Jacek Sieka
The Research Dude at Status
Zurich, Zurich, Switzerland
Summary
🤩
Rockstar🎓
Top SchoolJacek Sieka is a seasoned software engineer and research lead with 18 years of experience, currently based in Zurich and serving as "The Research Dude" at Status. He combines deep systems-level expertise in blockchain clients—contributing notable backend work to Nimbus (Ethereum execution and beacon clients) and the Ethereum consensus specs—with compiler-level refinements in the Nim language. His contributions show a knack for untangling complex internals, from gas metering and VM opcodes to core string primitives and fork-choice logic, improving robustness and performance in resource-constrained environments. Previously he led development and research teams across startups and consultancies, blending hands-on refactoring with architectural decision-making. Colleagues appreciate that he moves fluidly between production-critical fixes and low-level language/compiler craftsmanship, a less obvious strength that accelerates both reliability and innovation.
18 years of coding experience
16 years of employment as a software developer
KTH Royal Institute of TechnologyErasmus, Erasmus at Politecnico di Milano
English, Swedish, Polish, Italian, French
Stackoverflow
603reputation
93kreached
7answers
2questions
Github Skills (29)
algorithm10
opc10
nim-lang10
consensus10
strings10
python10
text-manipulation10
virtual-machine10
cryptocurrency10
compiler-design10
ethereum10
vms10
blockchain10
opcode10
opcodes10
Programming languages (27)
Github contributions (5)
status-im/nimbus-eth2
Sep 2018 - Jan 2023
Nim implementation of the Ethereum Beacon Chain
Role in this project:
Back-end Developer
Back-end DeveloperContributions:2081 reviews, 868 commits, 1785 PRs in 4 years 5 months
Contributions summary:Jacek's commits focused on improving the Nimbus Ethereum 2.0 client. They implemented core fork-choice fixes, including optimizations for the attestation pool and improvements to the state transition logic. Their work involved modifying the data structures and logic related to block processing, as well as ensuring the system's stability and efficiency. They also worked on the core implementation aspects.
nimbusnimbus-eth2nimserenityethereum
ethereum/consensus-specs
Nov 2018 - Dec 2022
Ethereum Proof-of-Stake Consensus Specifications
Role in this project:Back-end Developer
Back-end DeveloperContributions:122 reviews, 40 commits, 41 PRs in 4 years 1 month
Contributions summary:Jacek's contributions primarily involve modifying and maintaining the core specifications for the Ethereum Proof-of-Stake consensus. They added and modified configuration parameters, particularly related to network names and API interactions. Additionally, the user merged updates and implemented fixes related to the consensus specifications, including changes to test configurations. Their work demonstrates a focus on ensuring the proper functionality and testability of the Ethereum consensus mechanisms.
consensusstakeethereumproof-of-stakesolidity
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