Jack Tomaszewski

Full-stack Software Engineer

14 years of experience in front-end and back-end web development.
Ambitious and communicative. Good mentor and tech lead.


  • Back-end: Elixir, Ruby, node.js, SQL databases, in-memory databases (Redis, Memcached), Elasticsearch, RabbitMQ, microservice and event-based architectures. Designed and maintained several web app backends with ~100k LoC.
  • Front-end: JavaScript, TypeScript, React (with Hooks), Angular, Redux, next.js. Led dozens of front-end codebases, i.e. big SPAs with ~50k LoC.
  • DevOps: configured and maintained web servers through AWS CDK, AWS CloudFormation, Ansible, Docker, Chef, SSH. Knowledge of whole AWS stack and experienced in configuring it.
  • Attentive to UI/UX details and high code quality. Fan of unit tests, functional programming, typed interfaces, and DDD.
  • Can help in or take over: project management, estimation and ownership, tech recruitment, client negotiations.
  • Used to participate in algorithm programming competitions.
  • Open to evolving in: Java, Python, Go, Kubernetes, and many else.


Apr 2020 - Jul 2021

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.
Feb 2020 - Apr 2020

Lead Software Engineer

Built a 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 and bootstrapped both front-end and back-end codebases. Managed DevOps (set up a HIPAA-compliant stack with AWS CDK and the CI/CD pipeline). Led most of the engineering decisions throughout the project.
Oct 2018 - Aug 2019

Senior Software Engineer

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

  • Bootstrapped, developed and led most of the decisions throughout the project. Configured the CI/CD pipeline.
  • Helped recruit, onboard and mentor new team members, both in Poland and the US.
  • Convinced the upper management to let the team use best available tools (e.g. TypeScript, React with Hooks, automatic accessibility/visual/unit tests).
  • Actively helped manage, estimate and scope out the project.
Sep 2017 - Jun 2018

Senior Software Engineer

Worked on a SaaS ATS platform that helps recruiters manage their job offers and candidates.

  • Led and coordinated the front-end team to move the front-end stack from AngularJS to Angular 2, TypeScript, Webpack, RxJS and Redux.
  • Helped migrate the back-end (written in Elixir and Phoenix) from a monolith to separate umbrella apps based on an event-driven architecture.
  • Developed and released a cross-platform mobile app. (in Ionic Framework for both Android and iOS)
Jan 2016 - Sep 2017

Lead Software Engineer

Built an entire SaaS and marketplace platform, that allows to book and manage tourist tours and attractions all over the world.

  • Created and launched a marketplace (in Ruby on Rails) allowing end-customers to browse tourist tours, their schedules and prices, and book them online under the Tripsomnia/Partner/Agent's branding.
  • Created and launched a large Single Page Application (in React and Redux) that allows Partners to manage their offers, pricings, orders, customers and agents.
  • Implemented custom JS widgets, that Partners can put on their own website in order to advertise and sell their tours directly.
  • Helped raise an investment from outside VCs.
Jan 2014 - Dec 2015

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.
Aug 2005 - Aug 2017

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)
  • Mentored several developers and teams.
  • 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)


Poznan University of Technology
2012 - 2015 (unfinished)
Computer Science
  • Served as a president of AKAI, a students' research circle focused on organizing workshops and lectures about web development.
  • Co-created the new main public website of Poznan University of Technology.

Other perks

  • Good public speaker. (Long-time member of an english-speaking Toastmasters club.)
  • Knowledge of algorithms and data structures. (Gained awards in Polish Olympiads in Informatics.)
  • Speaks native Polish, fluent English, conversational Spanish and basic Russian.
  • In his free time, likes to blog, dance, travel, and play tennis and volleyball.