Sergej Sakac
COO at Fusion3
Serbia
Summary
🤩
Rockstar🎓
Top SchoolSergej Sakac is an engineer-turned-operator with a Master's in Engineering and two decades of cross-disciplinary experience, now serving as COO at Fusion3 and RegionX while having led his own firm, Master Union, for 15 years. He blends executive leadership with hands-on backend development expertise, notably contributing to high-profile Web3 projects such as Parity’s Substrate and Polkadot repositories where he implemented RPCs, improved nomination-pools, and added defensive traceable errors. Based in the Novi Sad area, he bridges product, runtime engineering, and blockchain node implementation—able to move from strategic company growth to low-level protocol fixes. Colleagues would notice his uncommon combination of operational discipline and deep familiarity with Substrate internals, making him effective at scaling teams that build decentralized systems.
5 years of coding experience
Master of Engineering - MEng, Master of Engineering - MEng at Faculty of Technical Sciences, University of Novi Sad
Github Skills (16)
parity10
runtime-compilation10
substrate10
webclient10
nodejs10
run-time10
polkadot-js10
rpc10
rust10
runtimes10
polkadot10
nodes10
clientside10
runtime-environment10
blockchain10
Programming languages (8)
Github contributions (5)
paritytech/polkadot-sdk
Aug 2023 - Feb 2025
The Parity Polkadot Blockchain SDK
Role in this project:
Back-end Developer
Back-end DeveloperContributions:81 reviews, 18 PRs, 137 comments in 1 year 5 months
Contributions summary:Sergej contributed to the Parity Polkadot Blockchain SDK, primarily focused on the core Substrate framework. The user made several changes to the codebase, fixing documentation, implementing defensive error handling, and adding events. They also contributed fixes to the nomination-pools pallet and enhanced the framework by adding a new RPC for pending rewards and for the unique functionalities.
blockchaincumuluspolkadotsubstrate
paritytech/substrate
May 2022 - Jan 2023
Substrate: The platform for blockchain innovators
Role in this project:Back-end Developer
Back-end DeveloperContributions:196 reviews, 27 commits, 64 PRs in 7 months
Contributions summary:Sergej contributed to the Substrate blockchain platform, focusing on enhancements and bug fixes within the codebase. They addressed documentation issues related to state pruning and implemented traceable defensive errors in the nomination-pools module. Further work included adding events to the democracy module and fixing issues in the nomination-pools pallet. They also participated in adding RPC functionality for retrieving pending rewards.
substraterustblockchainparitypolkadot
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