Andrii Shavalo

Hi! I am a Full-Stack Developer with 2+ years of commercial experience in building scalable web applications. I specialize in the TypeScript ecosystem: Next.js for the frontend and NestJS + PostgreSQL for a reliable backend. I transform slow integrations into fast, high-load resilient systems, focusing on actual business needs.  

How I help businesses (My cases):

• E-commerce & Shopify integrations: Optimized catalog synchronization for Shopify stores (over 54,000 products), reducing processing time by 83% (from 6 hours to 1 hour) through smart data filtering (GigaB2B API) and process automation via n8n.  

• Artificial Intelligence (AI) integration: I implement AI solutions to automate processes and improve user experience. For a large B2B/B2C platform, I developed an AI assistance and automated feedback system, significantly expanding the product's capabilities.  

• SaaS, Telegram Mini Apps & Multi-Tenant architecture: I design scalable microservice platforms. I have experience developing systems where business owners can manage their stores via a Telegram Mini App with dedicated subdomains for clients.  

• High-load booking systems: Engineered a booking engine with distributed locking via Redis, completely solving the issue of double bookings during peak loads.  

• Payment pipelines (Stripe, Monopay, LiqPay): I set up fault-tolerant payment processing (Stripe webhooks with idempotency, integrations with Monopay and LiqPay), smoothly handling hundreds of transactions per month with zero financial discrepancies.  

• Geospatial (GIS) platforms: Built complex interactive maps (Mapbox + Turf.js) with satellite API integration (EOSDA) for real-time monitoring and facility management.  

Tech Stack:My core skills include React, Node.js, Redis, RabbitMQ, BullMQ, working with AWS, SendGrid, and developing offline-first PWA applications. I handle the full development cycle — from database architecture to final deployment (Docker, Railway, Vercel). I guarantee clean code, strict adherence to deadlines, and a deep understanding of your product's business logic. I would be glad to discuss your project and propose the optimal technical solution!