Kamil Chmurzynski, Developer in Berlin, Germany
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Kamil Chmurzynski

Verified Expert  in Engineering

Mobile App Developer

Location
Berlin, Germany
Toptal Member Since
December 1, 2016

Kamil is a software engineer who has a passion for mobile and game app development. He started programming in high school, which eventually led to studying computer science at Oxford University. Of the apps he's done, he's proudest of a game similar to Clash of Clans and another one like FarmVille. He worked in many roles—from leading teams, unit and UI testing, to making back ends—and he never shies away from taking on any challenge.

Portfolio

Mediflix
iOS, Video Streaming, Swift, JavaScript, TypeScript
Boorio
Multiplayer, Blockchain, Git, JavaScript, Amazon Web Services (AWS), Clean Code...
Paid Workout
iOS, Swift, Swift 5, Android, Kotlin, HealthKit, Google Fit, Fitbit API...

Experience

Availability

Part-time

Preferred Environment

Git, Visual Studio, Unity, Android Studio, Xcode

The most amazing...

...project I've worked on is an open-face Chinese poker solver, which at the time was the only software of its kind and helped a pro player become more successful.

Work Experience

iOS Senior Developer

2023 - 2023
Mediflix
  • Developed a buffering solution for short-form videos.
  • Created a new architecture to replace the old legacy solution.
  • Introduced code generation for back-end APIs to be used for all clients.
Technologies: iOS, Video Streaming, Swift, JavaScript, TypeScript

Lead Senior Software Developer | Mobile and Back-end Architect

2022 - 2022
Boorio
  • Created a Unity 3D poker game with social features, including chat and invites, allowing gambling by buying crypto chips.
  • Developed a back end written in JavaScript to handle poker game players.
  • Built a back-end blockchain solution that managed players' payments and converted them into in-game chips.
  • Created admin portals to manage game configurations, player statistics, and payment information.
Technologies: Multiplayer, Blockchain, Git, JavaScript, Amazon Web Services (AWS), Clean Code, Amazon Cognito, Firebase, Full-stack, Software Engineering, Mobile Apps, Software, Games, REST APIs, Smart Contracts, AWS CLI, AWS SDK, NestJS, MongoDB, Mongoose, MongoDB Atlas, Node.js, TypeScript, Next.js, React, Amazon S3 (AWS S3), Project Management, GitHub, Startups, API Integration, Payment APIs, APIs, JSON, Back-end, Webhooks, WebSockets, Back-end Development, Cross-platform App Development, Mobile Applications, Mobile Architecture, HTML, CSS, Integration, Leadership, DevOps, Native Mobile Apps, Cross-platform, Microservices, Cloud, Web Development, Web3.js

Lead Senior Mobile Developer | Architect

2021 - 2022
Paid Workout
  • Created an iOS and Android app to encourage users to exercise and undertake fitness challenges. They can use the app's tokens or real cash to compete against others or specific score targets to win money and purchase fitness-related products.
  • Implemented a feature that allows users to participate in classes run by coaches and watch workout videos while the app measures their performance.
  • Integrated the app with HealthKit, Google Fit, and Fitbit to ensure the app got the correct data. The mobile apps also used location and distance tracking for one type of challenge.
Technologies: iOS, Swift, Swift 5, Android, Kotlin, HealthKit, Google Fit, Fitbit API, Apple Watch, Location Services and Maps, Xcode, Git, Android Studio, Mobile Apps, Software Engineering, Architecture, Software, Mobile, Wearables, WatchOS, Android SDK, REST APIs, SwiftUI, Clean Code, Firebase, Mixpanel, Multiplayer, Project Management, GitHub, Startups, Geolocation, API Integration, Payment APIs, JSON, Webhooks, iOS SDK, iOS Native Libraries, Cross-platform App Development, Mobile Applications, Location Services, GPS, Mobile Architecture, Integration, AVFoundation, Leadership, Native Mobile Apps, Cross-platform, Microservices, Cloud

Lead Senior Mobile Developer | Architect

2020 - 2020
Helpar
  • Organized code architecture for an Android project to be viable for production.
  • Created UI solutions to ensure long-term productivity.
  • Composed documentation to describe the back-end API.
  • Implemented video and audio call solutions using Agora.
Technologies: iOS, ARKit, Firebase, Kotlin, Android, Amazon API Gateway, Git, Android Studio, Full-stack, Mobile Apps, Minimum Viable Product (MVP), Software Engineering, Architecture, Software, Mobile, Android SDK, REST APIs, Clean Code, Agora, Technical Leadership, Project Management, GitHub, Bitbucket, Startups, Geolocation, API Integration, QR Codes, JSON, WebSockets, Video Streaming, Cross-platform App Development, Mobile Applications, VoIP, Mobile Architecture, Near-field Communication (NFC), Integration, Leadership, DevOps, Native Mobile Apps, Cross-platform, Microservices, Cloud, Agile

Lead Senior iOS Developer | Architect

2019 - 2019
Calibrr
  • Created a proof-of-concept iOS app for social account management.
  • Made an OpenAPI (Swagger) spec file that documented the back-end API.
  • Built an AWS-based back end to handle app requests.
  • Integrated social network SDKs—Facebook, Twitter, and Snapchat—to use with social profiles within the app.
  • Implemented geolocation services in the app that allowed user interactions.
Technologies: Mobile App Development, Amazon Web Services (AWS), Amazon DynamoDB, Amazon Cognito, AWS Lambda, Swift, iOS, Xcode, Amazon API Gateway, Git, Full-stack, Mobile Apps, Minimum Viable Product (MVP), Software Engineering, Architecture, Software, Mobile, REST APIs, Clean Code, Project Management, GitHub, Startups, Geolocation, API Integration, APIs, JSON, Back-end, Webhooks, Back-end Development, iOS SDK, iOS Native Libraries, Cross-platform App Development, Mobile Applications, Location Services, GPS, Mobile Architecture, Integration, Leadership, DevOps, Native Mobile Apps, Cloud

Lead Senior Mobile and Back-end Developer | Architect

2019 - 2019
RolloMotion
  • Created an iOS Swift and Android Kotlin app for requesting and tracking scooter rides.
  • Developed an internal iOS app to help with scooter management.
  • Created a Swagger and OpenAPI spec to be used as an API between the back-end and apps.
  • Built a back end based on AWS Lambda to support the customer-facing and internal apps.
  • Integrated various services, such as Stripe and Twilio.
Technologies: Mobile App Development, Amazon Web Services (AWS), Twilio, Stripe, Amazon DynamoDB, Amazon Cognito, AWS Lambda, Kotlin, Android, Swift, iOS, Xcode, Amazon API Gateway, Git, JavaScript, Android Studio, Microsoft Visual Studio, Test-driven Development (TDD), Agile Software Development, Full-stack, Mobile Apps, Minimum Viable Product (MVP), Software Engineering, Architecture, Software, Mobile, Android SDK, REST APIs, Clean Code, Node.js, TypeScript, Project Management, GitHub, Bitbucket, Startups, Geolocation, API Integration, Payment APIs, QR Codes, APIs, JSON, Back-end, Webhooks, Back-end Development, iOS SDK, iOS Native Libraries, Cross-platform App Development, Mobile Applications, Mobile Architecture, Near-field Communication (NFC), Integration, Leadership, DevOps, Native Mobile Apps, Cross-platform, Microservices, Cloud

Lead Senior iOS Developer | Architect

2019 - 2019
Tellzme
  • Worked on an iOS app that was a chat and content-sharing platform.
  • Evaluated choices and made final decisions on architecture that transformed a prototype into a real-life product.
  • Created a simple back end on AWS and used Lambda to serve the app.
  • Implemented video, image, and audio-sharing capabilities.
  • Orchestrated an Android team to follow the design, patterns, and technical decisions first made on iOS.
Technologies: Mobile App Development, Firebase, JavaScript, AWS Lambda, Swift, iOS, Xcode, Amazon API Gateway, Git, Mobile Apps, Minimum Viable Product (MVP), Software Engineering, Architecture, REST APIs, Software, Mobile, Android SDK, Clean Code, Technical Leadership, Project Management, GitHub, Startups, API Integration, APIs, JSON, iOS SDK, iOS Native Libraries, Mobile Applications, Mobile Architecture, Near-field Communication (NFC), Integration, Leadership, Native Mobile Apps

Lead Senior Mobile Developer | Architect

2017 - 2019
HomeMD Technologies
  • Created an iOS medical app with Swift, including an EMR, video, and chat messaging system.
  • Built an Android app that was one-on-one with the iOS app using Kotlin.
  • Wrote unit tests to make sure the app was bugfree. The app had to be HIPAA-compliant and secure, as it dealt with medical data.
  • Composed UI tests to make sure iOS and Android apps performed as expected. Created an automated system to run these UI tests on real devices and check if the apps perform as expected.
  • Set up Travis CI to run unit tests and deploy and manage the build process of the apps.
  • Configured Mixpanel and tracking funnels to analyze the apps' performance, such as drop-out ratios.
  • Used Twilio for chat, SMS for text, and VoIP for video messaging.
Technologies: Mobile App Development, Firebase, Mixpanel, Xamarin, C#, Travis CI, JavaScript, Unit Testing, Kotlin, Android, iOS, Swift, Xcode, Git, Android Studio, Full-stack, Mobile Apps, Software Engineering, Architecture, Software, Mobile, Android SDK, REST APIs, Clean Code, MongoDB, Node.js, TypeScript, React, Amazon S3 (AWS S3), Technical Leadership, Project Management, GitHub, Startups, API Integration, Payment APIs, HIPAA Compliance, Stripe API, Stripe Checkout, Stripe Subscriptions, APIs, JSON, Back-end, WebSockets, Video Streaming, Back-end Development, iOS SDK, iOS Native Libraries, Cross-platform App Development, Mobile Applications, VoIP, Mobile Architecture, HTML, CSS, Integration, Jetpack Compose, Realm, Alamofire, Leadership, Native Mobile Apps, Cross-platform, Cloud, Agile, Web Development

Unity Developer

2017 - 2017
ARSports
  • Developed essentially a Pokemon GO clone where a user catches football players.
  • Built a real-time 3D map view for a user to walk in.
  • Created an AR scene where the user could catch football players and appear in the same room as them.
  • Developed a Parse back end for the app to generate football players on the map and maintain user state.
  • Helped to create a system where it was possible to easily modify players' appearance.
Technologies: Unity3D, Parse, Augmented Reality (AR), Unity, Git, Full-stack, Mobile Apps, Minimum Viable Product (MVP), Software Engineering, Architecture, Software, Games, Mobile, Clean Code, Multiplayer, GitHub, Startups, Mobile Applications, Mobile Architecture, Game Development, Video Gaming, Integration, Game Design, 3D Games

iOS Swift Developer

2017 - 2017
Monstar Lab Singapore
  • Processed images to find faces—created algorithms that would be able to detect faces and face edges.
  • Analyzed face data to crop accurate faces from images.
  • Came up with the user UI that improves face detection and cropping.
  • Applied toon shaders to make faces look like cartoons.
  • Created a cartoon app that takes a user's face and puts it into the cartoon so that the user becomes the main character of the comic.
Technologies: Mobile App Development, Cartoons, Image Processing, iOS, Swift, Xcode, Git, Mobile Apps, Minimum Viable Product (MVP), Software Engineering, Architecture, Core Animation, Software, Mobile, Algorithms, Clean Code, GitHub, iOS Native Libraries, Mobile Applications, Mobile Architecture, Integration, Native Mobile Apps

Game Developer

2017 - 2017
Escape the Room NYC
  • Created new puzzles for the Escape the Room game, which would be used in a physical escape room setting.
  • Made use of external specialized hardware that is used inside escape rooms that control the game.
  • Built multi-display views that give the impression of being in a submarine.
  • Developed a periscope view that works like a 3D sonograph.
Technologies: Unity3D, JavaScript, Shaders, Unity, Git, Software Engineering, Software, Games, Clean Code, Multiplayer, GitHub, Game Development, Video Gaming, Integration, Game Design, 3D Games

Unity Developer

2017 - 2017
Speechbytes, LLC
  • Took an existing codebase and wrote from scratch a whole game that helps children with speech impairment improve their speech.
  • Made the game entirely configurable to work with Parse asynchronously so as to not block the user experience.
  • Used physics to make small minigames that oscillate around moving objects.
  • Developed an easy asset deployment system to extend the game further without any code.
  • Created loads of assets that were used in different game modes.
Technologies: Unity3D, Mobile App Development, Drawing, Parse, C#, Unity, Git, Full-stack, Mobile Apps, Minimum Viable Product (MVP), Software Engineering, Architecture, REST APIs, Core Animation, Software, Games, Mobile, Clean Code, GitHub, Startups, Mobile Applications, Mobile Architecture, SQL, Game Development, Video Gaming, Integration, Cross-platform, Cloud

Senior Engineer

2013 - 2017
Wooga
  • Worked on Diamond Dash, an arcade mobile game for iOS in Objective-C.
  • Built tools and frameworks to speed up game making using Objective-C for iOS, Java for Android, and C# for Unity.
  • Developed a game similar to Clash of Clans by Supercell; handled it from conception to production using Unity and C# and served as the lead programmer.
  • Interviewed candidates and improved the interview process at the company.
  • Worked on a farming simulator similar to Hay Day using Unity and C# as the senior lead programmer.
Technologies: Unity3D, Mobile App Development, JavaScript, Android, iOS, Java, Objective-C, Unity, C#, Xcode, Xamarin, Git, Microsoft Visual Studio, Test-driven Development (TDD), Agile Software Development, Full-stack, Mobile Apps, Minimum Viable Product (MVP), Software Engineering, Architecture, REST APIs, Core Animation, Software, Games, Mobile, Algorithms, Android SDK, Clean Code, Multiplayer, Technical Leadership, Project Management, GitHub, API Integration, JSON, 3D, Cross-platform App Development, Mobile Applications, Mobile Architecture, Python, SQL, Game Development, Video Gaming, Integration, Leadership, Native Mobile Apps, Cross-platform, Agile, Game Design, 3D Games

Developer

2013 - 2014
OFC Poker Freelance Project
  • Created the concept and researched multiple ways of solving open-face Chinese poker games.
  • Wrote rules that led to the creation of a manual that helps a player play the poker variant live.
  • Developed an approximator program that produces approximations of the best plays for complex scenarios.
  • Created a solver program that solves the game for all late-game situations and gives appropriate play variants.
  • Built extensions to the program to be used with variants of open-face Chinese poker.
Technologies: Unity3D, C#, Git, Minimum Viable Product (MVP), Software Engineering, Architecture, Software, Games, Algorithms, Clean Code, GitHub, Game Development, Video Gaming, Integration

Software Engineering Intern

2011 - 2011
Ocado
  • Developed a chat application for the iPhone and iPad that works similarly to Skype.
  • Made the chat application work with an internal phone system that would track calls in real time.
  • Created test suites for the chat application and push sever.
  • Deployed a push server using Java to notify users of the chat app.
Technologies: Mobile App Development, Java, Objective-C, iOS, Xcode, Git, Microsoft Visual Studio, Agile Software Development, Mobile Apps, Minimum Viable Product (MVP), Software Engineering, Architecture, Software, Mobile, Algorithms, REST APIs, GitHub, API Integration, Mobile Applications, Mobile Architecture, SQL, Integration, Native Mobile Apps

Age of Trade

An unreleased economical simulation similar to Clash of Clans for iOS and Android devices.

Apart from a very novel gameplay idea, the game had a new semi-3D perspective and dynamic water canals and terrain generation. It was not yet fully optimized at the time but was already looking fantastic on mobile devices.

Role: Lead Developer

Home MD | Android App

https://play.google.com/store/apps/details?id=ca.homemd.homemd
Developed this Android app for Home MD.
It is a medical app that includes an EMR and video/chat messaging system.
It used Twilio for the chat, SMS/text, and VOIP/video calls.
I composed a UI testing suite to make sure the project ran as expected.

tellzme GmbH | iOS App

Developed an app for tellzme, a chat and content-sharing platform.
I created a simple back end on AWS and used Lambda to serve the app. I also advised the Android team on best practices and how to proceed on their end.

Calibrr, LLC | iOS App

Developed an iOS app for Calibrr.

I created a proof-of-concept iOS app for social account management, made an OpenAPI (Swagger) spec file that documented the back-end API, and built an AWS-based back end to handle app requests.

I also integrated social network SDKs—Facebook, Twitter, Snapchat—to use with social profiles within the app and implemented geolocation services that allowed user interactions.

Speechbytes, LLC | iOS App

https://speechbytes.com/
Developed an iOS App for Speechbytes.
Took an existing codebase and wrote from scratch a whole game that helps children with speech impairment improve their speaking skills.
I made the game entirely configurable for it to work with Parse asynchronously not to block the user experience.

AI Crypto/Stock Trading Bot Utilizing the Power of News

A currently ongoing project with a group of AI students. The goal is to create a platform for trading based on impactful news utilizing LLMs for sentiment prediction, reinforcement learning to work out the best trading strategy, and RNNs/LSTMs for stock price forecasting.
2023 - 2024

Master's Degree in Artificial Intelligence

Wroclaw University of Science and Technology - Wroclaw, Poland

2009 - 2013

Master's Degree in Computer Science

Oxford University - Oxford, United Kingdom

Libraries/APIs

REST APIs, iOS Native Libraries, Stripe, Parse SDK, Core Animation, Node.js, Stripe API, Alamofire, Web3.js, HealthKit, Fitbit API, React, LSTM

Tools

MonoDevelop, Eclipse IDE, SourceTree, Paint.NET, Xcode, Microsoft Visual Studio, GitHub, Bitbucket, Travis CI, Android Studio, TortoiseSVN, Git, Subversion (SVN), Amazon Cognito, AWS SDK, Agora, Mongoose, MongoDB Atlas, Stripe Checkout, Visual Studio, AWS CLI

Frameworks

Unity3D, Unity, iOS SDK, LibGDX, Android SDK, NestJS, Next.js, ARKit, SwiftUI

Languages

JavaScript, Java, C#, Swift, Kotlin, Objective-C, Google Apps Script, Python, TypeScript, SQL, HTML, CSS, C, Scala, C++, PHP, Swift 5

Paradigms

Concurrent Programming, Agile Software Development, Extreme Programming, Unit Testing, Refactoring, Test-driven Development (TDD), Testing, Clean Code, Clean Architecture, Cross-platform, DevOps, Microservices, Agile, HIPAA Compliance

Platforms

iOS, Android, Mobile, Amazon Web Services (AWS), Xamarin, Parse, AWS Lambda, Mixpanel, Twilio, Firebase, Apple Watch, WatchOS, Blockchain

Industry Expertise

Project Management

Storage

JSON, Amazon DynamoDB, MongoDB, Realm, PostgreSQL, NoSQL, MySQL, Amazon S3 (AWS S3)

Other

Mobile App Development, Architecture, Mobile Apps, Minimum Viable Product (MVP), Software Engineering, Software, Games, Algorithms, Technical Leadership, Startups, API Integration, QR Codes, APIs, WebSockets, Video Streaming, Cross-platform App Development, Mobile Applications, VoIP, Mobile Architecture, Game Development, Video Gaming, Integration, Leadership, Native Mobile Apps, Augmented Reality (AR), Lambda Functions, Amazon Cognito User Pools, Amazon API Gateway, Full-stack, Multiplayer, Geolocation, Payment APIs, Stripe Subscriptions, Back-end, Webhooks, 3D, Back-end Development, Location Services, GPS, Near-field Communication (NFC), AVFoundation, Cloud, Web Development, Game Design, 3D Games, Drawing, Shaders, Image Processing, Cartoons, Google Fit, Location Services and Maps, Wearables, Smart Contracts, Artificial Intelligence (AI), Artificial Neural Networks (ANN), Data Engineering, Machine Learning, Jetpack Compose, Long Short-term Memory (LSTM), LSTM Networks, Recurrent Neural Networks (RNNs), Reinforcement Learning, Deep Reinforcement Learning, Sentiment Analysis

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