Jack Tomaszewski
Full Stack Developer at fullstackhouse
Greater Poland Voivodeship
Summary
🤩
Rockstar🎓
Top SchoolJack Tomaszewski is a seasoned full-stack developer and technical lead with over a decade of hands-on experience delivering web and mobile applications across startups and large-scale platforms. He has led migrations of legacy systems to modern Node.js/React architectures, built cross-platform apps with React Native, and modernized a 20-year-old healthcare SaaS using a strangler-fig approach while keeping services running. Comfortable across JS/TS, Elixir and Ruby, he contributes to notable open-source projects (MikroORM, Searchkick, ngx-datatable) and has improved core behaviors like transactional handlers, indexing logic, and dataloader ordering. Jack blends engineering leadership—recruiting, mentoring, and establishing CI/CD and IaC practices—with practical product collaboration, having worked closely with product owners, designers and enterprise clients. He’s an advocate of strongly typed and functional styles but pragmatically adopts low-code and AI-assisted tooling to accelerate delivery. Outside day-to-day work he co-organizes meetups, speaks at events and writes about engineering practices, reflecting a continual focus on community and knowledge-sharing.
12 years of coding experience
15 years of employment as a software developer
Bachelor of Science (unfinished) Computer Science, Bachelor of Science (unfinished) Computer Science at Poznan University of Technology
Polish, English, Spanish, Russian
Stackoverflow
1,103reputation
756kreached
17answers
2questions
Github Skills (54)
ruby-rails10
javascript10
twitter-bootstrap10
coffeescript10
entity-manager10
testing10
amazon-elasticsearch10
databases10
entity-model10
typescript10
formtastic10
rails10
websocket10
datatable10
ruby10
Programming languages (22)
Github contributions (5)
mjbellantoni/formtastic-bootstrap
Feb 2014 - Feb 2015
Formtastic form builder to generate Twitter Bootstrap-friendly markup.
Role in this project:
Full-stack Developer
Full-stack DeveloperContributions:19 commits, 5 PRs, 5 pushes in 1 year
Contributions summary:Jack primarily focused on enhancing the `formtastic-bootstrap` library by implementing new features and fixing bugs. They refactored time input components to improve grid layout and styling for Bootstrap integration. Furthermore, they added functionalities like inline options for radio and check boxes. The user also addressed presentation concerns and included changes related to the visual appearance of the form's elements.
form-builderbuildermarkuptwitterbootstrap
mikro-orm/mikro-orm
Jun 2024 - Feb 2025
TypeScript ORM for Node.js based on Data Mapper, Unit of Work and Identity Map patterns. Supports MongoDB, MySQL, MariaDB, MS SQL Server, PostgreSQL and SQLite/libSQL databases.
Role in this project:Back-end Developer
Back-end DeveloperContributions:1 review, 6 PRs, 7 comments in 8 months
Contributions summary:Jack contributed to the MikroORM project by addressing several key areas within the ORM framework. Their work includes fixing a TypeScript error related to synchronous transactional handlers, improving the seeder functionality by making the `Factory.em` protected, adding index argument to `.each()` function, and passing params to `.definition()` function for the seeder. Additionally, the user modified the entity generator to include the `orderBy` option, and fixed an issue related to data loader, ensuring the `orderBy` option is respected when dataloader is enabled.
sqlite-databasesmysql-mongodbentityunit-of-workunit
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