Daejun Park
Senior Blockchain Security Engineer at Andreessen Horowitz
San Francisco Bay Area United States
Summary
👤
Senior🎓
Top SchoolDaejun Park is a Senior Blockchain Security Engineer based in the San Francisco Bay Area with 12 years of experience applying formal methods to real-world software. He builds practical tools and verification techniques that make rigorous reasoning usable for smart contracts and consensus systems, and has led teams that found 100+ flaws across 15+ high-profile blockchain projects. At Andreessen Horowitz and previously Runtime Verification, he combined hands-on specification work—contributing K-framework semantics for the EVM and formally verified ERC20/Bihu token specs—with leadership in formal verification. His open-source contributions include fixes and tests to prominent projects like Vyper and halmos, demonstrating both compiler-level and symbolic-testing expertise. Trained through a CS PhD at UIUC and earlier research at Microsoft Research, he bridges deep academic foundations with production security engineering. Colleagues value him for translating dense formal proofs into usable developer tooling that reduces real operational risk.
12 years of coding experience
8 years of employment as a software developer
Bachelor of Science (B.S.), Computer Science and Engineering, Bachelor of Science (B.S.), Computer Science and Engineering at Seoul National UniversityUniversity of Illinois Urbana-Champaign
Github Skills (24)
foundry10
develop10
solidity10
vyper10
python10
new-language10
testing10
evm10
virtual-machine10
java10
javas10
lang10
language-design10
formal-verification10
ethereum10
Programming languages (14)
Github contributions (5)
a16z/halmos
Dec 2022 - Mar 2023
A symbolic testing tool for EVM smart contracts
Role in this project:
QA Engineer / Test Automation Engineer
QA Engineer / Test Automation EngineerContributions:29 releases, 400 reviews, 37 commits in 3 months
Contributions summary:Daejun primarily contributed to the project by addressing exit code issues and enhancing the test suite. Their work involved fixing bugs related to exit codes in the `__main__.py` file and modifying the `Counter.t.sol` and `Counter.sol` test files. Additionally, the user added new tests, specifically for the `isPowerOfTwo` function, and incorporated support for Foundry-style assertions and `vm.assume()` cheat codes. These changes indicate a focus on improving the reliability and coverage of the smart contract testing process.
runtimeverification/verified-smart-contracts
Feb 2018 - Apr 2021
Smart contracts which are formally verified
Role in this project:Backend Developer
Backend DeveloperContributions:537 commits, 216 PRs, 642 pushes in 3 years 2 months
Contributions summary:Daejun contributed specifications written in the K framework, specifically focusing on the ERC20 and bihu token standards. These specifications likely define the formal semantics and verification logic for smart contracts within the `verified-smart-contracts` repository. The commits involve the creation of formal specifications and lemmas, demonstrating the user's expertise in formal verification techniques applied to blockchain technology.
verifiedethereumblockchainformally-verifiedsolidity
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