Aleksandar S.

Senior Software Engineer

Aleksandar is a Senior Software and Mobile Engineer with over 14 years of experience, specializing in developing native and cross-platform mobile applications using Android, iOS, and Flutter. He combines deep technical expertise with leadership and mentoring skills to help teams deliver stable, scalable, and user-focused mobile products.

He has collaborated with global brands such as Coca-Cola, Nike, Deloitte, and Johnson & Johnson through both independent projects and consulting engagements. At Circle Medical, he led Android and iOS teams, implemented CI/CD automation, and boosted mobile performance by 300%.

Aleksandar is recognized for creating efficient development processes, maintaining high-quality codebases, and empowering teams to achieve and exceed their goals, consistently delivering impactful and reliable mobile solutions.

Main expertise

  • Flutter
    Flutter 5 years
  • Dart
    Dart 5 years
  • Android
    Android 15 years

Other skills

  • Google Maps
    Google Maps 9 years
  • Mocha.js
    Mocha.js 2 years
  • Zustand
    Zustand 2 years
Aleksandar

Aleksandar S.

Serbia

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Selected experience

Employment

  • Mobile Tech Lead

    Circle Medical Technologies - 3 years 4 months

    Circle Medical is a Y Combinator–backed telemedicine company providing primary care and mental health services via mobile and web platforms.

    • Led Android and iOS teams, driving product delivery and maintaining alignment between engineering, design, and business goals.
    • Implemented technical roadmaps, coding standards, and architecture guidelines, improving code quality and reducing technical debt.
    • Managed the hiring and onboarding of over 15 engineers, growing the mobile team by 300% and introducing scalable agile processes.
    • Designed test automation frameworks and continuous integration pipelines, increasing release frequency while maintaining HIPAA compliance.
    • Partnered with executives and stakeholders to align engineering KPIs with OKRs, balancing product speed and long-term maintainability.

    Technologies:

    • Technologies:
    • Android Android
    • Swift Swift
    • Kotlin Kotlin
    • Firebase Firebase
    • MVVM MVVM
    • Agile Agile
    • REST API REST API
    • Team Leading
    • Android Jetpack Android Jetpack
  • Senior Android Engineer

    Konstrukt - 10 months

    A healthcare software startup focused on building mobile tools to help doctors accurately calculate pediatric medication doses.

    • Developed both Android and iOS native applications, ensuring accuracy, reliability, and medical safety.

    • Designed and implemented a precise dosage calculation system, minimizing input errors.

    • Collaborated with medical consultants and product teams to align design and data validation.

    • Participated in developer hiring and conducted technical interviews.

    Technologies:

    • Technologies:
    • Android Android
    • iOS iOS
    • Swift Swift
    • Kotlin Kotlin
    • REST API REST API
    • SwiftUI SwiftUI
    • Android Jetpack Android Jetpack
    • Android NDK Android NDK
  • Co-Founder & Platform Lead

    Meeliana - 1 year 5 months

    Meeliana is an IoT startup developing a property automation platform for residential and commercial buildings, integrating smart sensors for monitoring and control. The project was part of the Raising Starts Accelerator and showcased at Expo Dubai 2020.

    • Co-founded the company, defining the product vision, roadmap, and long-term strategy.
    • Led the architecture design and development of the IoT platform, integrating cloud-based automation and analytics.
    • Built a scalable API infrastructure and communication layer between IoT devices, mobile apps, and backend services.
    • Defined project milestones, led a cross-functional engineering team, and ensured the timely delivery of new features.
    • Represented Meeliana at industry events, investor meetings, and accelerator programs, securing early-stage funding.

    Technologies:

    • Technologies:
    • AWS AWS
    • Android Android
    • Kotlin Kotlin
    • REST API REST API
    • MQTT
    • Internet of Things (IoT)
    • BLE BLE
  • Senior Mobile Engineer

    MindTrust Labs - 7 years

    MindTrust Labs is a US-based digital consultancy delivering AI-driven, web, and mobile solutions to startups and global enterprises. The company helps clients transform ideas into scalable digital products through innovative design and modern engineering practices.

    • Led the end-to-end development of seven mobile applications across fitness, healthcare, and finance sectors, focusing on performance, usability, and maintainability.
    • Designed and implemented Flutter applications using BLoC for state management, integrating REST APIs, Firebase, and WebRTC for real-time communication and multimedia processing.
    • Developed and maintained CI/CD pipelines using GitHub Actions, enabling automated builds, testing, and deployments, and reducing release time by 35%.
    • Conducted performance profiling and optimization on both Android and iOS, improving app startup times and reducing memory usage.

    Technologies:

    • Technologies:
    • AWS AWS
    • Flutter Flutter
    • Android Android
    • iOS iOS
    • Swift Swift
    • Firebase Firebase
    • Dart Dart
    • REST API REST API
    • WebRTC WebRTC
    • Bloc Bloc
    • SwiftUI SwiftUI
    • GitHub Actions GitHub Actions
  • Community Leadership & Public Speaking

    Niš Tech Community - 1 year 9 months

    • Organized meetups, workshops, and conferences for regional developer communities.

    • Delivered public talks on mobile development, freelancing, and remote collaboration.

    • Helped grow the local engineering network tenfold through mentorship and advocacy.

  • Lead Mobile Engineer (Consultant)

    INGSOFTWARE - 10 months

    A technology company developing connected fitness applications integrating BLE sensors and wearables.

    • Led iOS application architecture redesign using MVVM and RxSwift to improve code maintainability.

    • Improved Bluetooth communication reliability from 70% to nearly 100% through optimized multithreading.

    • Built abstract communication layers for BLE devices, supporting multiple sensor types and vendors.

    • Created a local iOS server with Swifter to mock APIs, enabling offline development.

    • Delivered a proof-of-concept Android version using Kotlin for cross-platform testing.

    Technologies:

    • Technologies:
    • Swift Swift
    • Kotlin Kotlin
    • MVVM MVVM
    • Realm Realm
    • Alamofire Alamofire
    • BLE BLE
  • Lead Android Engineer

    Johnson & Johnson Health and Wellness Solutions - 1 year 3 months

    J&J’s Health and Wellness division develops digital solutions supporting healthy lifestyles, preventive care, and chronic disease management.

    • Led development of multiple HIPAA-compliant mobile applications used by thousands of patients.

    • Designed modular Android architecture to support dynamic content updates and multi-device sync.

    • Integrated apps with Salesforce backends using complex synchronization algorithms.

    • Mentored 5+ developers, conducted weekly code reviews, and optimized CI/CD pipelines for consistency.

    • Ensured code quality, performance, and scalability through strict review and test standards.

    Technologies:

    • Technologies:
    • Java Java
    • Jenkins Jenkins
    • Kotlin Kotlin
    • Retrofit Retrofit
    • MVVM MVVM
    • Jira Jira
    • Dagger
    • Salesforce Salesforce
  • Android Team Lead (Consultant)

    Infinite Leap - 11 months

    Infinite Leap provides location and asset management solutions for healthcare and logistics enterprises.

    • Managed Android team delivery cycles and introduced structured sprint planning and retrospectives.

    • Defined and enforced coding standards, improving overall codebase consistency and quality.

    • Implemented code review and testing workflows, reducing bugs pre-release.

    • Collaborated with PMs and designers to align mobile roadmap with client requirements.

    Technologies:

    • Technologies:
    • Java Java
    • Retrofit Retrofit
    • Jira Jira
    • Git Git
    • Dagger
  • Lead Android Engineer

    Circle Medical - 5 years

    Core member of the mobile team responsible for building Circle Medical’s Android platform from the ground up and scaling it to tens of thousands of active users.

    • Developed HIPAA-compliant Android applications using Java and Kotlin, transitioning the app architecture from MVP to MVVM.

    • Implemented mission-critical features such as video consultations, chat messaging, payment processing, insurance scanning, and PDF viewing.

    • Integrated SDKs like ZoomUS, Stripe, Acuant, and PubNub for communication, payments, and real-time data streaming.

    • Designed modular architecture, enabling parallel feature development across teams and improved scalability.

    • Set up automated test suites using Espresso, JUnit, and Mockito, increasing stability and reducing crash rates by 40%.

    • Collaborated with backend teams to ensure data synchronization and compliance with healthcare standards.

    Technologies:

    • Technologies:
    • Java Java
    • Android Android
    • Kotlin Kotlin
    • Firebase Firebase
    • Retrofit Retrofit
    • Mockito Mockito
    • Espresso Espresso
    • MVVM MVVM
    • JUnit JUnit
    • Agile Agile
    • Dagger
    • Team Leading
    • Gradle Gradle
    • Stripe Stripe
    • Android Jetpack Android Jetpack
    • Bitrise Bitrise
  • Senior Mobile Engineer

    Toptal - 10 years 10 months

    Client Engagements:

    • Led dozen mobile projects for clients ranging from startups to global enterprises, including Nike, Coca-Cola, and Johnson & Johnson

    • Served as Lead Mobile Engineer for a Y Combinator–funded startup, delivering a highly optimized mobile application

    • Achieved 99.5% app stability, reduced crash rates by 40%, and supported a 20% increase in user base within 6 months

    Leadership & Mentoring:

    • Led 3 major delivery projects, including projects within Johnson & Johnson, ensuring 100% on-time delivery through improved processes and clear technical direction

    • Mentored 5+ junior developers through weekly code reviews and pair programming, contributing to 30% reduction in development time as well as improved code quality and increased team productivity and client satisfaction.

    Technologies:

    • Technologies:
    • Java Java
    • Android Android
    • iOS iOS
    • Swift Swift
    • Kotlin Kotlin
    • Retrofit Retrofit
    • Dagger
    • Realm Realm
    • RxSwift RxSwift
  • CEO & Android Team Lead

    Singularity Software - 1 year 3 months

    Founded a software agency specializing in Android development, delivering products for startups and enterprise clients worldwide.

    • Managed a 13-member development team delivering 15+ Android applications.

    • Architected an enterprise-grade app for the oil industry with dynamic UI generation from REST APIs.

    • Rebuilt and modernized “My Diet Coach,” integrating Material Design and CI/CD — scaling the app to over 10M users.

    • Promoted clean architecture, automation testing, and open-source adoption across the team.

    Technologies:

    • Technologies:
    • AWS AWS
    • Java Java
    • Retrofit Retrofit
    • Travis CI Travis CI
    • Bluetooth Bluetooth
    • NFC
  • Senior Android Engineer

    Scopic Software - 7 months

    Scopic Software builds custom software solutions for global clients in healthcare, education, and entertainment.

    • Developed six Android apps integrating Google APIs and third-party REST services.

    • Implemented a Java-based heart rate detection algorithm using fingertip image analysis.

    • Established internal code standards and reusable libraries to improve efficiency.

    Technologies:

    • Technologies:
    • Java Java
    • Android Android
    • Retrofit Retrofit
    • Espresso Espresso
  • Mobile Engineer

    Various Clients - 14 years 9 months

    Aleksandar developed mobile and fullstack solutions for clients in finance, FMCG, eCommerce, and logistics.

    • Built Android and Flutter applications for startups with rapid MVP cycles.
    • Delivered multi-language, offline-capable mobile apps using Room, Retrofit, and WorkManager.
    • Integrated Firebase services for analytics, remote configuration, and crash reporting.
    • Refactored legacy Java apps to Kotlin, reducing code size and improving maintainability.
    • Built multiple Android and web projects for small businesses and non-profits.
    • Integrated APIs such as JustGiving, Twitter, Google Maps, and PayPal using OAuth.
    • Delivered dynamic websites with JavaScript and jQuery for interactive frontends.

    Technologies:

    • Technologies:
    • PHP PHP
    • HTML HTML
    • CSS CSS
    • jQuery jQuery
    • Flutter Flutter
    • Java Java
    • Android Android
    • Swift Swift
    • Kotlin Kotlin
    • Firebase Firebase
    • Retrofit Retrofit
    • MVVM MVVM
    • OAuth2 OAuth2
    • Dagger
    • Realm Realm
    • Material-UI Material-UI
    • REST API REST API
  • Android & Web Developer (Freelance)

    Various Clients - 2 years

    • Built multiple Android and web projects for small businesses and non-profits.

    • Integrated APIs such as JustGiving, Twitter, Google Maps, and PayPal using OAuth.

    • Delivered dynamic websites with JavaScript and jQuery for interactive frontends.

    Technologies:

    • Technologies:
    • PHP PHP
    • JavaScript JavaScript
    • HTML HTML
    • CSS CSS
    • jQuery jQuery
    • Java Java
    • OAuth2 OAuth2
    • REST API REST API
  • Software Developer

    Microsoft Development Center Serbia (MDCS) - 2 years

    Microsoft Development Center Serbia is one of Microsoft’s global R&D hubs, focusing on software innovation and distributed systems.

    • Developed internal tools and test automation systems for Windows and Office teams.

    • Contributed to UI automation frameworks for validation of Windows mobile components.

    • Assisted in backend service design for telemetry data ingestion.

    • Participated in agile sprints, bug triaging, and code quality reviews.

    • Collaborated with cross-functional global teams to align software integration processes.

    Technologies:

    • Technologies:
    • MSSQL MSSQL
    • C# C#
    • .NET .NET
    • DevOps DevOps
    • WPF WPF
    • Agile Agile

Education

  • MSc.Computer Science and Software Engineering

    University of Nis, Serbia · 2011 - 2014

  • BSc.Computer Engineering

    University of Nis, Serbia · 2007 - 2011

Portfolio

  • Sharpen - 1
  • Sharpen - 2
  • Certified Quality Foods - 1
  • Certified Quality Foods - 2
  • Circle Medical - 1
  • Circle Medical - 2
  • Tribe Safe - 1
  • Tribe Safe - 2
  • Tribe Safe - 3
  • Tribe Safe - 4
  • Tribe Health Telemedicine - 1
  • Tribe Health Telemedicine - 2
  • Tribe Health Telemedicine - 3
  • Tribe Health Telemedicine - 4
  • Tribe Health Telemedicine - 5
  • Tribe Health Telemedicine - 6
  • Tribe Health Telemedicine - 7
  • Tribe Health Telemedicine - 8
  • Podium - 1
  • Podium - 2
  • Podium - 3
  • Podium - 4
  • Podium - 5
  • Podium - 6
  • Beyond Pulse - 1
  • Beyond Pulse - 2
  • Johnson & Johnson Health Partner - 1
  • Plickers - 1
  • Plickers - 2
  • Plickers - 3
  • FitzApp - 1
  • My Diet Coach - 1
  • My Diet Coach - 2
  • Fat Finger - 1
  • Fat Finger - 2
  • Nike Techbook - 1
  • Nike Techbook - 2
  • Epicuri - 1
  • NFC Scanner - 1
  • BookingApp - 1
  • BookingApp - 2
  • BookingApp - 3
  • BookingApp - 4
  • HDSereneScapes - 1
  • HDSereneScapes - 2
  • HDSereneScapes - 3
  • Hollywood Walk of Fame - 1
  • Hollywood Walk of Fame - 2
  • Winggit - 1
  • Winggit - 2
  • Winggit - 3
  • Winggit - 4
  • Winggit - 5
  • Everyday Wallpaper - 1
  • Personal Movie Prioritizer - 1
  • Contour Map - 1
  • Heart Rate Monitor - 1
  • ThoughtFI - 1
  • ThoughtFI - 2
  • ThoughtFI - 3
  • Gorilla Weight Lifting - 1
  • Gorilla Weight Lifting - 2
  • Gorilla Weight Lifting - 3
  • Gorilla Weight Lifting - 4
  • Million Beats - 1
  • Million Beats - 2
  • Million Beats - 3
  • Million Beats - 4
  • Million Beats - 5
  • Million Beats - 6
  • Photo Funhouse - 1
  • Royal Children's Hospital - 1
  • Royal Children's Hospital - 2
  • Royal Children's Hospital - 3
  • Royal Children's Hospital - 4
  • Elder Pilot - 1
  • Alphabet - 1
  • iLoveSweet - 1
  • Notifly - 1
  • Letrz - 1
  • Learn to develop - 1

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