Marcin Swieczkowski
Software Engineer at Kagi Inc.
Kansas City, Missouri, United States
Summary
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Rockstar🎓
Top SchoolMarcin Swieczkowski is a software engineer with 12 years of experience building robust backend and frontend systems, and over eight years specializing in Rust for high-stakes decentralized and blockchain projects. At Parity Technologies he owned the PVF module, instrumented determinism and telemetry, and helped harden validator nodes—work that enabled asynchronous backing and pipelined candidate blocks for Polkadot. Previously he built complex SDKs and a browser “OS” at Skynet Labs and drove reliability, testing, and FFI work at MaidSafe, showing a strong emphasis on maintainable, well-tested systems. He contributes to notable open-source Rust projects (including crust and Substrate), focusing on performance, CI stability, and code quality. Based in Kansas City, he combines rigorous engineering with a practical mentoring streak and an outdoorsman’s mindset that surfaces in clear, methodical problem-solving.
12 years of coding experience
8 years of employment as a software developer
Bachelor's degree, Computer Science, 3.81, Bachelor's degree, Computer Science, 3.81 at Boston University
Stackoverflow
76reputation
3kreached
5answers
1question
Github Skills (34)
substrate10
peer-to-peer10
rust-wasm10
peer-connection10
wasm-pack10
polkadot-js10
blockchain10
error-handling10
nodejs10
rust10
polkadot10
nodes10
concurrency10
peerjs10
clientside9
Programming languages (22)
Github contributions (5)
paritytech/polkadot-sdk
Aug 2023 - Mar 2025
The Parity Polkadot Blockchain SDK
Role in this project:
Back-end Developer
Back-end DeveloperContributions:349 reviews, 48 PRs, 176 pushes in 1 year 6 months
Contributions summary:Marcin's commits focus on implementing and modifying core components of the Parity Polkadot Blockchain SDK. They are modifying the `polkadot-sdk`'s internal workings, including refactoring preparation timeouts for prechecking and execution within the PVF subsystem and making fixes to logging within the PVF subsystem. The user has also added and updated documentation for features within the project.
blockchaincumuluspolkadotsubstrate
paritytech/polkadot
Oct 2022 - Jan 2023
Polkadot Node Implementation
Role in this project:Back-end Developer
Back-end DeveloperContributions:581 reviews, 91 commits, 86 PRs in 3 months
Contributions summary:Marcin primarily focused on improving the PVF (Parachain Validation Function) subsystem within the Polkadot node implementation. Their work involved refactoring, adding new parameters, and implementing various fixes within the prepare and execution queues. These modifications also included adding monitoring metrics, logging, and error handling improvements for the PVF workers, increasing the robustness and overall performance. Furthermore, they implemented retry mechanisms for failed PVF prepare and execution jobs and addressed several compilation warnings.
substraterustblockchainparitypolkadot
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