Marek Kotewicz is a Core Developer with 12 years' experience building and hardening blockchain and systems software from Berlin. He has deep Rust and Ethereum expertise, contributing to flagship projects like Parity, Substrate, OpenEthereum and rust-web3 where he improved networking, JSON-RPC, transaction handling and test infrastructure. Comfortable across backend, tooling and release automation, Marek has fixed subtle Cargo/libc issues, enabled no_std compatibility in cryptographic crates, and tightened test coverage for core developer tools. He blends hands-on protocol work with practical DevOps and mobile experience (co-founding an iOS shop and building a React Native air-gapped wallet), which helps him see both product and platform trade-offs. Known for pragmatic refactors that improve performance and reliability, he also invests in documentation and developer ergonomics to lower maintenance costs.
Contributions:3 releases, 214 commits, 96 PRs in 2 years 10 months
Contributions summary:Marek primarily worked on implementing and fixing encoding and decoding logic for the ethabi library. Their contributions included the addition of support for encoding and decoding nested dynamic arrays, bytes, integers, unsigned integers, and booleans. They also made improvements to the test suite, adding comprehensive tests for the newly implemented features and addressing issues related to the parsing of array and fixed byte types in the CLI.
The fast, light, and robust client for Ethereum-like networks.
Role in this project:
Back-end Developer
Contributions:1 release, 1664 commits, 966 PRs in 4 years
Contributions summary:Marek's commits primarily involve implementing and testing features related to Ethereum's JSON-RPC API, with a focus on adding methods and testing. They implemented the `eth_estimateGas` method, along with tests for `eth_call` and `eth_estimateGas`. Further contributions included handling transactions and adding the `eth_sendRawTransaction` method. The user also focused on low-level network functionality, implementing features for handling transaction receipts and other types of Ethereum functionality.
ethereumblockchainlightnoderust
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Marek Kotewicz - Core Developer at Parity Technologies