Kamil Jakubczak, Software Developer in Poznań, Poland
Kamil Jakubczak

Software Developer in Poznań, Poland

Member since June 17, 2017
Kamil is a React, React Native, and JavaScript enthusiast (with a small dose of .NET experience). He recently became hooked by mobile development, deployment, and whatever is needed for it, mostly due to React Native being superb and fun to work with.
Kamil is now available for hire



  • React, 5 years
  • JavaScript, 5 years
  • React Native, 4 years
  • C#, 4 years
  • Node.js, 4 years


Poznań, Poland



Preferred Environment

MacOS, Git, WebStorm, VS Code

The most amazing...

...thing I've developed is a mobile app from zero to deployment within three weeks with payments and native calendar integration.


  • React Native Developer

    2018 - 2018
    Ceracare (via Toptal)
    • Created the whole application from scratch.
    • Used sketches to make an application.
    • Created logic within the application.
    • Proposed models provided by the API by defining how we should handle it.
    • Contributed to the app for both iOS and Android devices.
    • Helped make crucial design decisions.
    Technologies: React Native, Push Notifications, Expo
  • React & React Native Developer

    2017 - 2018
    Brand Method (via Toptal)
    • Created a register screen.
    • Improved code quality.
    • Introduced necessary back-end functions within Firebase cloud functions.
    • Added background tasks to the application.
    • Added a scheduling system by introducing cron jobs with Firebase cloud functions.
    Technologies: React, React Native, Firebase, Firebase Cloud Functions, Stripe
  • React Native Developer

    2017 - 2018
    Suits & Sandals (via Toptal)
    • Resolved some final problems with a React Native application.
    • Added Firebase tracking and performance tools.
    • Improved code quality.
    • Prepared necessary prerelease items for release.
    • Fixed performance issues.
    Technologies: React Native
  • Full-stack Developer

    2016 - 2018
    • Introduced ES6+ to the team, which previously used only ES5 in applications.
    • Taught team members about new technologies in the front-end and replaced old Angular 1.1 as a result if there was such a chance.
    • Created the first Node.js application in the company and introduced a way of hosting it.
    • Created the first .NET Core application that easily was integrated within the company.
    • Improved the possibility of using .NET Core within the company by introducing build changes and doing proofs of concept.
    • Analyzed client requirements and also represented the company.
    • Created the first mobile application within the whole company, using React Native.
    • Created all necessary building steps for mobile development, introducing such technologies like Bitrise, Fastlane, Crashlytics, and Fabric.io.
    • Maintained multiple production applications.
    • Often assigned to tasks related to improving front-end performance.
    • Introduced new technologies like CSS Modules to handle problems in a more pleasant way.
    • Taught and helped colleagues from all teams with more complicated problems.
    Technologies: React, React Native, .NET, .NET Web API, .NET Core, .NET MVC, Dapper, Knockout
  • Freelance React Native Developer

    2017 - 2017
    GistApp (via Toptal)
    • Built a React Native application.
    • Rewrote code to Redux architecture.
    • Cleaned up code and set up good code practices.
    • Prepared complex animations.
    Technologies: React Native
  • Full-stack Developer

    2015 - 2016
    Sputnik Software
    • Created a new government application where you could apply for funding. It was also the very first application in the company that abandoned Knockout and picked React.
    • Suggested React as a main library that all company solutions will be based on.
    • Started planning microservice-based architecture with Docker and Node.js.
    • Created the company identity system as a microservice for other services using Node.js and OrientDB.
    • Created a CMS with a Node.js-based back-end and React-based front-end that was presented to clients as a revolution of the current solution.
    • Led one of the R&D teams.
    • Planned a solution for two big government institutions for sharing customers and keeping them in sync.
    • Gave technical interviews for JavaScript developer candidates.
    • Educated colleagues on the proper testing of Node servers and front-end applications.
    • Maintained multiple production applications.
    • Analyzed client requirements.
    • Reviewed the code of every developer within the R&D team.
    • Introduced Git flow as a way to handle changes within our applications and to have more control over them.
    Technologies: Node, .NET, React, SCSS, MongoDB, JavaScript, Git, MS SQL, .NET Web API, .NET MVC
  • .NET Developer

    2013 - 2015
    Sputnik Software
    • Supported a big platform that included a few applications used by citizens to apply for government funding for cultural projects (movies, literature etc.), cultural heritage (renovation), and cultural events.
    • Analyzed requirements for clients and planned steps to take for introducing new features.
    • Managed legacy code while simultaneously creating new features.
    • Presented the product to the client.
    • Advised the client on changes and technology choices.
    Technologies: .NET, WebForms, ASP MVC, Knockout, MS SQL, EntityFramework, Git


  • OIDC Client for React Native (Other amazing things)

    An ODIC client that worked correctly within a Hybrid workflow and according to specifications.

  • Komplett Mobil (Development)

    An application written with React Native made for one of biggest eCommerce clients and their mobile network for iOS and Android

  • FPG (Development)

    Front Pointe Global application for iOS and Android; an application whose whole point is to cast votes and show them in a pleasant format. Native Base is used as a UI tool within the application.

  • Facebook for Products (Development)

    A mobile application where products that you bought could be displayed. You could also share your products with others, get a review on these, and see who buys what. There was also a kind of gamification where you could see other people stuff and tell who is the "trendsetter."

  • Breath Analyzer (Development)

    A mobile app that worked with Breath Analyzer that checked alcohol in breathing air. It had push notifications, background tasks running every some time, checking your current activity (driving a car or not), SMS notifications, asking you to take pictures if there was driving activity (to establish that you were a passenger), random tests as required, or scheduled tests.

  • Toptal Academy Lecturer (Other amazing things)

    I had this amazing opportunity to be a Toptal Academy Lecturer where I tried my very best to explain how React Native works and what new developers should be aware of. I explained whole building process, all necessary elements to create an application and put it on two major stores (Google Play and App Store). Showed how Firebase works, how to style, how to improve performance and use the most out of a Native thread. I explained how it is different from other similar solutions and showed how to create the project and architecture. I explained the difference between RN only and RN with Expo. And finally, I added some good ideas and little-known secrets about React Native.

  • CeraCare App (Development)

    An application for care workers so it is easier for them to know about patients, to get information about their patients, and also to keep everything in check and control. It is also easier to see how patients are feeling on a daily basis.

  • React Tutorial: Components, Hooks, and Performance (Publication)
    In recent years, React has established itself as the most popular library in the JavaScript universe. However, rather than rest on its laurels, the React team is still working hard to make it better. In the second part of our React tutorial series, Toptal JavaScript Developer Kamil Jakubczak takes a closer look at some of its features, including hooks, the latest addition to React.
  • React Tutorial: How to Get Started and How it Compares (Publication)
    In recent years, React went from being an also-ran in the JavaScript universe to the most popular JS library. However, how does React stack up against Angular and VueJS in 2019? In the first part of our React tutorial series, Toptal JavaScript Developer Kamil Jakubczak outlines the reasons behind React’s popularity and explains how to get started on your first React app.


  • Languages

    ECMAScript (ES6), HTML5, ES7, JavaScript, HTML, SCSS, CSS, ASP.NET Razor, CSS3, C#, SQL
  • Frameworks

    React Native, Redux, Swagger, Knockout.js
  • Libraries/APIs

    React, React Redux, React Router, REST APIs, Redux Form, Redux-saga, Node.js
  • Tools

    WebStorm, Git
  • Platforms

    Visual Studio Code, Firebase, MacOS, Azure
  • Paradigms

    DRY, Functional Programming, Agile Software Development, Asynchronous Programming, Object-oriented Programming (OOP), Unit Testing, Test-driven Development (TDD)
  • Storage

    MongoDB, Microsoft SQL Server
  • Other

    EF6 Code First, Google Material Design


  • Master of Science degree in Computer Science
    2014 - 2016
    Poznan University of Technology - Poznań, Poland
  • Bachelor of Science degree in Computer Science
    2010 - 2014
    Poznan University of Technology - Poznań, Poland

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