rowkash

• Architected and deployed a decentralized escrow system on the TON blockchain using the Factory-Child smart contract pattern to automate secure, monthly rental payments and security deposit holdings • Implemented complex smart contract logic handling USDT Jettons, payload validation, dynamic state tracking, automated fund forwarding, and a multi-party dispute resolution mechanism • Implemented unit and integration tests for core smart contract logic, focusing on payment flows, validation rules, and state consistency • Integrated KYC/AML verification via SumSub, including access token generation and webhook handling for user verification status synchronization • Integrated MinIO (S3 storage) for secure image upload and management for property listings • Integrated geolocation and address lookup functionality using OpenStreetMap services • Configured structured application logging using Pino to improve debugging and centralized log collection workflows • Implemented automated document generation workflows, populating contract templates with verified user data and converting generated DOCX documents to PDF format

• Implemented backend features for advertising management platform, including RBAC-related functionality, REST API endpoints, and multilingual (i18n) support • Integrated third-party advertising and analytics platforms (social media and ad network APIs) for conversion tracking and campaign analytics • Configured Sentry-based error tracking and performance monitoring across microservices • Participated in migration of statistical data from MariaDB to MongoDB and developed synchronization flows with a ClickHouse-based analytics microservice • Implemented unit, integration, and E2E test suites using Jest

• Implemented backend features for an e-commerce marketplace platform, including product management, user interactions, and marketplace workflows • Optimized MongoDB queries using aggregations, indexing strategies, and data structure improvements, reducing database load and response times • Implemented Socket.IO-based voice calling functionality in a clustered Node.js environment • Analyzed and resolved backend performance bottlenecks, eliminating excessive database operations and improving overall system responsiveness • Fixed caching-related issues and improved cache consistency across application services • Diagnosed and resolved issues across third-party integrations and media-processing services, including FFmpeg, Google Translate, and Sharp