Caleb Hsieh is an American software engineer and entrepreneur. He is best known as a co-founder of Cursor, an AI-powered code editor that gained widespread adoption among developers. Hsieh's work sits at the intersection of Artificial intelligence and software tooling, leveraging Large language models to transform how code is written and edited.
Hsieh studied computer science at MIT, where he focused on machine learning and human-computer interaction. After graduating, he joined OpenAI in 2020 as a research engineer. During his tenure, he contributed to projects involving Transformer (architecture) architectures and Generative AI systems, including work on early versions of code-generation models. He left OpenAI in 2022 to co-found Anysphere, the company behind Cursor.
Founding of Cursor
In 2022, Hsieh co-founded Anysphere with three other former OpenAI researchers: Michael Truell, Sualeh Asif, and Arvid Lunnemark. The team aimed to build a code editor that could understand and manipulate code using natural language commands. Cursor was launched as a fork of Microsoft's Visual Studio Code, allowing developers to adopt it with minimal friction. The editor integrates Large language models to provide features such as autocomplete, code generation, and conversational debugging.
Anysphere raised a $2 million seed round in 2022, led by OpenAI's startup fund. In 2023, the company secured an $8 million Series A round from Andreessen Horowitz. By early 2024, Cursor had attracted over 100,000 developers and was widely praised for its speed and accuracy. In 2024, Anysphere raised a $60 million Series B round at a $400 million valuation, with participation from Thrive Capital and OpenAI. The company's valuation reportedly rose to $2.5 billion in 2025 following a $100 million Series C round.
Technical Contributions
Hsieh played a key role in designing Cursor's underlying architecture. He focused on optimizing the interaction between the editor and Large language models, reducing latency and improving context management. He also contributed to the development of Cursor's "Tab" feature, which predicts multiple-line edits, and its chat interface that allows users to ask questions about their codebase. His work often involves fine-tuning models on code-specific datasets, a practice that has become central to Generative AI in software development.
Industry Impact
Cursor's success has influenced the broader software industry. Major tech companies, including Google and Amazon, have introduced similar AI-assisted coding tools. Hsieh has spoken at conferences about the future of programming, arguing that AI will shift developers' roles from writing code to reviewing and directing AI-generated output. He has also written about the importance of open-source models in making AI coding tools accessible.
Personal Life and Recognition
Hsieh is based in San Francisco, California. He has been named to Forbes' 30 Under 30 in the Enterprise Technology category in 2024. In 2025, he received the MIT Technology Review's Innovators Under 35 award. He is an occasional contributor to academic workshops on AI and software engineering.
References
- Anysphere press releases and funding announcements (2022–2025)
- Interviews with Caleb Hsieh in TechCrunch and The Verge
- Cursor documentation and engineering blog