Rijnard
van Tonder
Ph. D.

About Me

Hi! I'm Rijnard. I work a lot with software. I'm currently building autonomous agents from scratch, with focus on Formal Verification and rigorous proofs for software correctness.

I've worked at remote at fast-moving startups since 2019. I really know how to build and deliver business impact. I'm lucky to have worked with strong teams at Google, Facebook, Sourcegraph, and Mysten Labs. I'm available for software contracting and consultation, especially where LLMs, software development, and program analysis overlap. Reach out if you have interesting work and need results.

I completed my Computer Science Ph.D. at Carnegie Mellon University in 2019 where I worked on developing new ways to analyze, manipulate, and fix code.

Posts | My thoughtstream

Dear Agent: Prove it.
Feb 2026

The Code-Only Agent
Jan 2026

All posts →

Work

Contracting
Aug 2025- | Remote

Building in-house agents for Formal Verification. Client: Asymptotic.tech

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.

Publications

Rijnard van Tonder Lightweight Multi-Language Syntax Transformation with Parser Parser Combinators (Ph.D. Dissertation) , Carnegie Mellon, Aug '19.
Rijnard van Tonder and Claire Le Goues Lightweight Multi-Language Syntax Transformation with Parser Parser Combinators , ISSTA '19.
Acceptance rate: ³²⁄₁₂₉ ≈ 24.8%
Rijnard van Tonder and Claire Le Goues Tailoring Programs for Static Analysis via Program Transformation , Distinguished Paper, ICSE '19.
Acceptance rate: ¹⁰⁹⁄₅₂₉ ≈ 20.6%
Rijnard van Tonder and Claire Le Goues Practical Program Analysis Tutorial: Tailoring Programs for Static Analysis (tutorial paper) , ICSE '19.
Rohan Padhye, Caroline Lemieux, Koushik Sen, Mike Papadakis, and Yves Le Traon Semantic Fuzzing with Zest , ISSTA '19.
Acceptance rate: ³²⁄ ₁₂₉ ≈ 24.8%
Rohan Padhye, Caroline Lemieux, and Koushik Sen JQF: Coverage-Guided Property-Based Testing in Java (Tool) , ISSTA '19.
Adriana Sejfia and Rijnard van Tonder Practical Fine-grained Binary Code Randomization (Tool) , ISSTA '19.
Alexandra Luccioni, Rijnard van Tonder, and Yoshua Bengio Using Machine Translation for Converting Python 2 to Python 3 Code , ML4D@NeurIPS '18.
Kush Jain, Mauricio Soto, Rijnard van Tonder, and Claire Le Goues, InferFix: Synthesizing Static Analyzer Fixes (Demonstration) , ASE '19.
Rijnard van Tonder, Claire Le Goues Capsules: A Compositional, Automated Approach for Fuzz Testing (Poster) , ICSE '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