maciej simka

i've been working as a front-end dev for more than 5 years now, a lot of this time was spent in software houses on a variety of projects, both greenfield and brownfield, for small startup and for major companies, though recently i've come to value long-term commitment to product company. my interest don't stop on front-end development, i've been exploring elixir and go on my own and would love to do more work in full-stack capacity. besides programming i'm into multiple things like photography, arthouse cinema, third wave coffee, non-fiction books, music and hanging out with my dog.



wroclaw, poland, cet/cest


  • front-end dev at toggl hire /// dec, 2021 - now

  • software engineer, CRO team at brainly /// dec, 2020 - dec, 2021

    i'm responsible for implementing the a/b experiments and together with the whole team am a part of ideation, execution and analysis process in experimentation program.

    • i've implemented a/b tests on high-traffic pages with millions of users.
    • i've been part of the team from the very beginning, coming up with ideas to make our process better.
  • react/react native developer at callstack /// mar, 2019 - nov, 2020

    i've worked on a variety of spas and mobile apps for international clients, both greenfield and brownfield. used technologies included react, react native, node.js, typescript, flow, css modules, styled components, rest apis, graphql, to mention just the major ones.

    • i've worked on a migration of a large ecommerce app from custom ssr solution based on webpack-isomorphic-tools to next.js, greatly improving performance of the whole app.
    • i've been a tech lead in a couple of projects i've worked on.
    • i've prepared and conducted workshops on topics like react and react native performance, rn basics, animations and gestures in rn and ci/cd for rn apps.
  • front-end developer at kiss digital /// may, 2016 - feb, 2019

    i've worked as a front-end developer on projects of varying complexity, from simple landing pages to spas written in angular and then later in react. i've used jquery, less, sass, twig templates, angular 1.x and react.

    • i've written a simple cli tool in node.js to make creating mailings easier for myself. it was allowing to use templates stylesheets and was later inlining all the styles and adding some mailing hacks like uppercase margin for outlook express.
    • i've introduced react in the company by learning it on my own and creating smaller project with it as a proof of concept.
    • i've been a tech lead in a large application built with react and redux for international clothing manufacturer as an internal tool for managing materials sourcing, designing and production.


  • front-end development bootcamp at coder's lab /// jan, 2016 - mar, 2016

  • cultural studies at jagiellonian university /// nov, 2011 - jun, 2014

    haven't graduated, passed 5 semesters


  • html
  • css
  • javascript
  • typescript
  • node.js
  • react
  • redux
  • next.js
  • gatsby
  • react native
  • jest
  • eslint
  • graphql
  • git
  • circleci