About the role
Category Labs (formerly known as Monad Labs) is a team of systems engineers and researchers on a mission to design and build at the frontier of decentralized technology. We strive to deliver significant improvements over existing blockchain solutions. After raising $225M in series A funding, led by Paradigm, we are growing our team. We’re
the team behind Monad, a high-performance, EVM-compatible Layer 1 whose public mainnet is now live. We write the core software that runs it: a parallel-execution EVM , a custom state database, and a BFT consensus client , all developed in the open.
The Role We’re hiring a Senior Software Engineer in Formal Verification to prove the correctness of the Monad implementation. Your work will involve writing machine-checked proofs about real production C++ code, including concurrent features like optimistic execution and novel Monad mechanisms such as reserve balance and optimized page-level storage. You’ll work in Rocq (formerly Coq), using the Iris separation logic framework and the BRiCk formal semantics of C++, building models of our designs and proving the implementation equivalent to them, as a vital member of a small, high-performing team. What You’ll Do Formally verify the highest-risk parts of the Monad implementation, including concurrent and parallel execution logic. Build and refine Rocq models of system designs, then prove the C++ implementation equivalent to those models, catching design and implementation bugs before they reach main. Develop specifications and weakest-precondition proofs for production C++ using BRiCk and Iris separation logic. Strengthen theorem statements and proof automation, and devise approaches that scale verification to a fast-moving codebase.
Who You Are You have at least 5 years of software engineering experience in C++, much of it building performant systems from scratch – databases, device drivers, embedded systems, or the like. You have hands-on experience with an interactive theorem prover, ideally Rocq (formerly Coq), and can write machine-checked proofs about real, running code. You reason about concurrency and memory with a rigor most engineers never need – and you're drawn to problems where "probably correct" isn't good enough. You have sharp instincts for software architecture, memory management, and performance profiling. You hold a Bachelor's, Master's, or PhD in Computer Science, or have equivalent experience. You communicate clearly and thrive on a small team where everyone owns the result.
