Vasyl – Node.js, PostgreSQL, MongoDB

Stigg.io is headless monetization and pricing orchestration platform. It acts as a dedicated middle layer between a software product and a billing system (like Stripe), allowing product and engineering teams to easily manage paywalls, feature entitlements, usage-based metering, and customer self-serve portals without hardcoding changes.

• Designed and delivered AWS Marketplace and App Store integrations, extending platform reach to new enterprise.
• Maintained and improved Stripe and Zuora billing connectors, handling subscription lifecycle events and payment flows.
• Enhanced the DataExport integration, improving visibility, data availability and reliability for downstream analytics.
• Participated in on-call rotations to support production systems and resolve incidents in a timely manner.

Web and mobile platform for interacting with multi-chain cryptocurrencies and NFTs.

• Contributed to breaking a monolithic service into microservices.
• Architected and built a transaction service with admin panel for EVM blockchain interactions, including full transaction status lifecycle management
• Integrated the Moralis API for handling NFT data.
• Built a coin service to manage cryptocurrency historical data and account balances, integrating CoinGecko API and QuickNode API.
• Contributed to services related to the Invisible Wallet functionality.
• Implemented login functionality via Apple OAuth.
• Built an auth library for JWT verification and published it via GitHub Packages.
• Integrated linting tools and static application security testing (SAST) tools into the CI/CD pipeline.
• Created LLM-as-a-Judge tests for responses generated by the RAG system.

An application that collects and aggregates information about companies. It searches companies' information in several vendors, merges it, and allows to generate reports with company profiles and its member's data. Know Your Business (KYB) service.

• Developed core part of the application;
• Developed API to generate PDF, ZIP files;
• Integrated telemetry services;
• Developed pages to show company-related information;
• Released application versions.

A collaboration platform that allowed organizations to manage their documents and interact with customers and government services.

• Designed, developed, documented, and supported new microservices;
• Tested and troubleshot the application;
• Transferred functionality from .NET monolith server application to Node.js microservices;
• Developed application for generating microservices scaffold;
• Integrated third-party services;
• Updated CI/CD flows;
• Released platform versions;
• Mentored team members.

The system serves butcher shops and other produce stores. It has a webshop platform that allows configuring online ordering. It has an order kiosk that helps customers easily and quickly enter their orders in a store. It has software for the configuration and generation of bar codes. Also, it has a dashboard for handling charges, customers, etc.

• Developed core part of the new version;
• Integrated Zebra printer;
• Implemented service for handling barcodes structure (via ZPL language).

The platform provides a game where participants assemble virtual teams composed of proxies of real players of professional soccer leagues. These teams compete based on the statistical performance of those players in actual games.

• Developed back-end features;
• Developed Twitter bot;
• Developed admin panel features on front-end and back-end;
• Integrated monitoring system with Slack bot.

The platform helps businesses customize a last-mile delivery solution to provide the best service to their customers. On the other hand, it helps the courier community to grow their business by picking up shifts, scheduled jobs, or on-demand deliveries.

• Developed microservices for mobile API;
• Developed microservice for bundling orders in shift run (estimate and bundle food orders into driver routes);
• Developed microservice for providing external API usage;
• Implemented integration with Google Directions API.

Mobile application that interactively provides the leading services in order to ease the life of Telecommunications Regulatory Authority customers.

• Developed core part of the system;
• Developed mobile API;
• Integrated with Microsoft Dynamics CRM;
• Set proxy library on C#;
• Developed markup meta-language for mobile dynamic views;
• Developed admin panel;
• Released application.

Mobile application that provides kinds of games that are based on beacons and connected to mall stores. It allows you to accumulate loyalty points, find great deals, redeem awesome prizes, and participate in fantastic competitions.

• Developed core part of the system;
• Developed mobile API;
• Developed admin panel;
• Developed a points system to receive and redeem prizes;
• Implemented integration with beacons.