Nikola Vasović

I significantly contributed to developing Innov8's iScreen app, a medical tool for early autism detection built with Flutter. My role focused on ensuring a seamless user experience, robust back-end connectivity, and enabling direct interaction between medical experts and parents. Notably, the app rapidly generated digitally signed diagnostic PDFs, streamlining the diagnostic process and reflecting Innov8's commitment to transforming autism care.

I translated design ideas into an intuitive interface and collaborated closely with Innov8's CTO to establish reliable front-end-back-end communication.

KEY FEATURES
• Streamlined user registration for providers and patients
• Secure credential verification for providers' licenses and diplomas
• Simplified child registration for parents with accessible documents and media uploads
• Efficient provider-patient matching for optimal healthcare connections.
• Enabled digital diagnosis creation with signed PDFs, advice, and prescriptions
• Integrated push notifications for timely updates on diagnosis completion

The app was successfully released to App Store as MVP and was tested and refined based on feedback from medical experts and patients.

QuatuorMD is an application available across the web, iOS, and Android platforms, exclusively designed for clients of the QuatuorMD clinics in Canada. The app empowers patients to monitor their metabolic health and provides convenient access to content and information about the Quatuor clinics. With user access managed through the clinic's CRM, the app ensures a secure and personalized experience, eliminating the need for 3rd-party authentication services.

As a Flutter developer, I focused on turning Figma's design ideas into mobile and web apps. I also handled the behind-the-scenes work, connecting the app to Firebase Auth, Firestore, Dynamic links, and custom AWS back end. To make things run smoothly, I made Firestore work better by using offline cache and custom ways to store data, which led to significant cost reduction of cloud services.

Also, I integrated advanced features like Firebase Phone validation and MFA for admin users, enhancing security while retaining convenience. I expanded accessibility through a responsive web platform using Flutter's capabilities, serving clients and professionals. Real-time charts and score updates via listeners, sockets, and streams elevated user engagement.

UnfoldMD is an innovative AI-driven (OpenAI's GPT-4) medical chatbot designed to provide healthcare professionals with accurate and validated responses to medical inquiries and as a team member, I was crucial in developing UnfoldMD's mobile interface and front-end business logic using the Flutter framework. At the same time, my teammate ensured that the information delivered was precise and relevant using vectorial databases.

Additionally, I collaborated with the teammate to implement a feature that lists credible sources for every answer, enriching the user experience and enabling further exploration of the subject matter. Also, I created UnfoldMD's Inbox feature, which helped shape the intelligent algorithm that tailors personalized articles based on users' search queries. This feature aims to keep healthcare professionals well-informed and up-to-date within their field.

I use my Flutter proficiency to efficiently minimize cloud expenses by employing offline caching for accessing Firestore Cloud. I've established a well-structured architecture, secure rules, and integrated real-time chat listeners with standard indicators and advanced bot features.

An iOS application developed using the Flutter framework, which is designed to be used by patients who have heart diseases to help them adapt their lifestyle to feel better. The app doesn't have an associated 1st-party back end; it uses Firebase and its Cloud Firestore to store content in a NoSQL way. I worked as a solo front-end developer, defining app architecture from scratch and focusing on its robustness. Hence, its front end has a "mini back end" in separate Flutter modules.

The look and feel of the app rely on the Figma prototype. The app's core is the Get design pattern and state management system (Pub.dev, packages, and get), and it's very suitable for creating reusable and generic portions of the code, which can be implemented easily in some other application environments. The app is accessible only to subscribers registered into the RevenueCat back end using the Apple Store in-app purchase mechanism.

After subscribing, users can access health tests, daily and weekly tasks, and health data (integrated Apple Health Kit). Based on their daily activity, the app calculates scores using complex calculations to present the actual state of users' bodies.

Boost website is one of the samsung.com services, which is available in the United Kingdom and Ireland as two separate web applications using the common back-end. The project was designed to detect users' mobile devices - https://samsung.com/uk/boost and https://samsung.com/ie/boost pages, to serve them partner offers and promotions by generating voucher codes. Official partners generate voucher codes - Deezer, Calm, YouTube Premium, Readly, Google Play Pass, Google Play Points, Adobe Lightroom, Disney+, Fiit, and Antstream.

The app's front-end was developed using React framework, and the back-end was implemented in Node.js, while MongoDB is used on the database side. I led a team of two developers and a QA engineer as a technical project manager with some support in development and deployment.

Some of the features are:
• Samsung Account Social Sign In
• ReCaptcha Enterprise
• Device detection (eligible devices - S21 Series, Flip, Fold, Tab S7, Desktop)
• Country detection (used third-party API - https://ipdata.co/pricing.html)
• Integration of new partners (Disney+) and their voucher codes

Back-end deployment requires Kubernetes and Helm usage; Front depends on Adobe Experience Manager.

A social app developed by Flutter, allows groups to decide where they want to eat and it utilizes a gesture-based user interface to find nearby US restaurants and bars. The idea behind the app is to remove the back-and-forth discussions between groups by automating the decision-making process with a unique preference system.

I was responsible for implementing a complete Flutter app based on the Invision prototype that the designer provided. I collaborated with a back-end developer who prepared an API for which I integrated endpoint calls and data flow on the front end.

The app uses a location feature to select an area of interest for a group, a smart push notification system that keeps the app synchronized in real time, and deep links that allow new users to quickly join the eating decision process.

I implemented a lot of animations on different screens, which makes the gesture-driven interface more powerful. I also deployed the beta version of Android and iOS apps in the Play Store and App Store.

A customer website and admin panel feature updates for the biggest cryptocurrency exchange in Serbia. I was responsible for the back-end development of APIs (in Laravel) used by the customer website, which was developed in parallel by another team member. Also, I had full-stack tasks on the admin panel, which has MVC architecture—the back end built in FuelPHP framework and the front in HTML, CSS, and JavaScript.

The tasks which I worked on were related to two big features:
1. Automatic handling of weekly transaction limits and user risk levels
2. Creation of secure Crypto and Fiat wallets integrated with 3rd-party systems

These features had related tasks that needed to be implemented on the admin panel and customer websites. When the 1st feature was implemented, it reduced the manual work operators previously performed. It supported uploading various personal documents used and processed by finance institutions of the countries where the site was deployed (Serbia, North Macedonia, and Australia).

Wallet development upgraded company, which only had Crypto-Fiat centralized exchange feature to the trading ecosystem with personal wallets, where customers can hold Crypto/Fiat. Implemented MFA/reCAPTCHA.

A Flutter application developed for the biggest food retail company in Serbia (MAXI—Maxi.rs), which is part of the vast global retail group—Ahold Delhaize (Aholddelhaize.com). The app aimed to perform online giveaways through puzzle games and augmented reality features. I was responsible for front-end development while another team implemented API endpoints in parallel.

The application consists of an integrated puzzle game built using the Unity framework. Besides that, there is an interactive map filled with markers on the territory of Serbia, generated by a specific algorithm that considers the user's location and the location of all retail stores in the country. Map markers represent gift boxes that can be collected using the augmented reality feature. Gift boxes are used to get giveaway products from stores and get additional lives for the game.

From the additional features, the app used Firebase Dynamic Links and push notifications. I provided weekly builds to be tested by the end company using Firebase Distribution and Test Flight.

A web platform that sells guest posts on high authority websites with solid metrics and traffic stats. These websites cover various niches, including finance, education, gambling, travel, health, etc. Unlike some other link-building providers, Authority Builders provides links from trusted, real-ranking websites.

I am the head of the tech team, responsible for leading a group of six software engineers. My team works together in the office and provides remote outsourcing for Authority Builders Co. Besides managing the team, I work on core system stuff and collaborate with project managers, sales, finance teams, and founders.

The project consists of four web portals organized as separate web applications—customer, administrator, blogger, and content writer portals. Web applications based on MVC and API architecture use the CodeIgniter framework. My team is developing new features, improving existing functionalities, code optimization, front-end upgrades, and more. The most important part of the back-end stack is developing and integrating payment systems (PayPal, Stripe APIs), directly affecting Authority Builders Co's income.

As a full-stack developer, I took charge of vital admin platforms for top global airlines. My role involved adding new features, ensuring security based on frequent tests, and managing daily tasks.

I focused on improving the platforms by creating efficient features for tracking aircraft conditions and parts. Much of my work was maintaining tight security through regular penetration testing and implementing Okta Multi-factor Authentication (MFA) for added protection.

My routine included handling PDFs, CSVs, and generating reports essential for airline operations. I also managed internal tasks, promoting smooth communication across teams.

I utilized custom PHP and VanillaJS to build responsive web apps tailored to the airlines' unique needs. This approach helped in creating user-friendly and efficient solutions.

A cross-platform app was developed using the Flutter framework for the Dart programming language. The app aimed to connect subscribed clients with their favorite personal trainers via online video workouts and exercises during the lockdown caused by the COVID-19 virus.

I was responsible for all parts of this project, including the Flutter app, Laravel API (MySQL database), and Laravel MVC admin panel. I worked as a developer who needed to fix all design and functionality issues made by developers who worked on this project from the start. I also redesigned and reimplemented all parts of this project, including refactoring code structure and creating reusable design patterns. Implemented social login, subscriptions, search, feed, favorites, and profile functionalities.

I localized both sides of the app (front-end and back-end localization) to Arabic and English. I also deployed test versions of Android and iOS apps to the Google Play Store (production) and App Store (test flights).

This web application offers users with a non-Samsung device to buy its Samsung alternative in the same class (main targets are Apple and Huawei). It was developed for the Adriatic region. Its core feature is the device brand and model recognition algorithm based on user-agent and third-party libraries. This system has an admin panel with content management features, where the admin can define products, offer contents, partners, and target groups for detection. Based on the detected target group, the relevant competitor's website is rendered, and the user can be redirected through it to the partners' shops. Partners are lead technical retailers in Serbia.

I led a team of two software engineers who delivered the product, and I was responsible for communication with the client and partners. Competitors' platform offers its API for redeeming voucher codes and tracking sales on partner's websites. Partners can sign in to their admin panel and track their vouchers.

Project is implemented in Laravel (MVC + API) with front-end stack - HTML, CSS, JavaScript, Bootstrap. MySQL is used as a database server. I set up CI/CD with Docker and self-hosted Gitlab.

This application, which has Flutter-based mobile application as well, communicates with 3rd-party APIs that provide COVID-19 stats for the US, locations of test centers, test results, business events, QR code ticket scanning, geolocation features, and other stuff to help fight this disease.

As a full-stack developer, I implemented it from scratch. I was also responsible for the Flutter app, which communicates with the REST API, which I implemented using Spring Boot in Java and PostgreSQL database, and 3rd-party APIs for tracking virus statistics. I was also responsible for deploying the app to Google Play Store and App Store (test flight).

A fork of the SuiteCRM system with many new features implemented to satisfy requirements for managing and presenting data from the warehouse of Payment 1 loan company (Payment1.com). All extensions to the existing CRM system were developed using pure PHP programming language and MySQL database (back end), and data representation was implemented using standard front-end tech stack —JavaScript, HTML, and CSS.

I was responsible for full-stack development and DevOps on the CRM side. I communicated intensively with the tech team, which maintained Payment 1 data warehouse storage and their presentation site.

ACHIEVEMENTS
• Created automatic Bash script for daily importing of users, payments, and loans from the data warehouse to the newly created CRM system (Bash script with periodical SFTP connection).
• Wrote high-quality MySQL raw queries to extract all necessary stats from the CRM to present them to the employees using it.
• Tracked user behavior with a specific algorithm, monitored their activity and average time spent and recorded sign-up conversions from various referrers.
• Set up an email server to support campaigns.

• Developed a cross-platform (iOS, Android) app using the Flutter framework and the Dart programming language.
• Built a back-end REST API implemented using Spring Boot in Java. The data layer is accessed via PostgreSQL.
• Implemented a Firebase API (for authentication) and Google Cloud Services (Firestore and Google Cloud Storage).
• Developed an admin platform in PHP using the Laravel framework, which connects to the same PostgreSQL database.

I was responsible for all parts of the project (excluding app design and deployment). The mobile app includes a subset of standard social network features (like a simple version of Instagram), including posts, likes, comments, followings, chats, and notifications. I also implemented additional functionalities like makeover courses and lessons (that content is uploaded through the admin panel). I used Google Cloud Storage to store social network media content (videos, images, and lessons). The chat and notification subsystem was implemented using Google Firestore with Firebase-based user authentication.

I implemented a decentralized web platform for secure file sharing between users.

It's based on Ethereum smart contracts and the InterPlanetary File System (IPFS). I built the front end using the JavaScript API for the Ethereum blockchain and IPFS. I executed the back-end code only within the smart contracts implemented using Solidity. A central server doesn't exist in the application at all. That system has a futuristic concept for file sharing without the presence of a third-party server.

I connected with Ethereum network using the Metamask extension for the Google Chrome browser. The main innovation, which the implementation of this system provides, is the protection of file content located on the IPFS network. The files are protected using symmetric-key cryptography, and related keys for protection are encrypted with public/private key pair.

I developed that system as an individual project, meaning I was responsible for the front and back end of this decentralized web application.

I implemented an admin sales management platform for sophisticated and semi-complex web stores.

It allows the manipulation of products, categories, brands, coupons, vouchers, invoices, suppliers, orders, etc. In addition to selling, there is also an option to add new text articles to the company blog. Various statistical parameters are also available (based on sales trends), stock balances can be tracked, as well as the distribution of products in any single shop can be tracked.

It can be integrated into any client's website because it is entirely independent of the particular sales company. There are also multiple user groups in the system with different degrees of privileges. We built it for the Serbian market, and several online sales companies currently use it. As the platform facilitates a large volume of sales, so much of the paperwork is automated, which saves a significant amount of time for shop administrators.

The platform was implemented using the Laravel framework and MySQL database. The front end was built using the Bootstrap library and standard technologies like HTML, CSS, JavaScript, and jQuery.

Above all, the project is intended to be a website and webshop of a company that has been a leading seller, importer, and distributor of audio equipment in Belgrade for 20 years. The company represents only world-renowned audio brands and is the exclusive importer for the Republic of Serbia. It also specializes in all facilities where music is an indispensable element of everyday events.

It is an advanced eCommerce website implemented in the Laravel framework using a MySQL database as data storage. The site has an MVC architecture, and I built the front end using the Bootstrap library and standard technologies like HTML, CSS, JavaScript, and jQuery. The developed website includes several different user groups, as well as an admin platform through which it is possible to manage the web store's content.

I was responsible for the implementation of the entire website.

I developed the entire front and back end of a website that hosts recorded classes for many courses at the University of Belgrade, School of Electrical Engineering.

The site is beneficial to students in their exam preparation. The audio recordings are divided by university levels, sections, and exam titles, and they are playable through a website-embedded audio player. All audio files were stored with compression on a central server, and we used a database to index them.

Along with implementing the MVC architecture in the app, I built the back end using the Laravel framework and the front end using JavaScript, jQuery, Ajax, HTML, CSS, and Bootstrap.