Andrei is available for hire

Andrei Bucurei

Verified Expert in Engineering

Software Developer

Bucharest, Romania

Toptal member since April 11, 2020

Expertise

Back-end Developers Code Review Android iOS Java C#SQL .NET Swift Flutter Kotlin JavaScript Dart

Bio

Andrei is an incredibly versatile software developer with over 15 years of experience. Having led small teams on Android, iOS, and Flutter projects, he brings a strategic architectural mindset to every codebase. Andrei is an expert at navigating complex feature development and system migrations, combining deep technical mastery with a reputation for collaboration and outstanding results.

Portfolio

HungerStation LLC - Main

iOS, Swift, SwiftUI, Flutter

Toptal

Code Review, C#, Python, JavaScript, TypeScript, Swift, Kotlin, Java, Testing...

Freelance Clients - Autowass

Flutter, iOS, Android, Jira, Dart, Java, Gradle, Spring Boot, Angular...

Experience

iOS - 10 years
Android - 10 years
Java - 10 years
C# - 10 years
Mobile Development - 10 years
Swift - 7 years
Kotlin - 5 years
Flutter - 5 years

Preferred Environment

Slack, Jira, Git, Xcode, Visual Studio Code (VS Code), Android Studio, MacOS, Windows, Flutter, SQL

The most amazing...

...full-stack BI app I've developed turned out to be a major improvement in the client's workflow. I am especially proud of its robustness.

Work Experience

iOS Engineer

2025 - 2026

HungerStation LLC - Main

Refactored the main store page, which enhanced UX, reduced Time to Interactive (TTI), improved code maintainability and readability and enabled easier development of new features.
Implemented support for seasonal vendor campaigns, resulting in improved key eCommerce growth indicators.
Revamped parts of the subscription flow, resulting in a more modern UX.
Cleaned up code for concluded experiments, reducing code complexity and technical debt.
Tracked and fixed crashes, contributing to the app quality score and ensuring a user crash rate under 0.02%.

Technologies: iOS, Swift, SwiftUI, Flutter

Technical Screener

2021 - 2025

Toptal

Facilitated over 310 technical interviews for software engineers joining Toptal.
Contributed to content creation for the screening process.
Reviewed over 120 online tests for Toptal candidates.

Technologies: Code Review, C#, Python, JavaScript, TypeScript, Swift, Kotlin, Java, Testing, Slack

Full-stack Developer

2020 - 2025

Freelance Clients - Autowass

Developed new features in the back end (Spring Boot), front end (Angular), and mobile app (Flutter) for a product used for auto services and their customers.
Improved the back-end deployment by configuring a Jenkins instance and pipeline.
Implemented subscriptions using platform-specific mechanisms, App Store, Google Play, and Stripe.
Integrated 3rd-party APIs for vehicle details, parts, and repair manuals.

Technologies: Flutter, iOS, Android, Jira, Dart, Java, Gradle, Spring Boot, Angular, JavaScript, WebSockets, REST, APIs, Firebase, Stripe, SendGrid, Twilio, MySQL, Google Cloud Platform (GCP), DevOps, Subscriptions, SQL, User Interface (UI), User Experience (UX), Leadership, Mobile Development, Rx, RxDart, TypeScript, Back-end, HTML, Clean Code, MongoDB, Technical Leadership, Cross-platform, Mobile App Development, Mobile Applications, GitHub, Mobile Apps, Mobile, Full-stack, Localization, CSS, Visual Studio Code (VS Code), API Integration, Google Play Store, TestFlight, App Store, HTML5

Mobile Developer

2024 - 2024

Waverley Studios LLC

Participated in the tech stack selection, system design, backlog creation, and task estimation during the discovery phase of the project.
Developed a Flutter app for iOS and Android as a solo developer, building it from the ground up, ensuring a scalable, maintainable codebase with high-quality code and a low learning curve.
Converted Figma designs into Flutter widgets, implementing over 20 app pages and more than 100 UI components, ensuring precise design accuracy, correct rendering across devices, and seamless user experience integration.
Managed periodic app releases to TestFlight and Google Play for internal testing, maintaining version control and addressing user feedback for quality assurance.

Technologies: Flutter, Dart, .NET, .NET 8, C#, Azure, SQL, Entity Framework, Android, iOS, REST APIs, APIs, SQLite, Notion, Figma, Estimations, Software Architecture, Nylas API, SendBird, Auth0, Auth0 API, User Interface (UI), User Experience (UX), Responsive UI, Adaptive Design, TestFlight, App Store, Google Play Store, Git, UI Animation

Android App Developer

2024 - 2024

SHIPLINK LAB S.R.L.

Redesigned the application completely, based on a new Figma project.
Integrated new API endpoints for parcel identification and tracking.
Refactored existing code to improve its readability and efficiency.
Updated code that was using deprecated Android APIs.

Technologies: Android, Android SDK, Java, Kotlin, Android Studio, Localization, API Integration

Flutter Developer

2023 - 2023

One28 L.L.C-FZ

Developed a Flutter app for iOS and Android used by DJs around the world to manage their profile and events schedule and accept or deny song requests at their parties.
Developed a Flutter app for iOS and Android used by people to discover DJs and events around them, follow their favorite DJs, request songs, and tip the DJs at their party.
Participated in the design and development of the back end to ensure efficient communication with the apps and minimize costs and development time.
Created and managed the tasks backlog in Jira based on the Figma design and specifications from the client.

Technologies: Flutter, Mobile Apps, Front-end, iOS, Android, Xcode, Dart, Firebase, Cloud Firestore, Firebase Authentication, OAuth 2, Stripe API, Google Pay, Apple Pay, Google Cloud Storage, Google Maps, Software Architecture, User Experience (UX), User Interface (UI), Push Notifications, Architecture, Mobile, Reactive Programming, Full-stack, Localization, Slack, Visual Studio Code (VS Code), API Integration, Google Play Store, TestFlight, App Store

Mobile Developer

2023 - 2023

Straight Up Studios, LLC

Participated in the discovery phase of the project, estimated tasks, and analyzed and compared the potential frameworks and SDKs to use for the development.
Created small proof-of-concept apps to demonstrate the feasibility of the core features using native mobile development SDKs and Flutter.
Built a Flutter application from scratch, following best practices and using a solid architecture that allows it to scale beyond the scope of the MVP.
Delivered the MVP Flutter application usable on iOS, Android, and web.

Technologies: Android, iOS, Mobile Development, Architecture, Software Architecture, Video Streaming, Streaming, Startups, Videos, Requirements Analysis, Estimations, Agile Software Development, Flutter, Dart, REST APIs, Front-end, JavaScript, User Experience (UX), Mobile Apps, User Interface (UI), Live Chat, Mobile, Reactive Programming, Minimum Viable Product (MVP), Localization, Slack, Visual Studio Code (VS Code), API Integration, Google Play Store, TestFlight

Full-stack Developer

2022 - 2022

Freelance Clients - ProPacient

Configured a Debian VM using Amazon Lightsail, .NET runtime, Maria DB, and NGINX with HTTPS using Let's Encrypt.
Developed a RESTful API using .NET 6, following clean architecture principles.
Developed bash scripts for back-end deployment via SCP with almost no downtime.
Led the development of a Flutter mobile application with two flavors.
Released the iOS and Android apps on their respective stores.

Technologies: Flutter, Dart, Flavors, .NET, C#, Clean Architecture, Debian Linux, APIs, Firebase, Push Notifications, Amazon Web Services (AWS), NGINX, Svelte, JavaScript, Scheduling, Leadership, SSH, Let's Encrypt, Swagger, SendGrid, Mobile Development, Rx, RxDart, Back-end, .NET Core, REST APIs, HTML, C#.NET, Linux, Clean Code, Technical Leadership, Cross-platform, Mobile App Development, Mobile Applications, GitHub, Mobile Apps, Architecture, Mobile, Reactive Programming, Minimum Viable Product (MVP), Full-stack, CSS, Visual Studio Code (VS Code), API Integration, Google Play Store, TestFlight, App Store, HTML5

Mobile Lead Developer

2018 - 2022

Groupe OPEN

Established the initial architecture and tech stack for the back end of the iOS and Android apps.
Assisted teams in getting past roadblocks with technical solutions.
Ensured the codebase stayed healthy concerning all aspects (maintainability, performance, and security).
Developed complex features for both Android and iOS.

Technologies: JSON Web Tokens (JWT), Entity Framework, C#, .NET Core, Realm, Swift, Dagger 2, Kotlin, Java, Android SDK, SwiftUI, Mobile, APIs, REST, JSON, Dependency Injection, Unit Testing, Architecture, DevOps, User Interface (UI), User Experience (UX), Leadership, Mobile Development, Rx, RxSwift, RxKotlin, RxJava, Back-end, Model View ViewModel (MVVM), Agile Software Development, HTML, C#.NET, Clean Code, Technical Leadership, Mobile App Development, Mobile Applications, GitHub, Figma, Mobile Apps, Push Notifications, Reactive Programming, Localization, API Integration, Google Play Store, TestFlight, App Store, iOS

Android and iOS Developer

2016 - 2018

Beler Soft

Developed new features for a mobile app used for fertility treatments.
Published Android and iOS applications on their respective app stores.
Migrated the iOS application from Swift 3 to Swift 4.

Technologies: Mantis, Git, JSON, Firebase, Core Data, SQLite, Swift 4, Java, iOS, Android, Front-end, Mobile Development, Rx, RxSwift, RxKotlin, RxJava, Model View ViewModel (MVVM), Agile Software Development, HTML, Clean Code, Mobile App Development, Mobile Applications, Mobile Apps, Push Notifications, Mobile, Localization, API Integration, Google Play Store, TestFlight, App Store

Android Developer

2015 - 2016

Beler Soft

Implemented new features and improved the UI of a hybrid mobile app skeleton, which was developed with Cordova and JQuery.
Added a feature to a mobile app that allowed users to verify the authenticity of wine bottles by scanning a data matrix.
Improved the check-in functionality and notifications of an in-house social application.
Developed an Android app for a work-site logistics company that allowed tracking of the status of waste containers by scanning NFC badges attached to them.

Technologies: XML, Realm, Jenkins, Subversion (SVN), Cordova, Firebase Cloud Messaging (FCM), Near-field Communication (NFC), ZXing, Java, Front-end, Mobile Development, RxKotlin, RxJava, Model View ViewModel (MVVM), HTML, Mobile App Development, Mobile Applications, Mobile Apps, Push Notifications, Mobile, CSS, API Integration, Google Play Store, HTML5

Experience

Inithy

A native iOS and Android application that connects users with their sport and nutrition coaches. The app allows users to create a schedule for their exercises and meals and keeps track of their calorie intake, weight, and muscle growth. Users are organized in communities, similar to gyms. They can create content like recipes, meals, daily or weekly nutrition plans, and exercise plans and share them with other members. The project is designed to be multi-tenant and the mobile apps are built to support customizations of colors, images, content, and active modules, enabling coaches to easily launch their own training app.

Autowass

Acted as a full-stack developer for an automotive service and repair product, accessible to service providers and their customers in web browsers and mobile apps. Working in a small team, I participated in developing all these parts and was focused on building the back end.

ProPacient

Flutter app used by a small community of patients with rare diseases to schedule appointments with their healthcare providers for treatment administration. The app has two flavors, one for patients with Gaucher disease and one for patients with Hunter syndrome.

For this project, I developed the back end and led another developer in building the Flutter app.

Android:
https://play.google.com/store/apps/details?id=com.propacient.gaucher
https://play.google.com/store/apps/details?id=com.propacient.hunter

WiStim

https://www.wistim.com/

Medical mobile application for fertility treatments. The app simplifies medic-patient communication by managing the appointment schedule, the administration of treatments, and the results of medical analysis. The app was developed for Android and iOS. My role in the project was maintaining the Android app by implementing new features, fixing bugs, and publishing updates on Google Play. I migrated the iOS app from Swift 3 to Swift 4 and later to Swift 5 to re-enable publishing.

Education

2008 - 2011

Coursework Toward Bachelor's Degree in Mathematics and Computer Science

University of Bucharest - Bucharest, Romania

2004 - 2008

High School Diploma in Mathematics and Computer Science

Technical College Constantin Istrati - Câmpina, Prahova, Romania

Certifications

MARCH 2020 - PRESENT

Certified Application Security Technical Reviewer

Open Groupe

Skills

Libraries/APIs

RxSwift, RxKotlin, RxJava, REST APIs, Entity Framework, Retrofit, Stripe API, Google Maps, Nylas API, SendBird, ZXing, Stripe, Auth0 API

Tools

Android Studio, Xcode, Jira, Firebase Cloud Messaging (FCM), GitLab CI/CD, Fastlane, SendGrid, GitHub, Firebase Authentication, TestFlight, Notion, Git, Slack, Subversion (SVN), Jenkins, Mantis, Gradle, NGINX, Certbot, Let's Encrypt, Figma, Auth0

Languages

Dart, Kotlin, Swift, Java, C#, SQL, JavaScript, HTML, C#.NET, Swift 4, Java 8, CSS, GraphQL, HTML5, XML, TypeScript, Ruby, Flavors, Bash Script, Pascal, C++, Python

Frameworks

Flutter, Rx, .NET 8, .NET Core, Android SDK, SwiftUI, .NET, OAuth 2, Dagger 2, JSON Web Tokens (JWT), Core Data, Svelte, Angular, Spring Boot, Swagger

Paradigms

Reactive Programming, REST, Mobile Development, Model View ViewModel (MVVM), Clean Code, Agile Software Development, Dependency Injection, Unit Testing, DevOps, Clean Architecture, Requirements Analysis, Cross-platform, Testing

Platforms

Android, iOS, Mobile, Windows, MacOS, Visual Studio Code (VS Code), Firebase, Google Cloud Platform (GCP), Desktop, Linux, Twilio, Amazon Web Services (AWS), Debian Linux, Azure

Storage

JSON, MariaDB, ObjectBox DB, Realm, Databases, Cloud Firestore, Google Cloud Storage, Microsoft SQL Server, SQLite, MySQL, MongoDB

Other

Generics, APIs, RxDart, Back-end, Mobile App Development, Mobile Applications, Programming, Software Architecture, Mobile Apps, Minimum Viable Product (MVP), Code Review, API Integration, Multitenancy, White Labeling, Architecture, OWASP, Push Notifications, Live Chat, WebSockets, User Interface (UI), User Experience (UX), Leadership, Localization, SSH, Front-end, Technical Leadership, Algorithms, Mathematics, Video Streaming, Streaming, Startups, Videos, Estimations, Google Pay, Apple Pay, Web Scraping, Full-stack, Google Play Store, App Store, Responsive UI, Adaptive Design, UI Animation, AI Integration, Artificial Intelligence (AI), Education Technology (Edtech), Near-field Communication (NFC), Cordova, SaaS, Encryption, Subscriptions, Scheduling, HTTPS, Statistics, Cryptography, Geometry, Algebra, Scripting

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