Marek Pawlak
Senior Software Engineer
Experience
Senior Software Engineer
SoftwareMill
- Designed and implemented Ruby-based backend services using object-oriented and idiomatic Ruby practices to support scalable business platforms, resulting in stable and maintainable codebases
- Reviewed and refactored legacy Ruby applications using metaprogramming techniques to reduce duplication and improve extensibility across multiple domains
- Led code reviews focused on identifying code smells, anti-patterns, and test gaps in Ruby and mixed-language repositories, improving overall code quality standards
- Developed automated test suites with RSpec and Minitest integrated into CI pipelines, ensuring consistent verification of business logic before releases
- Built CI/CD workflows using GitHub Actions and GitLab CI to automate testing, static analysis, and deployment validation
- Implemented Docker-based development and testing environments to ensure reproducibility across engineering teams
- Collaborated with cross-functional teams to define coding guidelines and quality benchmarks for backend Ruby services
- Actively contributed production code while mentoring senior and mid-level engineers on Ruby best practices and maintainable design
- analyzed production defects using profiling and debugging tools to identify root causes and document technical debt
- Produced high-quality technical documentation describing system behavior, test coverage, and known limitations
- Worked with Python and TypeScript components alongside Ruby services to support multi-language system integration
- Participated in experimental projects involving AI-assisted development, including prompt evaluation and automated code generation validation
- Evaluated model-generated Ruby code for correctness, performance, and stylistic alignment with idiomatic standards
- Adapted internal engineering guidelines to new domains and evolving technical requirements
- Supported asynchronous collaboration workflows through clear written communication and structured documentation
Full-Stack Engineer
CMC Global Company Limited
- Developed Ruby-based backend features for business applications using clean object-oriented design and modular architecture
- Implemented RESTful APIs and background processing logic while maintaining high test coverage through automated tests
- Performed systematic code reviews to identify defects, refactoring opportunities, and missing test scenarios
- Integrated Ruby applications into CI environments using Jenkins and GitLab CI for automated testing and validation
- Built and maintained Docker images to standardize development and deployment environments
- Collaborated with QA teams to document defects, reproduce issues, and verify fixes in Ruby codebases
- Improved application reliability by profiling Ruby services and optimizing performance bottlenecks
- Wrote clear technical documentation for backend components, test strategies, and known technical constraints
- Contributed to frontend features using JavaScript and TypeScript to support full-stack delivery
- Maintained version control workflows using Git, including branching, rebasing, and conflict resolution
- Assisted in onboarding engineers by explaining Ruby conventions, testing practices, and debugging techniques
- Participated in internal hackathon-style initiatives focused on rapid prototyping and problem-solving
- Supported multi-project environments requiring quick context switching and guideline adaptation
- Ensured Linux-based deployment scripts and automation tasks were reliable and well-documented
- Collaborated closely with technical leads to align implementation details with architectural direction
Frontend Web Developer
TMA Solutions
- Developed and maintained web applications while collaborating closely with backend Ruby and Java services
- Reviewed frontend and integration code to ensure consistency with backend APIs and data contracts
- Assisted backend teams by debugging Ruby-related integration issues from the client perspective
- Used Git-based workflows to manage feature development and bug fixes across shared repositories
- Documented defects and implementation details to support long-term maintainability
- Worked in Linux environments using CLI tools for development, testing, and troubleshooting
- Collaborated with designers and backend engineers to translate requirements into working features
- Contributed to improving development guidelines and internal documentation practices
Industries Experience
See where this freelancer has spent most of their professional time. Longer bars indicate deeper hands-on experience, while shorter ones reflect targeted or project-based work.
Experienced in Information Technology (14.5 years).
Business Areas Experience
The graph below provides a cumulative view of the freelancer's experience across multiple business areas, calculated from completed and active engagements. It highlights the areas where the freelancer has most frequently contributed to planning, execution, and delivery of business outcomes.
Experienced in Information Technology (14.5 years) and Product Development (7 years).
Summary
I’m a Senior Software Engineer with over 13 years of professional experience building, reviewing, and maintaining production-grade software systems across backend, frontend, and full-stack domains. I have a strong background in Ruby development, object-oriented design, code quality analysis, and test-driven development, combined with hands-on experience in CI/CD pipelines, containerized environments, and multi-language ecosystems. I’m highly comfortable working with complex guidelines, evaluating and generating code, reviewing large codebases, and collaborating on experimental and AI-driven initiatives that require precision, adaptability, and deep technical judgment.
Skills
Languages: Ruby, Python, Javascript, Typescript, Sql, Bash
Ruby Expertise: Object-oriented Programming, Metaprogramming, Idiomatic Ruby, Refactoring, Code Smells, Anti-patterns
Testing & Quality: Rspec, Minitest, Test Coverage Analysis, Test Automation, Ci-integrated Testing
Ci/cd & Devops: Github Actions, Gitlab Ci, Jenkins, Docker, Linux Cli, Automated Deployments
Ai & Llm Workflows: Code Generation, Prompt Evaluation, Model-assisted Coding, Benchmarking, Data Annotation
Architecture: Modular Design, Service-oriented Systems, Event-driven Patterns, Maintainability
Tooling: Git, Profilers, Debuggers, Linters, Static Analysis Tools
Documentation: Technical Documentation, Defect Reports, Test Plans, Technical Debt Tracking
Languages
Education
Vietnam National University, Hanoi
Bachelor's degree, Computer Science · Computer Science · Hanoi, Viet Nam
Profile
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