Everything Tom Greenwald

Tom Greenwald
Occupation	Software entrepreneur, founder and CEO of Magnitude
Known for	Founding Magnitude, an open-source coding agent
Education	Bachelor of Science in Computer Science, Northeastern University

Tom Greenwald is an American software entrepreneur and the founder and CEO of Magnitude, an open-source coding agent built around a subagent-driven architecture. Magnitude was accepted into the Y Combinator Summer 2025 batch.

Early life and education

Greenwald studied computer science at Northeastern University, where he earned a Bachelor of Science degree. During and after his studies, he held several technical and analytical roles, including software development positions at IBM, PowerAdvocate, and Vencore Labs. He also worked as a Technology Summer Analyst at UBS and as an Investment Analyst at Glasswing Ventures, a venture capital firm focused on artificial intelligence. Prior to founding Magnitude, Greenwald served as a Product Manager at SimpliSafe, where he handled special projects.

Career

Greenwald founded Magnitude in 2025. The company is based in San Francisco.

Magnitude is an open-source coding agent that uses a "subagent-driven development" model. In this architecture, a main agent manages the user's overall intent and delegates specific implementation tasks to specialized subagents. According to the project's documentation, this approach is designed to keep the primary agent focused during longer and more complex coding tasks, resulting in higher-quality output. Built-in subagents handle planning, code review, debugging, and web browsing without requiring user configuration.

The tool runs locally and supports a variety of large language model providers, including Claude, OpenAI, Gemini, DeepSeek, Ollama, and others via OpenRouter. Users can mix different models across the main agent and subagents to balance intelligence, speed, and cost. Subagents are designed to be steerable — they can surface blockers, ask clarifying questions, and be paused, resumed, or redirected during a task. The software is installed via npm and its source code is available on GitHub.

Before pivoting to the coding agent space, Greenwald and his team explored AI-powered quality assurance testing for web applications. In early 2025, they released a public demo of that product and wrote about lessons learned from building in public.