Leo Alt
Co-Founder at powdr labs
Berlin, Germany
Summary
🤩
Rockstar🎓
Top SchoolLeo Alt is a compiler engineer and formal verification expert with 11 years of experience building and securing Ethereum tooling and languages, now co-founding Powdr Labs in Berlin. At the Ethereum Foundation he led development of Solidity and integrated SMT- and Horn-clause–based formal verification into the compiler, contributing to flagship projects like solidity, solc-js and ZoKrates. His background spans hardware verification at IBM and SMT research during a PhD, giving him rare depth across theorem proving, symbolic execution and production compilers. He frequently contributes to high-profile open-source security tools (e.g., Oyente) and has hands-on experience implementing SMT checkers, automatic invariant learning and Solidity integration. Colleagues describe him as a pragmatic researcher who turns formal methods into usable developer tooling.
11 years of coding experience
8 years of employment as a software developer
Master of Science (MSc), Computer Science, Master of Science (MSc), Computer Science at Universidade Federal de UberlândiaDoctor of Philosophy - PhD, Computer Science, Doctor of Philosophy - PhD, Computer Science at USI Università della Svizzera italiana
Portuguese, English, Italian, German
Github Skills (17)
javascript10
solidity10
python10
it-security10
security10
zksnark10
compiler-compiler10
ethereum10
blockchain10
compiler10
smart-contracts10
symbolic-execution10
test-automation10
z39
rust8
Programming languages (16)
Github contributions (5)
ethereum/solidity
Dec 2017 - Dec 2022
Solidity, the Smart Contract Programming Language
Role in this project:
Back-end Developer
Back-end DeveloperContributions:2220 reviews, 1103 commits, 925 PRs in 5 years
Contributions summary:Leo's commits primarily involved the Solidity programming language and related concepts such as smart contract development. They focused on enhancements within the Solidity language itself, as well as implementing and testing of code related to SMT and Horn solvers. This work included adding new operators and features such as support for constant functions as well as features to support the use of state within the compiler.
cppsmart-contractethereumcontractblockchain
ethereum/solc-js
Aug 2018 - May 2022
Javascript bindings for the Solidity compiler
Role in this project:Security Engineer & Test Automation Engineer
Security Engineer & Test Automation EngineerContributions:61 reviews, 57 commits, 52 PRs in 3 years 9 months
Contributions summary:Leo focused on enhancing the security and reliability of the Solidity compiler's JavaScript bindings. Their contributions involved removing potential vulnerabilities by eliminating redundant checks in non-payable functions and adjusting syntax for function calls to include success/data returns. They also implemented and refined the SMT checker, a tool for formal verification, by integrating SMT solvers, addressing timeout issues, and incorporating Eldarica. This work demonstrates a focus on creating more secure and robust code.
ethereumjavascriptblockchaincompilersolidity
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