Chief Technical Officer
2020 - PRESENTVarius Software- Led a team of 20 software engineers that provided remote outsourcing services as a startup for Authority Builders Co., ECD, Ahold Delhaize, and Samsung.
- Played a major role in performing technical interviews and assembling a team of the most talented software engineers from the University of Belgrade, capable of collaborating in the office and delivering high-quality code for such a big client.
- Developed core system features, prepared code structures, and designed architectural patterns for employees. Introduced each employee to the project and found best-fit positions and teams to maximize their utilization.
- Supervised implementation processes that employees took part in by reviewing their code, reports, and issues for tasks I previously assigned them with Jira and Trello. Managed sprints and made full planning of the development process.
- Oversaw and collaborated on integrating, developing, and securing different third-party software services for payment processing, authentication, and marketing, which directly affected the clients' incomes.
- Managed a team as a technical project manager and lead developer that delivered multiple web development software solutions for Samsung Adriatic, Samsung UK, and Samsung IE by creating them from scratch and enhancing the existing ones.
- Implemented web application features for huge sale campaigns and promotions (e.g., Black Friday) with the team, which successfully helped the clients gain thousands of customers.
- Involved in deploying the client's web platform programming code by using automatically configured Git hooks to multiple environments. Set up automatic deployment using Docker and GitLab software.
- Provided front-end, back-end, and full-stack development, mainly in Flutter (Android and iOS applications), PHP, and Laravel, on core features on most of the projects we outsourced.
Technologies: Bootstrap, CSS, HTML, Ajax, jQuery, JavaScript, MySQL, CodeIgniter, PHP, Docker, Laravel, Java, Node.js, React, GitLab, CentOS, NGINXFlutter Developer
2021 - 2022Kento Health Inc. (via Toptal)- Developed "Kento Health" iOS application intended to help people with heart diseases in US and Canada, using Flutter as a cross-platform development tool.
- Used Get as a state management plugin for the app, which is backend-less, having only Cloud Firestore as a NoSQL database that holds exclusive content of the app. Firebase is also used for authentication purposes.
- Built everything from scratch based on predefined design and features available in Figma prototype. The actual app I've built looks and behaves the same as a prototype, which was the main goal for MVP.
- Integrated Apple Health App data, which can be synchronized through smartwatch or iPhone, and "Kento Health." This application takes and renders data from it in real-time, which is very important for users to track their health state.
- Configured "Apple Store - in-app purchase" for purchasing auto-renewable yearly subscriptions to access the app. Created offer codes for promotions that the partners and testers use.
- Integrated RevenueCat as a back-end system for making and validating purchases. RevenueCat was integrated with their native Flutter plugin since it doesn't have its first-party back-end.
- Rendered historical data, current progress, community scores distribution using different forms of the charts (bars, lines, etc.).
- Deployed the app to App Store, got approval for in-app purchase and its features, so it's available on this URL: https://apps.apple.com/us/app/kento-health/id1583843414.
Technologies: Flutter, Firebase, In-app Purchases, Dart, Cross-platform App Development, iOS, Front-end Development, Cloud FirestoreFull-Stack Developer
2021 - 202110AK Digital LTD (via Toptal)- Developed new features for existing dating websites in five countries (USA, Canada, Australia, UK, and Ireland). Provided fixes for security and functional issues. Created new dating platforms for other EU countries based on existing ones.
- Enhanced all aspects of customer experience for dating websites, which led to a huge growth of income every month. The rise was more than 600% since I took over the project's development, resulting in more than 100,000$ monthly profit.
- Scraped content, images, automatic chat messages from websites that are global leaders in the dating industry.
- Improved scalability of dating platforms to be able to serve millions of users with the highest response rates with "A" ratings on https://gtmetrix.com/. Introduced various database optimizations, Redis caching tweaked NGINX parameters, etc.
- Defined multiple scripts and cron jobs responsible for making daily and weekly backups of all dating platforms, their databases, and file system (more than 1 TB), storing it outside droplet in collaboration with third-party backup providers.
- Integrated RocketGate, PaysafeCard, and CCBill payment providers for buying chat credits, using asynchronous notification systems with webhooks and payout files.
- Provided real-time support by fixing many bugs that escalated as a product of various user behavior, especially using the chat feature and payment system.
- Connected websites with the Everflow marketing platform, used for tracking sign-ups, account verification, and purchase conversions through cookies. Integrated both front-end and back-end cookie validation and complete stats using Everflow API.
Technologies: Laravel, PHP, JavaScript, jQuery, HTML, CSS, Bootstrap, MySQL, Ajax, NGINX, Ubuntu, Payment APIsFull-stack Web Developer
2020 - 2021WBAM Digital (via Toptal)- Developed custom features for existing SuiteCRM system (built in PHP), adapted to the requirements of Payment1 Loan company (https://payment1.com). Was responsible for front and back-end development and DevOps.
- Created and designed MySQL database architecture, capable of supporting a huge amount of records without affecting overall system performance.
- Set up automatic daily synchronization of CRM system to users, payments, and loan records from the data warehouse of the loan company, through an SFTP connection.
- Implemented a lot of raw database queries, supported by various indexes in order to extract full statistics of business processes in an arbitrary timeframe.
- Introduced a tracking cookie to properly identify unique users along with referral data and make it available to the CRM. Tracking consists of referrer websites, visited pages, average time spent, and more.
- Worked on the implementation of a conversion identification system so the system became able to connect users and their data with customers who are signing up in the Payment1 Loan company system.
- Scheduled automatic email campaigns processed by Payment1 custom email server, which were used for customer notifications, promotions, and more.
- Migrated whole CRM system (code and database) from Ubuntu VPS to Windows server, adapted automatic scripts and cron jobs to work in Windows environment, through Virtual machines.
- Maintained web, database, and email server. Was responsible for deployment and monitoring server activities.
Technologies: PHP, SuiteCRM, JavaScript, MySQL, HTML, CSS, Ubuntu, ApacheFlutter Developer
2020 - 2020Eunotics, Inc. (via Toptal)- Developed a Flutter social app called Munch, which uses a gesture-driven user interface that allows groups to decide where they want to eat from.
- Used Firebase as a support for social authentication (Google, Facebook, Apple) and user management.
- Implemented screens' design and functionalities to look and behave exactly as in the pre-defined Invision prototype provided by the designer.
- Introduced a location feature to the app which allows groups to have a unique experience based on the selected location and radius distance on an interactive map with in-built Google Places API search options.
- Implemented a lot of animations on different screens, which makes the gesture-driven interface more powerful and user-friendly, causing the product to look more professional.
- Architected and developed a native deep-linking feature for Android and iOS, which allows new users to easily join the eating decision process. Also, there is a smart push notification system that keeps the app's synchronization in real-time.
- Deployed the app's beta version on Android and iOS to Google Play Store and App Store.
Technologies: Front-end, Cross-platform App Development, iOS, Android, Xcode, Firebase, Dart, FlutterFull-stack Developer (Flutter and Laravel)
2020 - 2020Praktice LLC (via Toptal)- Developed an app for online personal training, where subscribed clients can see video workouts and exercises of their favorite trainers. Responsible for Flutter application, Laravel API, and Laravel MVC Admin Panel.
- Refactored the whole code structure on both sides (Flutter and Laravel API), to be reusable and adjusted with all recommended design patterns (Flutter BLOC, REST API).
- Fixed all design issues in Flutter, created new screens and functionalities based on design provided in Adobe XD file. Design of all pages adjusted to different screen sizes and device pixel ratios.
- Reimplemented API logic in Laravel including the social login, subscriptions, search, feed, favorites, and profile.
- Added new functionalities to existing admin panel including image and video upload, standard forms using Laravel MVC pattern. The front end was implemented using HTML, CSS, Bootstrap, JavaScript, and jQuery.
- Localized all parts of the system (Arabic and English). Flutter app localized with language JSON sheets, Laravel API returned localized database columns based on HTTP Accept-Language header.
- Deployed Android and iOS Applications to Google Play Store and App Store (Test Flight).
Technologies: Ajax, Xcode, Android, Dart, REST API Architecture, Back-end, Full-stack, Trello, CSS, HTML, jQuery, Bootstrap, JavaScript, MySQL, PHP, Laravel, FlutterFull-stack Developer
2019 - 2020Kintek Group (via Toptal)- Developed the "COVID Access" mobile app using the Flutter framework and Spring Boot and PostgreSQL. It provides COVID-19 Stats for the US, locations of test centers, test results, business events, and other stuff to help fight this disease.
- Deployed Android and iOS "COVID Access" applications to Google Play Store and App Store (Test Flight).
- Developed multiple web portals from scratch, which are used by 100+ airline companies (American Airlines, Delta Airlines, and Air Canada). These portals provide bulk import of data, generation of different reports (PDF, Excel), big data management.
- Worked on code and functionality enhancements of existing web portals which are used by the biggest airline companies, where they can track employees, tasks, projects, aircraft, engines. The tech stack used included PHP, MySQL, HTML, CSS, JavaScript, and Bootstrap.
- Integrated the Okta multi-factor authentication system into all existing and newly created web portals as a mandatory security feature for all users.
- Remediated code and database structure of all existing web portals to overcome all security holes reported by automatic testing tools (code scanning reports, web application security tests, and more).
Technologies: Ajax, Firebase, Xcode, Android, Hibernate, Web Development, jQuery, Java, Back-end, Full-stack, Bootstrap, JavaScript, CSS, HTML, PostgreSQL, MySQL, Spring Boot, Dart, Flutter, PHPWeb and Mobile Developer
2017 - 2020Freelance Work- Developed a cross-platform (iOS, Android) social network app in Flutter, Spring Boot REST API, and Laravel admin panel. This was used by the Makeover Academy and its students.
- Implemented a generic CMS for eCommerce websites, which is now successfully used by several companies in Serbia.
- Created and tested a secure REST API for webshop sales statistics and reports, invoices, authentication, and more.
- Built multiple webshops using MVC architecture, with the integration of the aforementioned generic CMS and REST API.
- Developed the complete front end and back end of a website that hosts recorded classes for many courses at the University of Belgrade, School of Electrical Engineering, which is extremely helpful to students for preparing and passing exams.
- Built the back end of a web application that connects teachers with students and supports the booking process for private lessons, authentication, and payment.
Technologies: Ajax, Firebase, Xcode, Android, Flutter, Web Development, REST API Architecture, Bootstrap, Back-end, Full-stack, jQuery, JavaScript, CSS, HTML, PostgreSQL, MySQL, Hibernate, Spring Boot, Dart, Java, PHP, Laravel