w3rlock

Led a cross-functional team of 25+ engineers (backend, frontend, mobile, QA), personally contributing to Go/Python development (~30% of time writing code) • Managed delivery: sprint planning, cross-team dependency coordination, design review, code review, release quality control • Conducted weekly 1:1s, performance reviews and mentoring programs — grew junior engineers to mid-level • Collaborated with PM on technical discovery: hypothesis validation, feasibility assessment, product roadmap shaping before development

Responsibilities: • Designed overall system architecture: microservice decomposition, data flows, API contracts and blockchain integration patterns • Built the matching engine for invoice trading with configurable matching rules and settlement logic • Implemented blockchain integration services and smart contracts for invoice tokenization and verification • Oversaw entire team (2 backend, 1 frontend, 1 QA), conducted code reviews and design reviews • Collaborated with PM on technical discovery: decomposing business requirements into technical specs and sprint plans

Project Description: Non-custodial crypto payment gateway enabling merchants to accept crypto deposits across 7 blockchain networks. Each network had a dedicated microservice handling deposit address generation, transaction monitoring and settlement routing. Role: Solo Backend/Blockchain Engineer (client had their own team) Responsibilities: • Designed and implemented independent deposit services for each blockchain network: Ethereum, Solana, TRON, Polkadot, XRP, Litecoin and Cardano • Built deposit address generation, transaction monitoring and confirmation tracking for each network • Implemented smart contract integration for EVM-compatible networks (Solidity) and SPL token handling for Solana • Ensured fault-tolerant deposit processing with retry logic and reconciliation across all supported networks

Full-featured centralized crypto exchange for a European client with MiCA license. The platform supported spot trading across multiple blockchain networks (BTC, EVM-compatible, XRP, Solana) with a real-time matching engine, multi-chain wallet infrastructure and automated deposit/withdrawal processing. Responsibilities: • Designed and implemented the matching engine and order book in Go, optimized for high throughput and low latency • Built multi-chain wallet infrastructure for BTC, EVM-compatible networks, XRP and Solana — including deposit detection, withdrawal processing, hot/cold wallet management • Developed REST/gRPC APIs for all trading operations, user management and internal services • Implemented fault-tolerant transaction processing with Kafka streaming for deposit/withdrawal reconciliation • Owned security architecture: key management, signing processes, secured transaction pipelines • Conducted code reviews, design reviews for new features, mentored backend engineer

Project Description: Blockchain outsourcing company. Led full-cycle development of blockchain projects for external clients. Role: Project Manager / Tech Lead Responsibilities: • Led blockchain project development from requirements gathering to release: requirements, architecture design, team coordination, release management • Conducted Agile ceremonies (Scrum, Kanban), daily standups, code/design reviews for teams of 3–7 engineers • Designed project architectures and wrote technical specifications for smart contracts and DeFi projects

Project Description: Built the company's IT department from scratch: defined service offerings, hired developers and managed the client project pipeline. Role: Developer → Head of IT Department Responsibilities: • Transitioned from hands-on development to building and leading the IT department • Conducted interviews, hired developers, defined service offerings, managed project delivery to clients • Led development of internal and client-facing web applications