Denys – PHP, JavaScript, Vue.js

An AI-driven analytics platform for healthcare providers, designed to transform fragmented clinical and operational data into a unified, actionable dashboard for clinics and medical practices. Functional flow:

• Data aggregation — collects KPI data from multiple backend services (appointments, revenue, patient metrics)
• Data visualization — interactive dashboard with 30+ charts showing trends over time and across locations
• Filtering & comparison — flexible period selection (7d, 30d, 90d, custom) with automatic previous-period comparison
• Multi-location analytics — compare performance across different clinics/practices
• AI-powered insights — chat interface using SSE to stream responses and generate insights/visualizations from natural language queries
• Resilience layer — fallback handling, skeleton loaders, and placeholders for incomplete or delayed API responses

• Designed and implemented frontend architecture from scratch, enabling scalable development of a complex analytics dashboard;
• Built 30+ interactive charts using Chart.js with reusable components, supporting multiple data formats and comparison modes;
• Implemented advanced period filtering (7d / 30d / 90d / custom) with automatic previous-period calculations for trend analysis;
• Integrated multiple backend APIs with robust error handling, fallback strategies, and loading states to ensure stable UX;
• Developed AI chat functionality with Server-Sent Events (SSE) for real-time streaming responses and dynamic chart generation;
• Set up CI/CD pipeline and deployment flow using AWS S3 and CloudFront, improving delivery speed and release reliability;
• Established state management with Zustand for predictable and maintainable data flow across complex UI components;

A doctor-led, digitally enabled preventive healthcare platform focused on extending healthspan (not just lifespan). It combines lab diagnostics, AI analysis, and medical consultations into a continuous, data-driven health management system.

Functional flow:

• Data collection - Advanced lab diagnostics (biomarkers across multiple systems)
• AI-powered analysis - Interpretation of metabolism, inflammation, cardiovascular, mental health markers
• Doctor consultation - Video sessions to interpret results and contextualize them
• Personalized plan - Structured 90-day preventive health program
• Ongoing monitoring - Follow-ups + adjustments based on progress

• Delivered core product flows including onboarding survey and multiple health assessments (Blood Pressure, Cognitive, Grip Strength, Mood), using React Native * Expo Router with tRPC + TanStack React Query for typed client/server data flow;
• Implemented and maintained localization (i18next / react-i18next) and UI improvements via NativeWind/Tailwind and shared components, ensuring consistent UX across mobile and web targets;
• Improved release quality and hands-on multiplatform QA, driving pre-release bug fixes and stabilization.

An engaging online platform that immerses rugby enthusiasts globally through a dynamic suite of interactive games, including predictor challenges, trivia contests, and fantasy leagues, designed to deepen fans' connection to the sport.

• Built a responsive Loyalty Hub dashboard using React and TypeScript, integrating MobX stores (managed via Inversify for dependency injection) to display fan progress, achievements, and game entry points, styled with Tailwind CSS for a modern, consistent look;
• Identified legacy MUI components in the Fantasy, Trivia, and Predictor games, and refactor them to use pure Tailwind CSS, ensuring consistent styling and reduced bundle size, while maintaining TypeScript type safety for props and state;
• Implemented a team creation interface for the Fantasy Game using React and TypeScript, leveraging MobX for state management (injected via Inversify) to handle player selections and real-time fantasy points/XP updates, styled with Tailwind for responsiveness;
• Used React with TypeScript to build dynamic progress trackers (e.g., progress bars, leaderboards) in the Loyalty Hub and Fantasy Game, integrating MobX for reactive state updates and Tailwind for sleek, animated visuals;
• Developed a single-page Trivia Game interface using React and TypeScript, fetching questions via an API provider (injected with Inversify), using MobX to manage quiz state, and applying Tailwind CSS for animated correct/incorrect answer feedback;
• Created prediction forms for the Predictor Game using React, TypeScript, and Tailwind CSS, with MobX stores (injected via Inversify) to manage user inputs and display real-time match prediction outcomes with minimal latency;
• Set up Sentry to monitor and log frontend errors across the Loyalty Hub, Fantasy, Trivia, and Predictor games, using TypeScript to ensure proper error typing and leveraging Vite’s build system for optimized error reporting in production;
• Utilized Vite’s fast build and hot module replacement to streamline development of React components, ensuring quick iteration and optimized production builds for the entire platform, with TypeScript ensuring type safety throughout.

A Big Data analytics platform that aggregates geolocation data from individuals across the United States. The data is sourced through third-party services that collect geolocation information from various apps, which share this data with external providers. While the platform's apps are interconnected solely via a shared backend, they collectively enable powerful insights and analytics.

• Redesigned the project to match the new design, improving functionality and user interaction;
• Refactored legacy code, transitioning from VanillaJS/jQuery to Vue 3, enhancing architecture;
• Implemented Pinia for state management, improving reactivity and consistency;
• Refined props handling to ensure proper use of reactive properties in Vue;
• Updated charting library to Chart.js for modern data visualization;
• Integrated Tailwind CSS, PostCSS, and DaisyUI for flexible styling and faster component prototyping;
• Added PDF export functionality with HTML2Canvas and jsPDF;
• Implemented drag-and-drop functionality with Vue-Draggable-Next for better UX;
• Improved routing with Vue Router (in progress);
• Converted components to Vue 3 Composition API for better maintainability;
• Refactored components for improved structure and performance;
• Optimized build and development processes, reducing build time from 15s to under 1s;
• Resolved Hot Module Replacement (HMR) issues, enabling faster development;
• Replaced outdated libraries and optimized frontend code for better performance and scalability.

This is a mobile learning application that provides a highly satisfying, interactive user experience to help you reclaim what it means to think for yourself. The core idea is evaluating posts and learning to spot misinformation. Features:

• Creating posts / Social Network
• Chats
• Voting
• Reports

• Built the server-side logic, database management, and APIs that handle data processing, storage, and retrieval;
• Implemented new features and functionalities as per the project's requirements;
• Created and managed RESTful APIs endpoints to facilitate communication between the front-end and back-end components of the application;
• Conducted unit testing, integration testing, and end-to-end testing to ensure the quality and reliability of the application.

This is a trusted information portal for Nigerians. It offers information about personal development and business growth opportunities. It features the following:

• Listing products
• Information Portal
• Marketplace
• Integration with local business
• Create / Find Events
• Creating paid Articles
• Affiliate Marketing
• Club Connect programs for subscribers
• Ads

• Built and maintained the server side of the website;
• Designed and managed the database structure, ensuring data integrity and optimizing database queries for better performance;
• Created and managed RESTful API endpoints to facilitate communication between the front-end and back-end components of the application;
• Implemented new features and functionalities as per the project's requirements.

A retail and wholesale warehouse of spare parts, batteries, oils, car care products, tools, and accessories.

• Performed activities to optimize the website for search engine optimization;
• Ensured website quality, performance, and reliability;
• Customized website layout/user interface using HTML, CSS, and JavaScript standard practices;
• Took part in various phases of SDLC, including design, analysis, development, testing, and long-term support.

A Certified Training Center that aims to provide high-quality services for training and consulting in software development.

• Followed a full cycle of application development (most of the apps are part of NDA).
• Managed both back-end and front-end aspects of the development process.
• Profiled E-commerce projects.
• Managed databases of MySQL, MongoDB, and Firebase.
• Created dynamic web apps using PHP and MySQL to suit individual client needs.
• Supported long-term existing projects and sites.
• Developed front-end UI/UX designs.
• Took part in various phases of SDLC, including design, analysis, development, testing, and support.
• Developed 1C Bitrix project.

Ukrainian brand of automotive oils that have been successfully winning the trust of consumers around the world for over 20 years.

• Managed site architecture, strategy, and planning.
• Conducted website performance tests.
• Interacted with 3rd party APIs.
• Built and developed online payment processes.

Online marketplace brand that sells Ukrainian footwear and accessories.

• Developed front-end UI/UX designs.
• Refactored legacy code.
• Supported new features and functionality.
• Managed databases of MySQL.
• Executed security measures such as firewalls and encryption.
• Completed full redesign of existing website to improve navigation, enhance visuals, and strengthen SEO rankings.

A Ukrainian pawnshop network.

• Developed a network from scratch.
• Configured DNS and SSL certificates.
• Built payment system using RESTful APIs, contributed back-end development experience and collaborated on multiple APIs crucial to functionality.
• Managed NoSQL and SQL databases.