Aleksandar Nikolić
Mobile Developer

Part of FatCat Coders since:
April 2024
Aleksandar brings over 11 years of experience in mobile technologies, making "mobile development" his second name. With a focus on Swift and iOS, and backed by a versatile tech stack and engineering background, he's the ideal choice if you need smooth, efficient mobile development combined with adaptability.
Calendly
iOS AppApril 2024 - ongoing
Calendly leads the way in automated meeting scheduling, offering team-based scheduling solutions and integrations with advanced security features.
Contributed to the development of the Calendly iOS app, streamlining scheduling by enabling users to set availability, share booking links, and manage meetings efficiently on mobile.
Maintained and developed new features, including Booking Meetings with diverse configuration options, enhancing scheduling flexibility and user experience.
Collaborated within a cross-functional agile team of 10–15 members, delivering high-quality features and continuous improvements.
Main tech stack:
Swift, iOS, SwiftUI, MVVM, UnitTests, GIT
Teladoc
AI-powered solutionJune 2022 - January 2024
Teladoc Health specializes in telemedicine, virtual healthcare, and AI-driven remote medical care via mobile apps and videoconferencing.
Contributed to the development of a health app at Teladoc, fostering seamless patient-doctor interactions and collaborating with a cross-functional team of 30 developers, including 10 external iOS developers.
Utilized Swift 5 and the MVVM pattern to enhance a large-scale codebase, emphasizing Clean Architecture and SOLID principles while ensuring robust code coverage with Unit Tests.
Focused on feature development, bug fixes, and maintenance in an Agile environment, ensuring timely delivery and an optimal user experience.
Main tech stack:
Swift,
Delivery Hero
Payment solutionJune 2021 - June 2022
Delivery Hero is a local delivery platform that operates in over 70 countries, combining technology and human-driven efforts to deliver fast and seamless experiences.
Developed a Payment SDK for credit card integration, designed to be a pluggable and platform-agnostic client solution, with part of the payment logic shifted from the consumer app to the SDK.
Created project architecture, implemented design, covered the project with unit tests, and defined contracts between the client’s app and backend.
Main tech stack:
Swift, UnitTest, MVC, MVVM
CNJ
SolutionJanuary 2019 - June 2021
CNJ delivers digital product design and development, specializing in UX/UI, multi-market websites, apps, APIs, and SaaS solutions.
Developing the Danfoss Installer and DEVI app for Danfoss (Denmark), utilizing a synchronized local database and API server.
The Danfoss Heating application provides plumbers, heating and HVAC professionals, and installers with tools for dimensions, calculations, and documentation, simplifying the sales and installation of Danfoss products.
Main tech stack:
Swift, MVC, MVVM, REST, UnitTests, Localization, SQL
ABP Technologies
iOS ApplicationAugust 2016 - January 2019
ABP Technologies is an international IT services and consultancy company, comprising UI/UX developers and designers, QA engineers, front-end developers, and VoIP experts.
Using native Swift to develop applications from scratch such as: Vaiox, a social networking app with chat and audio/video functionality; CherryFile, a cloud-based file-sharing service; and NoQue, an app for nightclub table reservations.
Responsible for application creation, architecture and design, testing, and app publishing.
Utilizing REST, Push Notifications, In-App Payments, Stripe, Geolocation, SIP, audio/video streaming, and dynamic content.
Main tech stack:
Swift, MVC, REST, Localization
HolyCode
Mobile ApplicationApril 2015 - August 2016
Holycode provides product development, IT nearshoring, ERP development, and low-code development services.
Developed and maintained a mobile solution for managing insurance portfolios in the Swiss and German markets, designing architecture, and implementing new features.
Ensured high-quality application performance by testing on simulators and real devices, optimizing the UI with Auto Layout, animations, and tracking tools.
Integrated REST services, push notifications, and other key functionalities while collaborating closely with Android developers, Product Owners, Designers, and Backend teams.
Followed the SCRUM methodology, contributing to all project phases, from concept creation to app store deployment.
Main tech stack:
Swift, MVC, GIT
Procescom
Mobile ApplicationJanuary 2013 - April 2015
Procescom offers innovative solutions specifically designed for telecom mobile network operators, focusing on mobile core networks and mobile core infrastructure.
Redesigned the application to improve maintainability and developed new features for Telecom Serbia's prepaid promotion system.
Created and maintained large databases.
Implemented detailed logging and handling of external system failures.
Worked with multithreading, TCP/UDP protocols, and provisioning and charging logic.
Contributed to product management, including future planning.
Main tech stack:
Java, Multithreading, TCP/UDP protocols
Bachelor of Software Development, Information Systems
Faculty of Computer Science (RAF), Belgrade
2006-2012
Serbian
English
Wakeboarding
Diving
Skiing
Tennis
Private projects
Besides his extensive experience, Aleksandar has also undertaken several intriguing private projects in related fields. Here are a few of them. (edited)
FormulaV
Application for booking formula simulation competitions.
DBReisekosten App (for Deutsche Bahn):
Rewrote the application from Objective-C to Swift.
Designed new architecture, fixed bugs, and worked on new features.
Utilized REST Services, Push Notifications, and Realm.
Worked in an Agile environment.
Lykke (iOS Developer):
Developed an application for currency and cryptocurrency trading.
Improved application architecture and created new features.
Collaborated closely with Product Owners, Designers, and Backend teams.
Followed SCRUM methodology.
Globaltel iOS App (for the Serbian market):
Used native Swift to develop an application for messaging, audio calling, and streaming videos (TV channels).
Implemented REST Services, Push Notifications, audio/video streaming, dynamic content, sockets, and payments.
QuestaGame iOS App (for the Australian market):
Maintained the application and developed new features using Swift.
Integrated geolocation and chat functionalities.
Scanner App:
Built a new feature for the Scanner app in Swift.
Worked with a local database, image editing/processing, and In-App payments.