Greater Hradec Kralove Area
I turn ambiguous technical visions into hardened production systems. I write the architecture docs, define the roadmap, and join the team to build and scale. At Protocol Labs, I led the protocol design for SPARK. Our two-engineer team built and operated a network of 15,000+ daily active permissionless nodes, resulting in a 15x improvement in Filecoin retrieval success. I foster engineering cultures that prioritise speed without fragility. By establishing fast feedback loops and grounding AI-assisted development in TDD, I help teams ship at high velocity while keeping production regressions and maintenance costs low. My background in distributed systems is rooted in foundational open-source work, including major contributions to Node.js core and leading the LoopBack framework at IBM. I build primarily with TypeScript/Node.js, Rust, and PostgreSQL. I thrive in remote-first, distributed environments.
Co-founded Space Meridian. Managed and mentored a distributed team of 3-4 engineers. Led hiring, designed interview structure, onboarded new engineers. Filecoin SPARK & Checker Network Continued leading development of Filecoin SPARK, Zinnia, and the Filecoin Station network. • Scaled the network to >100k registered users, >15k daily active nodes, and ~36M retrieval checks daily • Built dozens of Grafana dashboards and alerts for network observability • Reduced infra bill by ~25% through database right-sizing and indexing; increased testing throughput 4× (100 → 400+ deals per round) • Authored design documents covering system architecture, protocol specs, security designs, and operational runbooks • Co-authored the Checker Network litepaper Impact: drove a 15× improvement in the retrieval success rate of content stored on Filecoin. Technologies: Rust, TypeScript, Node.js, Deno, PostgreSQL, Electron, libp2p, IPFS, IPNI, Solidity smart contracts, Grafana, Fly.io FilBeam — incentivized CDN for Filecoin • Authored the concept for FilBeam — shifting from SPARK's measurements based on synthetic traffic to measuring real user traffic through an incentivised CDN. • Led the initial push and the team shipped the first MVP in two weeks. • Drove IPFS retrieval integration: collaborated with teams across the ecosystem to understand retrieval paths and client needs, authored a design spec with incremental milestones, scoped a feasible plan for the LabWeek deadline • Created space for other engineers to step up and design major features like egress-based payments • Presented FilBeam at DePIN Day (live-streamed by CoinDesk) and multiple Filecoin Developer Summits • Connected teams across the ecosystem (FilOz, Curio, Venus, IPNI) to drive alignment on retrieval infrastructure Technologies: Cloudflare, TypeScript, IPFS, Filecoin, Solidity smart contracts, Grafana
Built core infrastructure for Filecoin's retrieval verification ecosystem, operating across multiple open-source projects with thousands of active participants. Zinnia — JavaScript/WASM runtime (Rust) Led design and implementation of Zinnia, a sandboxed runtime for Filecoin Station modules built on Deno and Rust. Shipped public alpha in 5 weeks — from research through architecture decisions, libp2p integration, and cross-platform release engineering (macOS code signing, Windows builds). Published Architecture Decision Records evaluating runtime options (Wasmtime vs Deno vs Wasmer vs Docker) on GitHub. Filecoin SPARK — decentralised retrieval verification protocol and network Designed and built Filecoin SPARK, a protocol and distributed network of nodes that verify whether content can be retrieved from Filecoin storage providers. Led protocol design and implementation of the network — checker nodes, orchestration layer, and backend services — driving cross-team alignment with IPNI, Bedrock, and Curio on content discovery and fraud detection. Co-authored the Threat Model (13 client-side + 3 SP-side + 5 collusion attack vectors). Authored ecosystem-wide specification proposals defining retrieval attestations and retrieval checking requirements. Created roadmap documents breaking multi-month projects into incremental milestones. Quantified impact: • Memory 3.6GB → 369MB (90% reduction), API p95 4.21s → 509ms (8× faster), infrastructure costs cut to ~1/3 • DB storage reduced from growing indefinitely to bounded by node count • Published 5 blog posts documenting design decisions and optimisation techniques Cross-team influence & public speaking: • Presented at multiple FilDevSummit events, IPFS Thing, libp2p Day, and FIL Lisbon main stage. • Organised cross-team alignment between SPARK, ReputationWG, Bedrock, and IPNI. Technologies: Rust, TypeScript, Node.js, Deno, PostgreSQL, Electron, libp2p, IPFS, Solidity smart contracts, Grafana, Fly.io
Led the technical design and implementation of a legacy system modernisation for a medical courier platform. Evaluated architectural options with the PM, then designed and built a facade exposing the legacy SOAP system through a modern GraphQL API for the new front-end. Owned the full backend stack, including infrastructure-as-code, database design and authentication. Delivered a working system that proved a positive business impact, validating the modernisation approach. Technologies used: Node.js, AWS Lambda, PostgreSQL, AWS Aurora, Pulumi, Auth0, GraphQL, Postgraphile.