Antoni Kępiński

About me

I’m a full stack developer with hands-down experience as an open-source maintainer, passionate about everything in web development, especially performance, accessibility, and privacy. I’m also familiar with the Node.js ecosystem.

I greatly enjoy listening to classical music and traveling when it comes to my side activities.


    TypeScript and JavaScript



Familiar with advanced patterns

    SSR/SSG frameworks

Next.js, Gatsby


Utility and component frameworks, CSS-in-JS


Apollo, DataLoader


SQL and NoSQL, ORMs and query builders

Work history

Full Stack Developer • Omni Calculator sp. z o.o.

Warsaw | November 2021 — Present

We are building a web platform hosting thousands of custom calculators built by scientists, with over 10M unique monthly visitors and multiple mentions in renowned sources like The New York Times, Forbes, and The Washington Post

Founder • Parsify Technologies

Warsaw | March 2022 — Present

The sole proprietorship behind Parsify Desktop, a notepad-based calculator built with extendibility and privacy in mind.

Full Stack Developer • myPolitics

Remote | January 2021 — November 2021

I worked remotely in a Polish startup that aims to educate people of all ages about politics by providing a neutral point of view in interviews with famous politicians and members of youth political parties.

My responsibility was to maintain a web application hosting news and opinion articles, political views tests, etc., based on a modern tech stack; React, Next.js, Styled Components, Apollo, GraphQL, Nest.js, and MongoDB, with a custom design system.

Furthermore, I used for issue management and GitHub to host closed-source and open-source repositories.


Bachelor of Engineering, Computer Science • Military University of Technology

Warsaw | October 2022 — October 2026

High School Diploma • Zespół Szkół Komunikacji

Poznań | September 2019 — April 2022

A Polish high school that features three years of general education, with three extended subjects: computer science, math, and physics.

  • Class president during the final year
  • Solely represented the school in the XLVII Polish Geography Olympiad (2020), managed to get into the second (regional) stage
  • Represented the school with three other colleagues in a combinatorics competition, “KOALA”, organized by the University of Adam Mickiewicz and the Polish Mathematical Society, managed to get into the second (regional) stage


C2 Proficiency — Score 208 • Cambridge Assessment English

June 2021 (no expiration date)


Volunteer • Wielka Orkiestra Świątecznej Pomocy

Janurary 2016 — Present


  • Guest at JS Party podcast (episode 85)
  • Mentioned in Working in Public: The Making and Maintenance of Open Source Software — a book by Nadia Eghbal, published by Stripe Press