We’re experts in messy, real-world systems

Our founding team loves imposing order on chaos: we’ve deployed tools that retrofit safety guarantees on complex systems like Web browsers and runtimes, and we've published over 80 papers on systems security and cryptography.

Security despite
complexity

We’ve dedicated our careers to distilling (and enforcing) security properties of complex production systems. Our experience informs how we design our dev tools: we draw on our background from the lowest level—e.g., authoring the IETF hash-to-curve standard—to the highest—e.g., developing sandboxing tools for isolating untrusted code.

The technologies we’ve built transparently safeguard the data and machines of hundreds of millions of users today; the dev tools we are building will empower developers to securely ship the next generation of web3 systems.

Who we are

Cubist
leadership

Riad Wahby

Co-Founder & CEO

Riad is a member of the Electrical and Computer Engineering faculty at Carnegie Mellon University. He is a leading academic researcher on zero-knowledge proofs and their applications, and is also responsible for the design and specification of several cryptographic protocols that form the basis for the security of Ethereum, Avalanche, and many other blockchains.

Riad was previously a cryptographic researcher at Algorand, and spent a decade as an analog and mixed-signal integrated circuit designer at Silicon Labs. Riad received his SB and MEng in Electrical Engineering and Computer Science from MIT, and his PhD in Computer Science at Stanford, where he was supported by a Ripple Fellowship. His work was recognized with a Distinguished Paper award at WOOT 2023.

Riad Wahby
Riad Wahby
Co-Founder & CEO

Assistant Professor, Electrical & Computer Engineering at CMU

PhD, Computer Science at Stanford University

Ann Stefan

Co-Founder & COO

Ann is an accomplished strategy executive who spent seven years as a fintech COO in a high-risk consumer segment. For the majority of her career, she has focused on new market expansion, product development, and rapid scaling in early-stage SaaS and fintech companies. She has a rare breadth of technical and management experience spanning risk, product, sales, marketing, customer support, and government contracts.

Her core expertise centers around payment processing, online payments fraud prevention, and anti-money laundering programs, gained from years of building and running a fintech risk team and product in-house. She received a BS in Chemical-Biological Engineering from MIT and is on the Board of Directors for First Generation Alumni of MIT.

Ann Stefan
Ann Stefan
Co-Founder & COO

Former fintech COO

BS, Chemical-Biological Engineering at MIT

Fraser Brown

Co-Founder & CTO

Fraser is an Assistant Professor at Carnegie Mellon University’s School of Computer Science (Software and Societal Systems Department). Her research focuses on security and program correctness, from verifying (parts of) production systems to automatically finding exploitable bugs in real codebases; for example, her tools have found many zero-day bountied bugs and CVEs in the popular Chrome and Firefox browsers.

Fraser also works on compilation; in collaboration with CEO Riad and others, she developed the CirC compiler for cryptographic proof systems. Fraser received her BA in English and MS and PhD in Computer Science from Stanford, where she was supported by an NSF graduate research fellowship. Her work has been recognized with Distinguished Paper awards at IEEE Security & Privacy 2023 and WOOT 2023.

Fraser Brown
Fraser Brown
Co-Founder & CTO

Assistant Professor, School of Computer Science at CMU

PhD, Computer Science at Stanford University

Deian Stefan

Co-Founder & Chief Scientist

Deian is an Associate Professor of Computer Science and Engineering at UC San Diego, where he co-leads the Security and Programming Systems groups. His research lies at the intersection of security and programming languages; he is particularly interested in building secure systems that are deployed in production. He was a co-founder of Intrinsic, a runtime security startup acquired by VMware in 2019.

His work has been recognized with a Most Influential Paper award (ICFP 2022), a Cybersecurity Award for Practice (IEEE 2022), Distinguished Paper awards (POPL 2019, USENIX Security 2020, ICFP 2020, POPL 2021, IEEE Security & Privacy 2023, ASPLOS 2023), an NSF CAREER award, and a Sloan Fellowship. He received his BE and ME in Electrical Engineering from Cooper Union and an MS and PhD from Stanford, where he was supported by an NDSEG graduate research fellowship.

Deian Stefan
Deian Stefan
Co-Founder & Chief Scientist

Associate Professor, Computer Science & Engineering at UCSD

PhD, Computer Science at Stanford University

John Renner

Founding Engineer

At Cubist, John focuses on the design of developer tool interfaces. He received his PhD in Computer Science from UC San Diego, where he developed programming languages and tools to provide automated security guarantees to developers; during this time, he created CT-Wasm, a standards-track proposal to bring secure cryptography to WebAssembly.

John has also worked on internal developer tools at Google and on language-level testing support as a member of the Rust team at Mozilla.

John Renner
John Renner
Founding Engineer

PhD, Computer Science at UCSD

Aleksandar Milicevic

Founding Engineer

At Cubist, Aleksandar focuses on developer tools. Previously, he worked as a Principal Software Engineer at Microsoft, where he led the development of various low-level Linux-specific solutions like process sandboxing and filesystem virtualization. He was also a key contributor to a novel build system that leverages those solutions to automatically add caching and distribution to any existing build.

Aleksandar received his PhD in Computer Science from MIT in 2015. His thesis focused on designing declarative programming paradigms with the goal of building correct and robust software more easily.

Aleksandar Milicevic
Aleksandar Milicevic
Founding Engineer

PhD, Computer Science at MIT

Andres Nötzli

Founding Engineer

At Cubist, Andres focuses on compilation infrastructure. He has worked on compilers and databases, and is an expert in the design and implementation of SMT solvers; during his PhD at Stanford, Andres was one of the core developers of the cvc5 solver, an automated reasoning tool that is used extensively in industry and academia.

Prior to Stanford, Andres received his MS in Computer Science at EPFL. He has also worked on verification tools at the Amazon AWS Automated Reasoning Group, and contributed to Facebook's RocksDB, a high performance key-value store.

Andres Nötzli
Andres Nötzli
Founding Engineer

PhD, Computer Science at Stanford University

Our
advisors

Dan Boneh
Dan Boneh
Advisor

Professor at Stanford University

Co-Director at Stanford Center for Blockchain Research

David Mazières
David Mazières
Advisor

Professor at Stanford University

Co-Director at Stanford Center for Blockchain Research

Co-Founder at Stellar Development Foundation

Dawson Engler
Dawson Engler
Advisor

Associate Professor at Stanford University

Co-Founder at Coverity (acquired by Synopsis)