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




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
    Golden Era Club, Ltd. (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
    • Took a leading role in introducing new technologies.
    • Lead the team to create new applications from proof of concept to regular apps.
    • Improved the possibility of using .NET Core within the company by introducing improvements to CI/CD.
    • Analyzed client requirements and maintained multiple production applications.
    • Created the first mobile application within the whole company, using React Native that was really well received by its customers.
    • Created pipelines for CI/CD for mobile development from scratch.
    • Helped colleagues with complicated or performance issues in a front-end environment.
    Technologies: React, React Native, .NET, .NET Web API, .NET Core, .NET MVC, Dapper, Knockout
  • 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.
    • Assisted the client with future features and how to solve some more complex issues within a React Native app.
    Technologies: React Native
  • Full-stack Developer

    2015 - 2016
    Sputnik Software
    • Created a new government application where you could apply for funds. It was also the very first application in the company that replaced Knockout with React, where React later became a core library for the company.
    • Started planning microservice-based architecture with Docker and Node.js while maintaining multiple production applications.
    • Created a 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 an evolution of the current solution.
    • Led one of the R&D teams and analyzed client requirements.
    • Planned a solution for two big government institutions for sharing customers and keeping them in sync.
    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.
    • Managed legacy code while simultaneously creating new features.
    • Kept contact with a client and presented changes and possible solutions of requested features from the client.
    • Introduced new technologies to more experienced developers as a way of expanding horizons.
    • Developed 50+ new forms for clients for special events that occurred yearly.
    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

    JavaScript, HTML, SCSS, CSS, ASP.NET Razor, C#, SQL
  • Frameworks

    React Native, Redux
  • Libraries/APIs

    React, Node.js
  • Tools

    WebStorm, Git
  • Platforms

    Firebase, MacOS, Azure
  • Paradigms

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

    MongoDB, Microsoft SQL Server


  • 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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