Projects

Selected backend, full-stack, and API-focused projects.

Billing Platform Demo

Full-stack billing-focused application with a deployed frontend, Spring Boot backend API, and PostgreSQL database.

The project supports customer creation and retrieval through REST API endpoints. The frontend is deployed on a custom domain, the backend runs on Render, and the database is hosted on Neon PostgreSQL. Database schema changes are managed with Flyway, and database credentials are stored securely through environment variables.

Tech: Java, Spring Boot, PostgreSQL, Flyway, REST API, Render, Neon, JavaScript

Live Demo: billing.nikitsya.dev

Frontend Repo: GitHub frontend repository

Backend Repo: GitHub backend repository

Backend API: billing-platform-api.onrender.com

Supermarket Store System

Java client-server application for managing supermarket departments, products, inventory data, pricing, and images.

The system exposes its operations through a structured JSON protocol over TCP, stores persistent data in MySQL, and handles multiple clients concurrently using a server-side thread pool. It includes DAO-based persistence, image upload and retrieval, metadata-only queries, structured success and error responses, and automated tests.

Tech: Java 17, Maven, MySQL, JDBC, Jackson, TCP sockets, ExecutorService, JUnit 5

View on GitHub

World Cup 2026 Mexico Guide

Interactive travel guide web application for tourists visiting Mexico during the FIFA World Cup 2026.

The application uses Google Maps, Places, and Directions APIs to explore host cities, stadiums, nearby places, and route planning. It also integrates live weather data, currency conversion, responsive layouts, and PWA support with a service worker for offline static assets.

Tech: Vanilla JavaScript, ES Modules, HTML, CSS, Google Maps API, Google Places API, Google Directions API, Open-Meteo API, Frankfurter API, PWA

View on GitHub