Mateusz Bielec
Verified Expert in Engineering
Software Developer
Rzeszow, Poland
Toptal member since November 25, 2024
Mateusz is a detail-oriented software developer who specializes in Ruby back ends. He has 10+ years of experience resolving complex domain problems in legacy systems, including fintech, hiring, and recycling industries. Devoted to code review, he advocates for best practices to mitigate business risks and promote a higher-quality codebase. Mateusz has a solid record of improving project maintainability and developer experience in large-scale organizations.
Portfolio
Experience
- Ruby on Rails (RoR) - 14 years
- Ruby - 14 years
- Code Review - 13 years
- Complex Problem Solving - 13 years
- PostgreSQL - 12 years
- Agile - 11 years
- Team Mentoring - 10 years
- GitHub Actions - 5 years
Preferred Environment
Ruby, Ruby on Rails (RoR), PostgreSQL, GitHub Actions
The most amazing...
...thing I've done is reviving an unmaintained crucial internal application used by hundreds of developers without prior experience in Node.js.
Work Experience
Senior Back-end Engineer
Toptal
- Worked on a Ruby service with 1+ million lines of code and managed 15+ repositories, including internal and open-source gems, tools, and supporting apps. Improved the development experience for hundreds of engineers.
- Removed the risk of breaking a deployment orchestrator used by 100+ applications by identifying an issue with an outdated Slack integration in Node.js and planning the migration to the up-to-date framework.
- Participated in a rotational consulting duty to support feature teams using internal libraries and tools. Assisted with debugging and environment setup. Guided daily tasks while maintaining a high SLA for resolved support requests.
- Improved maintainability of the deployment orchestrator application by upgrading it to the newest Node.js version and introducing a testing layer. This reduced the number of bugs and increased confidence among other developers.
- Implemented a shared GitHub Action powered by a Ruby script to support gathering comprehensive, technology-agnostic code statistics for 100+ repositories inside the organization.
Senior Ruby Developer
Ironin
- Integrated the application with external tax provider services to calculate tax amounts based on the current tax rates and store tax documents for tax compliance purposes.
- Created a message logger to store custom events and logs on different storages like Elasticsearch via adapter pattern.
- Implemented an automated mechanism for splitting requested amounts for scheduled payments based on payment type.
Software Developer
PGS Software
- Collaborated with the stakeholders daily by gathering the requirements and showcasing key functionalities.
- Participated in and then led the Ruby ERP app development with a mobile client for nine months. Scaled a data synchronization REST API.
- Mentored interns and organized internal Ruby workshops.
Software Developer
SoftSystem
- Managed database migrations in Java-based applications.
- Provided technical support and handled incoming incidents.
- Diagnosed and resolved a wide range of technical issues.
Experience
Outdated Slack Intergration Migration
Education
Master's Degree in Computer Science
Rzeszow University of Technology - Rzeszow, Poland
Skills
Libraries/APIs
Sidekiq, jQuery, REST APIs, Node.js
Tools
RSpec
Languages
Ruby, GraphQL, TypeScript, Java, C#
Frameworks
Ruby on Rails (RoR), Bootstrap, AngularJS
Paradigms
REST, Agile
Platforms
Docker, Heroku
Storage
PostgreSQL, Datadog, Elasticsearch, PL/SQL
Other
Code Review, Team Mentoring, GitHub Actions, Complex Problem Solving, DevExpress, Enterprise Service Bus (ESB), Planning, Estimations, Risk Assessment, Software Development
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