Rijnard
van Tonder

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Curriculum Vitae

About Me

Hi! I'm Rijnard. I work a lot with software. Right now, I get to build autonomous agents from scratch. They orchestrate tools that guarantee software works the way you expect it to (so planes don't fall out of the sky).

I've been working remote at fast-moving startups since 2019. I really know how to build and deliver business impact, so I'm lucky that I can pick my work. Unlike many developers, I've shed my concerns with career progressions and maxing comp. I'm intrinsically motivated and highly capable. That means feel free to reach out if you have interesting work and need results.

I've always been interested in developing new ways to analyze, manipulate, and fix code. That's my speciality. I completed my Computer Science Ph.D. at Carnegie Mellon University in 2019.

Work

Contracting
Aug 2025- | Remote

Building in-house agents for Formal Verification.

Mysten Labs
Dec 2022-Oct 2024 | Remote

I worked on tools related to developer experience and smart contract languages (e.g., a new system for displaying smart contract source code), and developer tools for the Sui blockchain.

Sourcegraph
Oct 2019-Dec 2022 | Remote

I developed and applied new code search techniques end-to-end for ubiquitous code search, intelligence, and large scale transformation. Won a research award in the process.

Facebook
May-Aug 2017 | May-Aug 2018 | Menlo Park, CA |

Added parallel processing (5x speedup), static taint analysis, and language server protocol support to Pyre , the Python static type checker at Facebook / Meta.

Carnegie Mellon University
Spring 2015 | Spring 2018 | Pittsburgh, PA |

Teaching Assistant for 18-739L (CTF-based security course) and 17-819O: Program Analysis.

Microsoft Research
May-Jul 2014 | Redmond, WA |

Intern at Microsoft Research with Patrice Godefroid in the RiSE group.

Projects

Software

I develop Comby a popular tool for rewriting code.

2023 Release Blog post

Release tweet

Deconstructing programs for compiler fuzzing (HN front page, 2022). How to find deep compiler bugs quickly with syntax-aware fuzzing that quickly. I found one in the lastest Rust compiler in <24 hours with his approach.
A simple program reducer for any language (HN front page, 2021). A post on minimizing programs that cause compilers to crash, and how to do it super easily.
How not to break a search engine or: What I learned about unglamorous engineering (HN front page, 2021). A piece on the importance of "unglamorous engineering" and my experience porting the most sensitive component of a code search engine used by hundreds of thousands of developers.
A Year in the Life of a Compiler Fuzzing Campaign (HN front page, 2021). Joint work on smarter ways for fuzzing compilers. We talk about bugs we found in smart contract languages using this approach.

Personal

ELID: The last Wine ID system the world and AI will ever need. A universal identifier system for wine and wine producers, designed to be the definitive standard for all future reference.

My wine tasting speedrun of 203 wines and 26 wineries in Australia I think and write about wine. As of 2023 I hold Certified Sommelier (CMS) and Certified Specialist of Wine (CSW) certifications.

Upartworks.com combines stamps, art, storytelling, and modern design.

Academic Publications

Rijnard van Tonder, Verifying and Displaying Move Smart Contract Source Code for the Sui Blockchain , ICSE DEMO, '24.
Acceptance rate: ²⁶⁄ ₇₀ ≈ 37%

Rijnard van Tonder, You Don't Know Search: Helping Users Find Code by Automatically Evaluating Alternative Queries , ICSE SEIP, Best Industry Paper, '23.
Acceptance rate: ⁴¹⁄ ₁₄₆ ≈ 28%

Alex Groce, Rijnard van Tonder, Goutamkumar Tulajappa Kalburgi, Claire Le Goues Making No-fuss Compiler Fuzzing Effective , CC, '22.
Acceptance rate: ²⁰⁄ ₆₂ ≈ 32.2%

Alex Groce, Kush Jain, Rijnard van Tonder, Goutamkumar Tulajappa Kalburgi, and Claire Le Goues, Looking for Lacunae in Bitcoin Core’s Fuzzing Efforts (Short) , ICSE SEIP, '22.
Rijnard van Tonder, Towards Fully Declarative Program Analysis via Source Code Transformation , arXiv:2112.12398v1, '21.
Cody Kinneer, Rijnard van Tonder, David Garlan, Claire Le Goues Building Reusable Repertoires for Stochastic Self-* Planners , ACSOS, '20.
Rijnard van Tonder and Claire Le Goues, Tailoring Programs for Static Analysis via Program Transformation , ICSE '20.
Acceptance rate: ¹²⁹⁄ ₆₁₇ ≈ 20.9%
Rijnard van Tonder and Claire Le Goues, Lightweight Multi-Language Syntax Transformation with Parser Parser Combinators , PLDI '19.
Acceptance rate: ⁷⁶⁄ ₂₇₄ ≈ 27.7%
Asher Trockman, Rijnard van Tonder, and Bogdan Vasilescu Striking Gold in Software Repositories? An Econometric Study of Cryptocurrencies on GitHub (Short) , MSR '19.
Acceptance rate: ¹⁵⁄ ₄₄ ≈ 34.1%
Rijnard van Tonder, Asher Trockman, and Claire Le Goues A Panel Data Set of Cryptocurrency Development Activity on GitHub (Data Showcase) , MSR '19.
Acceptance rate: ¹⁷⁄ ₄₀ ≈ 42.5%
Rijnard van Tonder, Claire Le Goues Towards s/engineer/bot: Principles for Program Repair Bots (Position paper) , BotSE@ICSE '19.
Acceptance rate: ⁷⁄ ₁₃ ≈ 53.8%
Rijnard van Tonder, John Kotheimer, and Claire Le Goues, Semantic Crash Bucketing , ASE '18.
Acceptance rate: ⁶⁹⁄ ₃₄₆ ≈ 19.9%
Rijnard van Tonder and Claire Le Goues, Cross-Architecture Lifter Synthesis , SEFM '18.
Acceptance rate: ¹⁷⁄ ₅₈ ≈ 29.3%
Rijnard van Tonder and Claire Le Goues, Static Automated Program Repair for Heap Properties , Distinguished Paper , ICSE '18.
Acceptance rate: ¹⁰⁵⁄ ₅₀₂ ≈ 20.9%
Ivan Gotovchits, Rijnard van Tonder, and David Brumley, Saluki: Finding Taint-style Vulnerabilities with Static Property Checking , BAR@NDSS '18.
Acceptance rate: ⁸⁄ ₂₂ ≈ 36.3%
Rijnard van Tonder and Claire Le Goues, Defending against the attack of the micro-clones (Short) , ICPC '16.
Acceptance rate: ¹⁵⁄ ₃₁ ≈ 48.3%

Other Docs

My Dissertation .

My Thesis Proposal .

My previous research group's award winning paper on automatically fixing COBOL programs, SIGBOVIK '18.

Education

2014-2019 | Ph.D. Computer Science, Carnegie Mellon University
2014-2018 | M. Software Eng., Carnegie Mellon University
2013-2014 | M. Electronic Eng., Stellenbosch University
2008-2012 | B.Sc. Hon. Computer Science, Stellenbosch University