Hands-on CTO / Principal Engineer

Hands-on CTO / principal engineer with 20+ years in software engineering. Technical co-founder, CTO/CPO, architect, fractional product owner, and engineering lead. Works best at the intersection of architecture and implementation: designing data-heavy systems well, then staying close enough to the engineering to keep latency, operability, failure modes, and tradeoffs grounded in reality. Selected work includes fractional lead/architect for a ground-up KPI platform rewrite for a company that later exited for €10M, CTO/CPO for a crypto/data product involving live matching of 1M+ complex dynamic slices against continuous on-chain/off-chain metric streams with high-throughput and near-real-time latency, and ClickHouse-backed worker pipelines processing billions of rows/day. Looking for freelance, contract, fractional CTO, principal engineer, technical lead, or data engineering work. Best fit for backend-heavy products, analytics/data infrastructure, complex internal tools, low-latency pipelines, or early-stage teams needing a senior person with both breadth and depth.