Roman – Golang, Kubernetes, AWS

It's an iGaming platform.

• Ensured system reliability and scalability through efficient database design, distributed caching, and message-driven communication.
• Delivered 30+ successful payment provider integrations, expanding the platform's global coverage and transaction capabilities.
• Streamlined payment processing architecture in compliance with PCI DSS standards.
• Reduced transaction error rates from 0.04% to 0.01% and decreased security vulnerabilities by 35%.
• Collaborated with cross-functional teams (front-end, product, QA, DevOps) to define requirements, refine architecture, and deliver features on time.

It's a company that specializes in digital out-of-home advertising.

• Spearheaded migration of a legacy monolith to microservices, cutting feature release cycles from ~2 weeks to a few days.
• Redesigned and optimized core APIs powering DOOH workflows, boosting request throughput by 40% and lowering average latency by 30%.
• Implemented comprehensive automated testing (80%+ coverage) across unit, integration, and E2E layers, reducing production bugs by ~50%.
• Streamlined ad placement & booking flows, improving overall platform efficiency and driving 25% faster campaign onboarding for clients.

It's a trading platform based on the ETH blockchain.

• Built blockchain indexers from scratch to process and normalize high-volume on-chain data, enabling near real-time analytics and mirroring.
• Developed database architecture optimized for blockchain transaction data, improving query performance by ~40% for trade history lookups.
• Implemented complex routing logic to mirror trades of top-performing wallets, ensuring transaction integrity and reliability across thousands of replicated trades.
• Delivered secure, gas-optimized smart contracts, reducing operational costs by ~25% per transaction.

It's a local event discovery platform for residents, digital nomads, and tourists in Ericeira, Portugal. The product aggregates cultural, social, and lifestyle events into a single platform, making it easy to discover what’s happening in your local area.

• Built and maintained the back end in Golang, designing REST APIs and database schemas.
• Developed the frontend using React + Vite with a mobile-first approach.
• Implemented event listings, categorization, and date-based filtering.
• Designed the system with scalability and future monetization in mind (organizer tools, vouchers, promotions).
• Took ownership of architecture, technical decisions, and product evolution.