Rafal Mrozik

Senior Full Stack Engineer

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Kraków, Poland

Experience

Apr 2024 - Present
1 year 10 months

Senior Full Stack Engineer

SoftXPro

  • Performed in-depth code reviews across Ruby and multi-language codebases, identifying code smells, anti-patterns, and architectural risks
  • Refactored object-oriented Ruby modules to improve readability, testability, and long-term maintainability
  • Designed and reviewed automated test suites using RSpec, closing coverage gaps and improving defect detection
  • Documented defects, edge cases, and technical debt in a structured, reproducible manner
  • Collaborated with engineers and stakeholders to clarify ambiguous requirements and translate them into precise implementation guidelines
  • Worked in Linux-based environments using Git-centric workflows for iterative review and experimentation
  • Integrated test execution into CI/CD pipelines, increasing confidence in automated quality checks
  • Supported experimental development efforts requiring rapid context switching across tasks and domains
  • Reviewed and validated AI-assisted code suggestions, providing corrective feedback and improvements
  • Maintained high engineering standards while operating under evolving guidelines
Feb 2021 - Jul 2021
6 months

Backend Developer

Datarockets

  • Developed and reviewed backend services with a strong focus on clean Ruby code and object-oriented design
  • Identified performance bottlenecks and logic defects through profiling and targeted debugging
  • Improved test reliability by refactoring brittle test cases and adding missing coverage
  • Participated in peer code reviews emphasizing idiomatic Ruby and long-term maintainability
  • Supported CI/CD pipelines by stabilizing failing test suites
  • Documented bugs and fixes clearly for future reference
  • Collaborated with cross-functional teams on complex technical issues
  • Maintained containerized development environments using Docker
  • Worked extensively with Git-based version control workflows
  • Strengthened overall code quality through incremental improvements
Apr 2020 - May 2021
1 year 2 months

Frontend Manager

Vinova

  • Led code review practices across teams, focusing on readability, correctness, and consistency
  • Established shared guidelines for reviewing and improving complex codebases
  • Balanced delivery speed with sustainable code quality
  • Mentored engineers on identifying anti-patterns and improving design choices
  • Coordinated technical feedback loops across multiple projects
  • Ensured documentation standards were met for features and fixes
  • Supported cross-team collaboration on experimental initiatives
  • Reviewed pull requests spanning multiple programming languages
  • Improved overall engineering discipline and review culture
  • Encouraged thoughtful, evidence-based technical discussions
May 2017 - Apr 2020
3 years

Frontend Web Developer

Vinova

  • Built and maintained production code while participating heavily in peer reviews
  • Improved existing codebases through refactoring and test additions
  • Documented bugs, edge cases, and behavior changes
  • Collaborated with teammates on resolving complex technical issues
  • Worked across JavaScript and backend-adjacent codebases
  • Strengthened understanding of multi-language systems
  • Supported CI pipelines and automated testing
  • Participated in Agile ceremonies and retrospectives
  • Improved code readability and consistency
  • Developed strong habits around careful code analysis
Mar 2015 - Apr 2017
2 years 2 months

Junior Frontend Developer

HMI Managed Healthcare

  • Contributed to regulated codebases requiring high correctness standards
  • Fixed defects and improved code quality under supervision
  • Learned disciplined debugging and documentation practices
  • Participated in code reviews and quality discussions
  • Worked in Linux-based development environments
  • Built foundational skills in structured programming
  • Assisted with testing and validation efforts
  • Developed attention to detail in production systems
  • Supported incremental, low-risk improvements
  • Built strong fundamentals in software craftsmanship

Summary

I'm a Senior Software Engineer with over 10 years of professional experience and a strong background in Ruby, object-oriented design, and multi-language systems. I specialize in writing, reviewing, and improving high-quality code, identifying edge cases and anti-patterns, and translating complex requirements into precise technical solutions. I enjoy working at the intersection of software engineering and AI, contributing my domain expertise to train, evaluate, and improve large language models through rigorous code analysis, experimentation, and documentation.

Skills

  • Languages: Ruby, Python, Javascript, Typescript, Sql
  • Ruby Expertise: Object-oriented Design, Metaprogramming, Idiomatic Ruby, Refactoring
  • Code Quality: Code Review, Static Analysis, Debugging, Profiling, Anti-pattern Detection
  • Testing: Rspec, Minitest, Test Coverage Analysis, Ci/cd Test Integration
  • Ai & Llm Workflows: Prompt Evaluation, Code Annotation, Model Training & Benchmarking
  • Devops & Tooling: Git, Linux Cli, Docker, Github Actions, Gitlab Ci
  • Documentation: Technical Documentation, Defect Reports, Test & Debt Documentation
  • Practices: Context Switching, Guideline Adaptation, Experimental & Research-oriented Work

Languages

English
Advanced

Education

Aug 2010 - May 2014

Nanyang Technological University

Bachelor's degree · Computer Science · Singapore

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