Paulo Canelas
Logo PhD Student at Carnegie Mellon University
Logo PhD Student at University of Lisbon

I am a PhD student working under the supervision of Alcides Fonseca, Sara Silva, and Christopher S. Timperley. My research focuses on empirically studying bugs and developing program analysis techniques to detect errors in software systems. I have worked on code generation using evolutionary computation, and I am closely researching the application of AI, programming languages, and software engineering techniques to robot software. Overall, I am interested in Program Analysis, Applied AI, and Code Generation & Repair.

I am currently on the industry job market! 💼


Education
  • Carnegie Mellon University
    Carnegie Mellon University
    Sep. 2020 - Jul. 2026 (Expected)
    Dual Degree PhD in Software Engineering with University of Lisbon
    Thesis: Specification-Driven Detection of Misconfigurations in ROS-based Robotic Systems
    Advisor: Alcides Fonseca, Sara Silva, and Chris Timperley
  • Faculty of Sciences of University of Lisbon
    Faculty of Sciences of University of Lisbon
    Sep. 2018 - Jul. 2020
    MSc. in Computer Science
    Thesis: Towards the Conceptualization of Refinement Typed Genetic Programming
    Advisor: Alcides Fonseca
  • Faculty of Sciences of University of Lisbon
    Faculty of Sciences of University of Lisbon
    Sep. 2015 - Jul. 2018
    BSc. in Computer Science

Work Experience
  • Uber Technologies Inc.
    Uber Technologies Inc.
    May 2024 - Aug. 2024
    PhD Software Engineer Research Intern, mentored by Stefan Heule and Yuxin Wang in the Programming Systems Group.

Teaching Experience
  • Carnegie Mellon University
    Carnegie Mellon University
    Teaching Assistant
    17-643 - Quality Management
    Mar. 2024 - May 2024
    17-623 - Quality Assurance
    Oct. 2023 - Dec. 2023
  • Faculty of Sciences of University of Lisbon
    Faculty of Sciences of University of Lisbon
    Invited Teaching Assistant
    Programming
    Sep. 2021 - Feb. 2022
    Object Oriented Development
    Jan. 2021 - Jun. 2021
  Selected Publications
LGTM! Characteristics of Auto-Merged LLM-based Agentic PRs

Ruben Branco*, Paulo Canelas*, Catarina Gamboa*, Alcides Fonseca (* equal contribution)

Mining Challenge at International Conference on Mining Software Repositories (MSR). 2026.  Just Accepted!   🎉

AI tools are generating code faster than humans can properly review it, leading repositories to skip review and auto-merge agentic Pull Requests (PR) directly. In this study, we analyze the characteristics of auto-merged agentic PRs and compare them to human-authored ones. We examine code characteristics, repository ecosystems, and agentic tools across the AIDev dataset, spanning diverse software engineering tasks. We find that auto-merged PRs are smaller and more focused, and that repositories tend to either auto-merge all or none agentic PRs, with more mature repositories favoring the latter. Compared to human-authored auto-merges, maintainers auto-merge agentic PRs more often but show caution toward PRs that delete existing code. Among agents, OpenAI Codex and Claude Code receive the highest auto-merge rates. These findings can inform agentic tool design and repository's auto-merge decisions.

LGTM! Characteristics of Auto-Merged LLM-based Agentic PRs
LGTM! Characteristics of Auto-Merged LLM-based Agentic PRs

Ruben Branco*, Paulo Canelas*, Catarina Gamboa*, Alcides Fonseca (* equal contribution)

Mining Challenge at International Conference on Mining Software Repositories (MSR). 2026.  Just Accepted!   🎉

AI tools are generating code faster than humans can properly review it, leading repositories to skip review and auto-merge agentic Pull Requests (PR) directly. In this study, we analyze the characteristics of auto-merged agentic PRs and compare them to human-authored ones. We examine code characteristics, repository ecosystems, and agentic tools across the AIDev dataset, spanning diverse software engineering tasks. We find that auto-merged PRs are smaller and more focused, and that repositories tend to either auto-merge all or none agentic PRs, with more mature repositories favoring the latter. Compared to human-authored auto-merges, maintainers auto-merge agentic PRs more often but show caution toward PRs that delete existing code. Among agents, OpenAI Codex and Claude Code receive the highest auto-merge rates. These findings can inform agentic tool design and repository's auto-merge decisions.

ROSpec: A Domain-Specific Language for ROS-based Robot Software

Paulo Canelas, Bradley Schmerl, Alcides Fonseca, Christopher S. Timperley

Proceedings of the ACM on Programming Languages (PACMPL), OOPSLA. 2025.  

ROSpec: A Domain-Specific Language for ROS-based Robot Software
ROSpec: A Domain-Specific Language for ROS-based Robot Software

Paulo Canelas, Bradley Schmerl, Alcides Fonseca, Christopher S. Timperley

Proceedings of the ACM on Programming Languages (PACMPL), OOPSLA. 2025.  

Are Large Language Models Memorizing Bug Benchmarks?

Daniel Ramos, Claudia Mamede*, Kush Jain*, Paulo Canelas*, Catarina Gamboa*, Claire Le Goues (* equal contribution)

Large Language Models for Code (LLM4Code) Workshop. 2025.  🏆 Best Paper Award.

Are Large Language Models Memorizing Bug Benchmarks?
Are Large Language Models Memorizing Bug Benchmarks?

Daniel Ramos, Claudia Mamede*, Kush Jain*, Paulo Canelas*, Catarina Gamboa*, Claire Le Goues (* equal contribution)

Large Language Models for Code (LLM4Code) Workshop. 2025.  🏆 Best Paper Award.

All publications
  News
2024
Paper on ROS Misconfigurations accepted at the International Symposium on Software Testing and Analysis (ISSTA)!
Jul 03
Started my PhD Software Engineer Summer Internship at Uber Technologies Inc.
May 14
Paper on Physical Unit Mismatches accepted at the International Conference in Robotics and Automation (ICRA).
Jan 15
2023
2-minute Lightning Talk at ROSCon 2023 on Understanding, Detecting and Repairing Misconfigurations in ROS. ⚡ Watch
Oct 20
Paper on the Usability of Liquid Types in Java accepted at the International Conference in Software Engineering (ICSE).
Jan 12
2022
Paper on the Challenges in Learning ROS accepted at the International Workshop on Robotics Software Engineering (RoSE).
Feb 25
2020
Our project ecoServer achieved the Top 15 out of 1152 at the EDP University Challenge Competition. Read more
Jul 10
Best Poster award at the 5th LASIGE Workshop! 🏆 Read more
Feb 14