Jack Tomaszewski

Tech Lead

Led modernization of 20-year-old C# healthcare SaaS serving majority of US medical universities. Migrated to modern Node.js/React stack while maintaining continuous service.

• Designed incremental migration strategy using strangler fig pattern to minimize risk and cost
• Built API gateway to route traffic between legacy and modern services
• Established modern CI/CD pipeline with automated testing and infrastructure as code
• Recruited and led team of 4 engineers, establishing coding standards and review processes

Founder

Built tournament management SaaS platform from scratch.

• Architected cross-platform application (web/iOS/Android) using React Native with Expo
• Leveraged AI tools to accelerate development workflow and code generation

Tech Lead

Led a 10 person team building a part of the biggest e-commerce website in Poland - Allegro Lokalnie (8 mln unique visitors weekly).

• Reduced on-duty alerts to near zero through proactive monitoring improvements
• Reduced infrastructure costs by 40% through optimization
• Migrated front-end from legacy Elixir code to internal low-code framework
• Mentored engineers, conducted recruitment interviews, and performance reviews

Senior Software Engineer

Helped build an Australian property management and fintech platform that helps 100k+ property managers, landlors and renters work better, together.

• Worked on back-end (node.js micro-service architecture with a GraphQL federated gateway), front-end (TypeScript, React, React Native) and DevOps (created CLI tool for deployment of Ailo micro-services to Kubernetes on AWS cloud).
• Helped with system design, took active part in recruitment, established many code standards, and done a lot of mentoring.

Lead Software Engineer

Built web platform for collaboration between doctors and patients.

• Coordinated work of front-end and back-end dev teams. Closely worked with the project manager and the product owners.
• Designed the system architecture. Bootstrapped front-end, back-end and DevOps work. (A HIPAA-compliant stack powered by AWS CDK.)

Senior Software Engineer

Led development of a new front-end for one of the biggest American companies in the hospitality and entertainment industry.

Senior Software Engineer

Worked on SaaS ATS platform helping recruiters manage job offers and candidates.

• Led front-end migration from AngularJS to Angular 2, TypeScript, and Redux
• Migrated Elixir/Phoenix backend from monolith to event-driven umbrella apps
• Developed and released cross-platform mobile app using Ionic Framework

Lead Software Engineer

Built entire SaaS and marketplace platform for booking tourist tours worldwide.

• Created marketplace (Ruby on Rails) for browsing and booking tours with multi-branding support
• Built React/Redux SPA for partners to manage offers, pricing, orders and agents
• Implemented custom embeddable widgets for partners' websites

Lead Software Engineer

Built and maintained a social platform, that lets users easily find the best music fests, organize their trip and personalize their festival experience.

• Created a responsive front-end web app. (in Ruby on Rails and AngularJS)
• Created a cross-platform mobile app. (in Ionic Framework for Android and iOS).
• Developed unit and end-to-end tests for both front-end and back-end.
• Wrote automatic synchronizations with remote APIs, that e.g. parse user's friendships, favourite music artists and festivals from multiple services. (e.g. Facebook, LastFM, Spotify)
• Developed a full-text search using Elasticsearch, with various filters and a custom suggestion system based on the user's own personal music taste.
• Maintained automatic horizontal scaling of the web servers' infrastracture using Chef.

Full-stack Software Engineer

• Created multiple web applications, participating in the whole process of their development: product design and estimation, code design and development, DevOps, UI/UX design, product launch and maintenance. (jtom.me/portfolio)
• Co-organized several tech meetups and conferences (e.g. Meet.js Summit, PolyConf, ng-poznan, AKAI).
• Gave copious tech talks. (On many local meetups, both locally and abroad; and also on a biggest Polish front-end conference, Meet.js Summit, twice.)
• As a part of the team, gained awairds in several hackatons and startup contests. (Poznan Startup Weekend 2012, Startup Poznan 2014, Poznan Startup Sprint)