Michal Kalis

As part of a 3-member iOS development team, I contributed to the creation of two sports-related applications, RunYourPool (4.9 rating) and SplashSports (4.7 rating). RunYourPool is designed to facilitate the hosting and managing of sports pools, whereas SplashSports serves as a platform for organizing sports contests with cash rewards. My role involved contributing to the design and development of the core applications using the MVVM-C architecture, implementing continuous integration (CI) and continuous delivery (CD) processes with GitHub Actions and Fastlane and maintaining effective communication with designers, other platform developers, and stakeholders.

Additionally, I prepared the applications for unit testing by implementing dependency injection and adhering to SOLID principles, ensuring the high quality and maintainability of our codebase.

A secure communication app with encrypted messenger, email, and storage.

I was responsible for porting a proprietary cryptographic library written in C/C++ for BlackBerry to iOS. Afterward, my job was to build the core app and implement the messenger part utilizing cryptographic primitives and protocols from the library. Our team got the app to a production-ready state with a fully functional chat, email, and storage during the engagement, including features like push notifications, file transfers, audio recording and playback, taking photos, contact verification, and more.

All features—heavily focused on security and privacy—needed to be properly designed considering possible edge cases, security risks, and conformance to proprietary protocols.

With a very tight schedule, our team managed to deliver a complete app with all its features—audio playback, real-time data refresh using Firebase, in-app purchases, and more. For the first couple of weeks, I was the only developer for the iOS app and later on led the iOS development.

A video streaming app of Hallmark's movies and series. Communication is handled via the REST API and data is managed with Core Data. Video is streamed and secured using DRM technology. Once the design is very important, there are various custom layouts and animations with parallax effects, custom collection view layouts, and more.

The app serves Deutsche Telekom customers to access their virtual voicemail and record personal greetings, adjusting fixed-line settings. For the communication with the back end, both IMAP protocol and REST were used, and data was stored using multi-context Core Data. The app is capable of audio file playback and recording. The project was managed under Scrum, where I was one of the two developers working on the iOS app, mostly responsible for the IMAP part.

I was part of a 3-member team developing the app for a US client. It was developed entirely in Swift with a BDD approach. My responsibilities included communication with designers, developing new features, and bug fixing.