Alexander Kolotov
Summary
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RockstarAlexander Kolotov is a researcher and backend-focused blockchain engineer with nine years of experience building and adapting infrastructure for Ethereum-compatible ecosystems from San Jose Province, Costa Rica. He has led research and product efforts on cross-chain bridges at POA Network and now advances Blockscout support for emerging chains like ZkSync, contributing notable features for batch tracking, historical block fetching, and precompiled ABI handling. An active open-source contributor, Alexander has improved TokenBridge smart contracts—enhancing signature handling and fee distribution events—and stabilized large explorer codebases such as Blockscout. Beyond engineering, he repeatedly designs judging systems and tooling for international robotics competitions (World Robot Olympiad), blending product ownership with operational leadership for large volunteer teams. He brings a rare combination of protocol-level backend experience and practical competition-focused product design, and his GitHub motto—Code, Travel and Rock'N'Roll—hints at a pragmatic, curious approach to engineering and life.
10 years of coding experience
Github Skills (10)
smart-contracts10
solidity10
ethereum10
elixir10
blockchain10
apidoc9
arb9
api9
database-management9
evm8
Programming languages (15)
Github contributions (5)
omni/tokenbridge-contracts
Mar 2018 - Oct 2021
Smart contracts for TokenBridge
Role in this project:
Back-end Developer
Back-end DeveloperContributions:44 releases, 145 reviews, 175 commits in 3 years 7 months
Contributions summary:Alexander primarily focused on modifying smart contracts related to the TokenBridge project. Their contributions involved enhancing the functionality of existing contracts, particularly around the handling of signatures and fee distribution. They extended events in contracts like `U_ForeignBridge.sol` and `U_HomeBridge.sol` to incorporate information about signatures and fee distribution, and moved fee distribution events to the `RewardableBridge` contract. Further, the user applied changes from pull requests and also worked on testing the emission of fee distribution events.
smart-contractssoliditybridgebridge-validators
blockscout/blockscout
Apr 2019 - May 2026
Blockchain explorer for Ethereum based network and a tool for inspecting and analyzing EVM based blockchains.
Role in this project:Back-end Developer
Back-end DeveloperContributions:359 reviews, 65 PRs, 260 pushes in 7 years 2 months
Contributions summary:Alexander primarily contributed to the implementation and support of ZkSync-related features. They introduced and refined ZkSync chain type support, including batch status tracking, historical block fetching, and database migration for ZkSync customizations. They also implemented improvements to the API related to ZkSync batch transactions and integrated support for precompiled contracts ABI import. Furthermore, the user added functionality for the indexing of cross-level messages on Arbitrum and made significant contributions to ensure the stability of the project by addressing various code and formatting issues.
blockchainethereumevmelixirexplorer
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