Dario is available for hire
Hire DarioDario Milicic
Verified Expert in Engineering
Android Developer
Zagreb, Croatia
Toptal member since April 7, 2016
Bio
Dario started programming almost 15 years ago. While at college, he built two startups—web and mobile—and has been employed as an Android contractor for the past 10+ years. He's worked with the YC-funded company Bellabeat and was a contractor for Ericsson, Johnson&Johnson, and Schedulicity. Dario is currently an Android and Flutter consultant and contractor.
Portfolio
Reddit, Inc.
Android, Large-scale Projects, Online Payments, B2C, Consumer-facing Products...
Contentsquare
Android, WebView, Kotlin, Flutter, Software Architecture
DECODE HQ
Flutter, Dart, Riverpod, Mobile Apps, Software Architecture
Experience
- Android - 10 years
- Java - 10 years
- Kotlin - 6 years
- CSS - 5 years
- Ruby on Rails (RoR) - 4 years
- Ruby - 4 years
- Dart - 3 years
- Flutter - 3 years
Work Experience
Android Developer for Large Social Network
2025 - 2026
Reddit, Inc.
- Implemented the Keyword Following feature used by millions of users.
- Implemented the Onboarding-in-feed feature to surface the onboarding flow on the feed.
- Reworked the sharing functionality in the Reddit app, which is not being used by millions of people.
Technologies: Android, Large-scale Projects, Online Payments, B2C, Consumer-facing Products, Kotlin, Jetpack Compose, AI Tools, Software Architecture
Senior Android Engineer
2024 - 2025
Contentsquare
- Developed the Contentsquare Android SDK.
- Made significant improvements to the Android SDK WebView tracking.
- Resolved high-impact client issues with >500,000 ARR.
- Made significant contributions to the API error analysis module.
- Laid the groundwork for the new survey feature of the mobile SDK.
Technologies: Android, WebView, Kotlin, Flutter, Software Architecture
Senior Flutter Developer
2024 - 2024
DECODE HQ
- Worked with an agency called DECODE as a contractor to help them with several high-impact Flutter projects.
- Built multiple complex screens on a tight deadline for large international companies.
- Converted custom designs from Figma with custom styling, animations, and state management, including those with BLoC and Riverpod.
Technologies: Flutter, Dart, Riverpod, Mobile Apps, Software Architecture
Senior Flutter Developer
2024 - 2024
Hellolighten Ltd
- Built the AI-chat cross-platform app as a single developer.
- Implemented complex Figma designs into a functional UI.
- Incorporated features using Dart, GetIt, BLoC, and Dio.
Technologies: Flutter, Dart, Software Architecture
Senior Android/Kotlin Developer
2023 - 2024
Zippe App Ltd
- Built an entire Uber-like app as a single developer.
- Implemented complex Figma designs into a functional UI.
- Implemented features using Kotlin, Compose, Coroutines, ViewModels, Jetpack, Hilt, and REST.
Technologies: Maps, SDKs, Android, Kotlin, Google Maps SDK, Google Maps API, Google Maps, Agile, Jetpack Compose, Figma, App UI, Coroutines, Model View ViewModel (MVVM), Hilt, REST APIs, REST, Software Architecture
Senior Android Developer
2023 - 2023
Cached
- Brought the app from an unusable state to production-ready.
- Implemented and refactored all core features of the app and removed legacy code.
- Implemented several complex screens, including the Onboarding and About You form screens. Fixed UI issues on other screens.
Technologies: Android, Android Jetpack, Android Studio, Firebase, Android SDK, Mobile Apps, Android App Design, Mobile Development, Mobile App Development, Firebase Analytics, Cloud Firestore, Software Architecture
Android Developer
2023 - 2023
Ligence
- Implemented a BLE connection between an Android device and a medical ultrasound to display live images of the patient's heart.
- Developed a neural network model to run an analysis on the provided heart image from the ultrasound.
- Architected and built the app using state-of-the-art components such as Jetpack Compose, Hilt, Flow, coroutines, ViewModel, Retrofit, etc.
- Implemented a server-client protocol for running a server-based neural network.
Technologies: Kotlin, Android, Bluetooth Low Energy (LE), Bluetooth, Neural Networks, Android SDK, Mobile Apps, Android App Design, Mobile Development, Mobile App Development, Software Architecture
Android/Kotlin Developer
2022 - 2023
Swift Medical Inc.
- Implemented integrations with other healthcare apps through deep linking.
- Significantly improved the legacy source code to be more robust, maintainable, and testable.
- Fixed hundreds of bugs and crashes using Jira to track the progress.
Technologies: Kotlin, Android, Bluetooth, Video Capture, Android SDK, RxJava 2, Mobile Apps, Android App Design, Firebase, Integration, Mobile Development, Agile, Mobile App Development, Firebase Analytics, Cloud Firestore, Software Architecture
Senior Android Developer
2019 - 2022
Schedulicity
- Spearheaded the development of the company app for business clients. This includes the software architecture and foundational code for the team.
- Implemented complex features like the calendar, the checkout flow, custom animations, and designs, caching data with the database as the single source of truth.
- Implemented the calendar UI from scratch with features comparable to Google Calendar. This includes swiping, dragging and dropping appointments, zooming, and scaling.
- Implemented over 400 integration and unit tests, covering complex features and UI elements, making regression testing easier.
- Managed a small team of four devs, which included mentoring, 1-on-1s, and code reviews to ensure up-to-standard codes.
Technologies: Android, Kotlin, REST, Android Jetpack, Coroutines, Git, Jira, Android Development, REST APIs, Android SDK, RxJava 2, Mobile Apps, Android App Design, Mobile Development, Agile, Mobile App Development, Firebase Analytics, Cloud Firestore, Software Architecture
Senior Android Developer
2017 - 2019
Johnson & Johnson
- Developed a dynamic UI and other components for reuse in multiple apps.
- Implemented dozens of custom views and animations.
- Consumed a complex REST API with dynamic form data for the UI to display.
- Installed MVP/clean architecture using test-driven development, including technologies like Java, RxJava, and Kotlin.
Technologies: REST, RxJava, Android, Kotlin, Java, Android Development, REST APIs, Clean Architecture, Android SDK, RxJava 2, Mobile Apps, Android App Design, Mobile Development, Agile, Mobile App Development, Software Architecture
Software Contractor
2017 - 2017
Turisticka Naklada d.o.o
- Developed and customized the eCommerce back end using the Spree gem.
- Implemented the provided designs in ERB, a rails framework for the UI.
- Implemented features using TDD with the RSpec gem.
Technologies: Ruby on Rails (RoR), Ruby, REST APIs
Software Contractor
2017 - 2017
DECODE d.o.o
- Implemented a BLE interface between an Android app and a light node device.
- Developed advanced custom UI controls to manipulate the light node device. This included dragging and animating the screen's visual light node to manipulate LED light brightness/color.
Technologies: Bluetooth, Android, Android SDK, Mobile Apps, Android App Design, Agile, Mobile App Development
Android and Rails Contractor
2015 - 2017
Online Freelance Agency
- Built a Tinder clone (easy swipe capability) for jobs in Rails.
- Implemented an MVP car racer Android app which tracks racer GPS locations and displays them on a map.
- Developed a fintech app (LendingCircles) integrated with Salesforce.
- Refactored and bug-fixed several poorly maintained projects which dramatically increased stability.
Technologies: Ruby on Rails (RoR), Ruby, Android, Android Development, REST APIs, Clean Architecture, Android SDK, Mobile Apps, Android App Design, Mobile Development, Mobile App Development
Android Consultant
2015 - 2015
Ericsson Nikola Tesla, d.d.
- Implemented scanning and connecting to a Bluetooth device.
- Pulled data from a Bluetooth device and displayed it to the user.
- Developed a sync-to-server functionality for Bluetooth data.
Technologies: Java, Android, Android Development, Android SDK, Mobile Apps, Android App Design, Mobile Development, Agile, Mobile App Development
Android Contractor
2015 - 2015
Bellabeat, Inc.
- Developed a sync-to-server functionality for the LEAF app.
- Implemented the main business logic for processing LEAF device data and showing it on the UI.
- Installed token-based authentication, so clients retain logged status.
Technologies: Java, Android, Android Development, REST APIs, Android SDK, Mobile Apps, Android App Design, Mobile Development, Agile
Web Developer
2014 - 2014
Paul Scherrer Institute
- Implemented the CKEditor onto their electronic workbook software.
- Developed the responsive design for their electronic workbook software.
- Designed a responsive layout using the Bootstrap CSS framework.
Technologies: JavaScript, CSS, HTML
CTO | Co-founder
2013 - 2014
Potrosko
- Developed an Android app for tracking phone costs.
- Built the back-end server in Django for supporting the mobile app.
Technologies: Django, Android
Android Contractor
2013 - 2013
Times Computers d.o.o
- Worked on an internal Android survey app.
Technologies: GPS, Java, Android, Android Development, Mobile Apps, Mobile Development, Google Maps SDK, Google Maps
Front-end Developer
2010 - 2010
XHTMLmagic.com
- Converted several PSD formats to HTML.
Technologies: JavaScript, CSS, HTML
Project History
Flutter Tic-Tac-Toe
An open source tic-tac-toe game with AI built in the Flutter framework. The UI was done in Flutter using standard Google practices. The AI was created using the min-max algorithm with the alpha-beta pruning modification. The AI can never lose the game.
Android Clean Boilerplate
https://github.com/dmilicic/Android-Clean-BoilerplateThis is a boilerplate project I wrote for kickstarting Android apps using the Clean Architecture approach.
Bellabeat LEAF App
https://play.google.com/store/apps/details?id=com.bellabeat.cacao&hl=enAn Android app for connecting with LEAF smart jewelry. It pulls and processes data from the LEAF gadget and shows it to the user on a simple UI. It also syncs the data with the back-end for further processing.
Android Cost Tracker
https://github.com/dmilicic/android-clean-sample-appThis is a sample project that I built as a showcase. This cost tracker app is written using the Android Clean Boilerplate. A user can manage and track his costs, and the app syncs the data with the server.
Rails Cost Tracker
This is the web part of the cost tracker app. This web page displays all the costs entered on the mobile app. These costs are displayed in real time utilizing websockets and implemented in Ruby on Rails.
A Detailed Guide on Developing Android Apps Using the Clean Architecture Pattern
This is a blog post about developing Android apps in a way that makes them independent of frameworks, UI, or databases. Most importantly, it makes them easily testable and maintainable.
It provides a boilerplate project to kick-start Android apps in a clean way and provides a sample application to showcase how all of it works on a real app.
This blog post was featured in Android Weekly #191.
It provides a boilerplate project to kick-start Android apps in a clean way and provides a sample application to showcase how all of it works on a real app.
This blog post was featured in Android Weekly #191.
Ruby on Rails eCommerce App
https://www.turisticka-naklada.hr/Here, I implemented and customized the back-end using the Spree gem. During development, I guided the client on running an eCommerce website and provided marketing and other business advice. I also integrated the Braintree payment gateway as their payment processor.
Personal Website
A Flutter-based personal website that highlights my experience and showcases other hobby projects and publications. The website was created as a scrollable canvas with project cards surrounding my main profile.
Interactive Family Tree for a Social Network App | Flutter
https://dev.kinnectd.com/I was tasked with building an interactive family tree for an MVP for a new social network app in Flutter.
The family tree had to display family data dynamically, family members had to be selectable, and their data had to be loaded and displayed when selected. I built the interactive tree using custom painters in Flutter by drawing everything on a canvas. Data was consumed from a REST API.
A video of the feature can be seen here: https://dmilicic-blog.s3.us-east-2.amazonaws.com/family_tree_ancestor_loading.webm
The family tree had to display family data dynamically, family members had to be selectable, and their data had to be loaded and displayed when selected. I built the interactive tree using custom painters in Flutter by drawing everything on a canvas. Data was consumed from a REST API.
A video of the feature can be seen here: https://dmilicic-blog.s3.us-east-2.amazonaws.com/family_tree_ancestor_loading.webm
Education
2013 - 2016
Master's Degree in Computer Science
University of Zagreb: Faculty of Electrical Engineering and Computing - Zagreb, Croatia
2010 - 2013
Bachelor's Degree in Software Engineering
University of Zagreb: Faculty of Electrical Engineering and Computing - Zagreb, Croatia
Skills
Libraries/APIs
REST APIs, jQuery, RxJava 2, Google Maps SDK, Google Maps, Google Maps API, RxJava, Three.js
Tools
Android Studio, Firebase Analytics, Git, Atom, Sublime Text, Tmux, Android Jetpack, Jira, Figma, WebView
Languages
Java, HTML, Kotlin, Dart, Python, Ruby, CSS, JavaScript, C, C++
Frameworks
Flutter, Android SDK, Ruby on Rails (RoR), Django, LibGDX, Ruby on Rails 4, Riverpod
Paradigms
Clean Architecture, Mobile Development, Agile, REST, Model View ViewModel (MVVM), B2C
Platforms
Android, Firebase, OS X, Bluetooth Low Energy (LE), Web
Storage
Cloud Firestore, PostgreSQL, Redis
Other
Android Development, Mobile Apps, Android App Design, Mobile App Development, AI Tools, Software Architecture, Firebase Hosting, Full-stack, GPS, Bluetooth, Coroutines, Video Capture, Neural Networks, Artificial Intelligence (AI), Integration, Maps, SDKs, Jetpack Compose, App UI, Hilt, WebAssembly (Wasm), Visualization, Graphs, SVG, Large-scale Projects, Online Payments, Consumer-facing Products
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