stands the test of time.

Quality over speed, but I know how to balance both. Self-disciplined remote worker for 6+ years, I bring deep software architecture knowledge to every project I touch.

Let's work together

Senior engineer, 12+ years

Shipping production web applications since 2013.

Full-stack development

Creating applications from end to end - backend and frontend.

Polyglot programmer

Primary expertise is Ruby and Typescript, I use C#, Rust and Python as well

AI & LangChain

Building LLM-powered features with LangChain & LangGraph.

Formal education

Engineer's degree in Information Technology from the University of Silesia in Katowice.

End-to-end ownership

Takes features from discovery to long-term maintenance.

Remote-first collaborator

6+ years async remote work with international teams.

Leadership & mentoring

Leads teams and mentors developers.

Experience

OMR

Lead Engineer / Software Architect

5+ years (May 2021 - Present)

Hamburg, Germany - Remotely

Lead Engineer and Software Architect on the MyOMR and Reviews platforms, working with Ruby on Rails, TypeScript, GraphQL, LangChain, LangGraph, Neo4j and vector databases.

Key Projects

Team Leadership & Product Delivery

Lead a small agile team delivering user-facing capabilities end-to-end, including the AI Software Advisor, Smart Features, a new authentication system and the Survey Flow.

AI Assistant

Lead development of the Reviews AI assistant using LangChain, LangGraph, Neo4j and vector databases. Covers semantic search, vector databases, LLMs, semantic caching, knowledge graphs, RAG pipelines, and more.

Reviews Platform

Build and evolve the Reviews platform with Ruby on Rails, GraphQL and TypeScript, shipping core platform features including survey response processing, Elasticsearch-powered search and more.

System Architecture

As part of the architecture team, I design and maintain a robust, scalable and maintainable system architecture for the platform.

AKRA Polska

Development Team Lead

1.5+ years (Sep 2019 - Jun 2021)

Kraków, Poland

As a contractor, I've been responsible for managing teams, designing software architecture and developing applications for companies such as XING, YND, Solaris, MGIS, Paypal. Main expertise: Ruby & Ruby on Rails. Programming languages: Ruby, Rust, Java, JavaScript, C#. Frameworks: Ruby on Rails, React.js, Tokio. Tools: GraphQL, Docker, ElasticSearch, JIRA, Git.

Key Projects

Senior Ruby Developer @ Munich General Insurance Services

Rebuilt API application for Insurance Services: rewrote SQL-based system to Ruby on Rails with GraphQL API. Designed architecture for the new application and developed backwards compatible API. Tools: Ruby, Ruby on Rails, GraphQL, Docker, SQL, Bitbucket, JIRA, Git.

Senior Ruby and Rust Developer @ PayPal

Senior Ruby and Rust Developer at PayPal. Built and maintained new payment processing system for PayPal using Rust, Java and Ruby.

Senior Ruby Developer @ YND

Fintech startup in Ruby on Rails. Created and maintained web application for seamless online instant payments. Implemented fraud prevention services, payment processing, administration panel, and web applications for customers and merchants. Tools: Ruby, Ruby on Rails, React.js, Redux, Node.js, Docker, Kubernetes, ElasticSearch, Sidekiq, DataDog, Redis.

Allani

Ruby on Rails Developer

9 months (Jan 2019 - Sep 2019)

Kraków, Poland

Full stack web developer in Ruby on Rails and React.js. Tools: Ruby, Ruby on Rails, Kafka, PostgreSQL.

Key Projects

E-commerce Search & A/B Testing

Implemented A/B testing tools and administration panel for a major e-commerce search engine. Built features using Ruby on Rails and React.js.

Micro-service Architecture

Learnt and implemented micro-service oriented architecture using Kafka for event-driven communication between services.

AKRA Polska

Ruby on Rails Developer @ XING

2.5+ years (Mar 2016 - Dec 2018)

Kraków, Poland

Full-Stack Web Developer for one of the biggest social networks. Back-end in Ruby on Rails and front-end in React & Redux. Technologies: Ruby, Rails, RSpec, DelayedJob, React & Redux, SASS, CoffeeScript, ElasticSearch, Docker, AMQP, PostgreSQL, Jenkins, Git.

Key Projects

Profile Sync & GDPR

Implemented profile synchronization across platform and GDPR-compliant profile data export mechanism.

Search & Matching

Built searching algorithms using Elasticsearch and matching algorithms for the social platform.

API Architecture

Introduced service-oriented approach and endpoint layer architecture with custom serializers for JSON:API implementation.

Continuous Integration & Deployment

Introduced bug-tracking, monitoring and deployment automation.

Selleo

Web Developer

1.5+ years (Feb 2014 - Sep 2015)

Bielsko-Biała, Poland

As a ruby developer, working for company clients, mainly startups and some long-term projects. During that time I've learned to develop professional web applications in Ruby and how to create lasting architecture for stable software.

Skills

Core competencies

Full stack development

Software architecture

Database design

API design

Codebase optimization

Prompt engineering

Building Agentic applications

Project Tech leadership

Infrastructure setup

Testing & quality

Languages

Ruby

JavaScript

TypeScript

Python

Rust

Frameworks

Ruby on Rails

ReactJS

LangChain + LangGraph

GraphQL

Databases & Search

MySQL / PostgreSQL

Redis

Elasticsearch

Vector Databases

Neo4j

DevOps & Cloud

Git

Docker

Google Cloud

Linux

Other

Unity

Claude

Contact

hello@swiszcz.pl

GitHub

@mswiszcz

/in/swiszcz