Michał Miszczyszyn, Developer in Gdańsk, Poland
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Michał Miszczyszyn

Verified Expert  in Engineering

Full-stack JavaScript Developer

Gdańsk, Poland
Toptal Member Since
July 25, 2016

Michal started coding at nine, progressing from Pascal to TypeScript. He has 15+ years of experience, founded Type of Web, Poland's largest web development community, and authored the bestseller "TypeScript na poważnie." He has trained around 1,000 people through cohort-based courses. Michal is skilled in TypeScript, Python, and Rust and specializes in R&D focused on cutting-edge AI tools. He aims to inspire the programming community with his passion for technology and collaboration.


Online Freelance Agency
Redux, React, Node.js, JavaScript, TypeScript
Freelance Work
WordPress, PHP, jQuery, CSS3, HTML5
Tremor Technologies, Inc.
Hapi.js, Node.js, Observables, RxJS, C3.js, TypeScript, Angular




Preferred Environment

Git, Visual Studio Code (VS Code), MacOS

The most amazing...

...thing I've done was a performance audit and refactoring of a web app (drawing graphs of hundreds of data points) and over 3x improvement in rendering time.

Work Experience

Full-stack JavaScript Developer

2017 - PRESENT
Online Freelance Agency
  • Developed sophisticated web applications for unique clients from all around the world.
  • Successfully led a team of five and built a product.
  • Implemented advanced filtering and searching SQL queries for PostgreSQL.
  • Optimized a React-based application.
Technologies: Redux, React, Node.js, JavaScript, TypeScript

Freelance Front-end Web Developer

2009 - PRESENT
Freelance Work
  • Prepared multiple lightweight and responsive layouts with the use of the newest technologies.
  • Created multiple WordPress themes from PSDs.
  • Coded multiple WordPress plugins from scratch.
Technologies: WordPress, PHP, jQuery, CSS3, HTML5

Full-stack JavaScript Developer

2017 - 2017
Tremor Technologies, Inc.
  • Created the front end of the application from scratch.
  • Prepared plans and estimations for the front-end codebase.
  • Implemented functionalities required for the new reinsurance marketplace application in Angular 2.
  • Created a REST API in Node.js for the purpose of demoing the application.
Technologies: Hapi.js, Node.js, Observables, RxJS, C3.js, TypeScript, Angular

JavaScript Developer

2016 - 2017
Move Technologies (via Toptal)
  • Implemented new features in a large AngularJS application.
  • Supported a legacy app in AngularJS.
Technologies: Less, SCSS, CSS, HTML, AngularJS, JavaScript

Full-stack JavaScript Developer

2015 - 2016
Comet Lab
  • Implemented a performance audit for a web application, pinpointed key performance problems, and refactored the application in order to address these problems which resulted in over 3x rendering time improvement.
  • Created a WebRTC-based multi-user video chat application, including sound recording and transcription features.
  • Developed an interactive application for monitoring status of various devices and drawing graphs of hundreds of points per second using AngularJS and WebSockets.
  • Built a REST API in Node.js for a music-related startup.
  • Implemented new features in an existing React application.
Technologies: WebSockets, PostgreSQL, Hapi.js, Node.js, Flux, React, AngularJS, TypeScript, JavaScript, CSS3, HTML5

JavaScript Developer

2013 - 2015
  • Created a web application for Confr using AngularJS, and a REST API.
  • Developed a REST and WebSockets API using Node.js, WebSockets, MongoDB, and PostgreSQL.
  • Took over the development of an iOS application and delivered the finished product within a month.
  • Conducted code reviews of coworkers' work.
  • Communicated directly with business clients, created scenarios in order to fulfill all the requirements.
Technologies: REST APIs, Objective-C, PostgreSQL, WebSockets, MongoDB, Node.js, AngularJS, JavaScript, CSS3, HTML5

JavaScript Developer

2012 - 2013
Oyatel AS
  • Created a web chat plugin for an existing Telco product.
  • Developed a JavaScript application and did research about the newest, bleeding-edge technologies.
  • Built a mobile application in Backbone.js.
  • Completed research and development of a webRTC-based video chat solution.
  • Created an interactive game platform for a JavaScript conference.
Technologies: Strophe, XMPP, RequireJS, Backbone.js, jQuery, JavaScript, CSS3, HTML5


Use Observables with React declaratively!


Type checking for Hapi.js based on Joi schemas!

Functional ORM

A 100% typesafe SQL query builder.

Meet.js Summit 2018

Meet.js Summit 2018 with over 500 people was the largest JavaScript conference organized in Poland. All the money from selling tickets was donated to a charity!

Meet.js Summit 2017

Meet.js Summit 2017 with over 400 people was the largest JavaScript conference organized in Poland.

Type of Web

Type of Web is a blog I've created. It's one of the most popular technical blogs in Polish.

Meet.js Summit 2013

Meet.js Summit 2013 was a completely free JavaScript conference with over 300 attendees—the largest event of this kind ever organized in northern Poland.

Meet.js Gdańsk

Free front-end meetups organized every two months. It consisted of three 10-minute presentations, food, and beer.
2011 - 2014

Bachelor's Degree in Computer Science

Gdańsk University of Technology - Gdańsk, Poland


jQuery, REST APIs, React, Node.js, ReasonReact, C3.js, RxJS, Backbone.js, RequireJS, Strophe, WebGL


GitHub, Sequelize, Git, Facebook Reason


Flux, AngularJS, Hapi.js, Redux, Angular Material, Swagger, Angular


JavaScript, HTML, CSS3, TypeScript, HTML5, SCSS, ECMAScript (ES6), Reason ML, OCaml, PHP, Objective-C, CSS, Less


Behavior-driven Development (BDD), Test-driven Development (TDD), Kanban, Scrum, REST


MacOS, Visual Studio Code (VS Code), WordPress


JSON, PostgreSQL, MongoDB, MySQL


XMPP, WebSockets, Observables, Domain-driven Design (DDD)

Collaboration That Works

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