Michael Mankus, Developer in Szczecin, Poland
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Michael Mankus

Verified Expert  in Engineering

Software Developer

Location
Szczecin, Poland
Toptal Member Since
February 23, 2022

Michał started programming at the age of 14. He has over a decade of practice in a vast number of environments, both technical and cultural. He is experienced with iOS, Flutter, Node.js, back ends, gaming, DevOps, web security, and more. Michal has worked with teams across the globe, in the USA, Eastern and Western Europe, and the Middle East. He has self-started multiple projects and is a hardworking, team player, empathetic, and detail-oriented professional.

Portfolio

Saudi Digital Bank
SwiftUI, Swift, GitLab CI/CD, DevOps, Web Security, Agile, Architecture...
Freelance
Flutter, Node.js, iOS, Swift, Cloud, Amazon Web Services (AWS), UIKit, NestJS...
Reddit, Inc.
Swift, iOS, Xcode, Swift 4, Feature Planning, Objective-C...

Experience

Availability

Full-time

Preferred Environment

Swift, TypeScript, Node.js, Docker, NestJS, UIKit, Express.js, MySQL

The most amazing...

...thing I've developed is the most popular RP GTA game mode in Poland in high school. I made money from it and learned a lot of soft and technical skills.

Work Experience

Principal Software Engineer

2023 - PRESENT
Saudi Digital Bank
  • Conducted around 30 technical interviews and screenings for senior iOS positions. Created a list of technical questions from easy to very hard difficulty.
  • Refactored a whole existing architecture after previously fired consulting firm team. Introduced modularity, reusable packages for multiple targets (SME, retail, and enterprise), and testable code standards.
  • Increased overall test coverage from 15% to 80% by introducing new architecture, minimum test coverage in pull requests, teaching internal iOS engineers how to make testable code, and introducing snapshot tests.
  • Created a reusable design system, common foundation, and more packages, increasing solution reusability across multiple squads and lowering points of failure.
  • Standardized fonts, spacings, colors, layout guides, and the overall look of view components by working together with design team leaders, making the overall feel and user experience even across the whole app.
  • Introduced security standards for SonarQube static analysis and made sure that the application met banking regulator requirements to make the app ready for public release.
Technologies: SwiftUI, Swift, GitLab CI/CD, DevOps, Web Security, Agile, Architecture, Technical Recruiting

Mobile and Back-end Engineer

2016 - PRESENT
Freelance
  • Made a Flutter NFC personal card for Formula 2 racing driver Louis Delétraz. Created a complete mobile and back-end solution and received very uplifting recommendations for excellent, smooth, and bug-free delivery.
  • Developed a Yacht monitoring system for Stocznia Darłowo using Raspberry PI for back-end reading sensors and an iOS front-end app working offline over a local network.
  • Developed a fashion-oriented app in Flutter with push notifications for clothes drop alerts. It reached a high 4.6 rating in the app store after 100 reviews.
Technologies: Flutter, Node.js, iOS, Swift, Cloud, Amazon Web Services (AWS), UIKit, NestJS, Express.js, Python 3, Raspberry Pi, Push Notifications, Apple Push Notifications, OneSignal, Model View ViewModel (MVVM), JavaScript, TypeScript, CocoaPods, Carthage, Realm, Xcode, Swift 4, Swift 5, Swift 3, Swift 2, Swift 1, Native Mobile Apps, Mobile Apps, Mobile App Development, WebSockets, RxSwift, Objective-C, SwiftUI

iOS Engineer

2022 - 2022
Reddit, Inc.
  • Implemented two experiments that led to a 3% higher ad revenue and a 2% increase in good visits in subreddits without any bugs, crashes, and delays.
  • Rewrote the VideoPlayer module to use a flex layout for improved performance.
  • Proposed a feature that received a lot of applause and was planned into the roadmap.
Technologies: Swift, iOS, Xcode, Swift 4, Feature Planning, Objective-C, Model View ViewModel (MVVM), Jira, Figma, Scrum, Firebase, GraphQL, Swift 5, Swift 3, Swift 2, Swift 1, Native Mobile Apps, A/B Testing, Mobile Apps, Mobile App Development

Core Team Senior iOS Software Engineer

2020 - 2022
Middle Eastern Fintech (Digital Bank)
  • Developed a new digital bank from scratch, working since sprint zero in the core team alongside the iOS chapter lead as his right hand with 14 other iOS software engineers in the whole chapter.
  • Designed for all squads multiple core solutions like a form validation system, reusable UI components and styling, widgets, and more.
  • Implemented a highly secure onboarding and login flow for banking purposes.
  • Prototyped basic OneSignal push notifications iOS and Node.js integration for demo purposes as per urgent request of the head of Development. The whole integration took a few hours and is publicly available on GitLab.
  • Contributed and reviewed Spring Boot Java code. Fixed urgent crash in the onboarding while all back-end engineers were unavailable.
Technologies: Swift, UIKit, Model View ViewModel (MVVM), Web Security, CocoaPods, Xcode, Swift 4, Swift 5, Swift 3, Swift 2, Swift 1, Native Mobile Apps, A/B Testing, Mobile Apps, Mobile App Development

Senior iOS Software Engineer and Solution Architect

2020 - 2020
Ingenious.build
  • Created a business proof coordinator pattern for navigation around the app, a robust and reusable form module, generic listing, fancy animated quick actions module, and more.
  • Managed communication between the business team and the engineering team by writing user stories, tracking work in Jira, and doing weekly work progress reports.
  • Fixed multiple memory leak issues and optimized the navigation flow in the existing application, reducing memory usage from over 500 MB to less than 60 MB.
Technologies: Swift, UIKit, Model View ViewModel (MVVM), CocoaPods, Carthage, Xcode, Swift 4, Swift 5, Swift 3, Swift 2, Swift 1, Native Mobile Apps, VIPER Architecture, Mobile Apps, Mobile App Development, RxSwift

iOS Software Engineer

2018 - 2020
Intive
  • Improved a few algorithms from O(n^2) and O(n^3) to O(n).
  • Improved an image processing algorithm from 3s to 0.06s computing time.
  • Managed to constantly be ahead of time with features delivery and without significant bugs.
Technologies: Swift, UIKit, Web Security, CocoaPods, Carthage, Xcode, Swift 4, AVFoundation, Streaming, AirPlay, Swift 5, Swift 3, Swift 2, Swift 1, Native Mobile Apps, Mobile Apps, WebSockets, Video Streaming, RxSwift, Objective-C

DevGaming | Gaming Platform

DevGaming is a commercial role-play game based on Multi Theft Auto (MTA) SDK multiplayer for GTA San Andreas.

It is visited by nearly 2,000 people daily, and over 300 users play simultaneously every evening. Its highest record has been 650.

KEY DELIVERABLES
• Architected and developed game-play in Lua C++ with high efficiency and security in mind. It's had a year-to-year growth of popularity and revenue.
• Profiled the code and improved performance in critical areas.
• Built and supervised a remote team of five developers and 30 game masters and moderators.
• Introduced Scrum and Jira for developers, and currently serving in the role of PO, scrum master, and code reviewer.
• Brought multiple young programmers into professional software engineering careers.
• Monetized the freemium game by developing two currencies, encouraging 80% of players to use paid services and items.
• Maintained a balanced economy encompassing a real estate and vehicles market, organized crime, police, court trials, diverse businesses, furnishing of buildings, and tuning cars.

Amployed.io Niche Job Boards Platform

http://amployed.io
KEY DELIVERABLES
• Developed configurable and scalable software to bootstrap an advanced job board website in a matter of a day.
• Created an innovative matching algorithm for passive job recruitment.

As a result of this platform, a Formula 1 engineer with 20 years of experience managed to find a job in the International Federation of Motorsport (FIA) through our motorsport job board.

Weighter

https://apps.apple.com/pl/app/weighter-gym-notes-progress/id1209089128?l=pl
Weighter is a Swift written application used to record users' fitness progress at the gym. The main goal was to make this app as easy as using a notebook.

In January 2018, Weighter was the top app in fitness and the second-highest app in all paid apps in Poland. It presented steady sales without marketing, long-term users, and a 4.6 rating in the Polish App Store.

KEY DELIVERABLES
• Implemented the graph drawing feature from scratch and managed full offline support using a local database.

Czynna Niedziela

Czynna Niedziela is a mobile app made by two friends and me for searching nearby grocery stores that are open on Sunday in Poland. Project discontinued.

It had 15,000 Android and iOS downloads in the first month since the release and a 4,9 rate with over 100 voters on iOS after three months of development.

I was interviewed about the app on two radio stations, RMF MAXX and Radio Szczecin, and on a national TV station called TVN Business.

KEY DELIVERABLES
• Designed, developed, and released it in just four weeks. It has a smooth interface even with 1,000 places to display.

Short URL for iOS Safari

A plugin to generate short URLs for iOS 15 Safari developed in JavaScript.
It has a 5.0 rating and many day-to-day downloads in the App Store.

KEY DELIVERABLES
• Used Bit.ly REST API for generating short URLs of the currently viewed website. It supports iPhone, iPad, and macOS.

Languages

Swift, Lua, Swift 4, Swift 1, Swift 2, Swift 3, Swift 5, TypeScript, JavaScript, SQL, Objective-C, PHP, Python 3, GraphQL

Frameworks

UIKit, SwiftUI, NestJS, MapKit, Express.js, Flutter, Core Location, Combine

Tools

Xcode, NGINX, Apple Push Notifications, OneSignal, Jira, Figma, Apple HealthKit, GitLab CI/CD

Paradigms

Model View ViewModel (MVVM), Scrum, VIPER Architecture, DevOps, Agile

Platforms

iOS, Safari, Docker, Amazon Web Services (AWS), Raspberry Pi, Firebase, Ethereum, Blockchain

Other

Native Mobile Apps, Mobile Apps, Mobile App Development, IT Project Management, Algorithms, Memory Management, Computer Science, Safari Extensions, Software Project Management, A/B Testing, Monetization, WebSockets, Video Streaming, FiveM, Web Security, Cloud, Push Notifications, Location Services, English, Carthage, AVFoundation, Feature Planning, Streaming, AirPlay, ERC-20, Crypto, Cryptocurrency, Architecture, Technical Recruiting

Libraries/APIs

Node.js, CocoaPods, DirectX, Sockets, iOS Extensions, HealthKit, RxSwift

Storage

MySQL, PostgreSQL, SQLite, MongoDB, Realm, PostGIS

2014 - 2018

Engineer's Degree in Computer Science

West Pomeranian University of Technology - Szczecin, Poland

APRIL 2016 - PRESENT

TOEIC Gold 215329 (C1/C2)

ETS GLobal

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