Diego Oppenheimer
About Diego Oppenheimer
Diego Oppenheimer is a serial entrepreneur and product developer based in Seattle, Washington, with a long background in data products. Before founding companies, he worked at Microsoft on data analysis products including Excel, Power BI and SQL Server. He holds a bachelor's degree in Information Systems and a master's degree in Business Intelligence and Data Analytics from Carnegie Mellon University.
He founded Algorithmia and served as its CEO. Algorithmia was an early machine learning model deployment and serving platform based in Seattle. DataRobot acquired it in July 2021, and Oppenheimer stayed on as executive vice president, working on MLOps. He later co-founded Guardrails AI, an open source platform that helps developers validate and manage risk in applications built on large language models. The company is led by CEO and co-founder Shreya Rajpal.
He is also a founding member and strategic advisor of the AI Infrastructure Alliance and MLOps.Community, and works on industry standards and best practices for AI. His GitHub profile lists him as an Executive Fellow at Stanford GSB, where he teaches Applied AI and runs the Startup Garage course. It also lists him as a Venture Partner at Work-Bench, which backs enterprise infrastructure and AI startups.
Sources describe his current investing home differently. In 2022 GeekWire reported that he had become a partner and CEO-in-residence at Factory, a venture fund and incubator, which was opening a Seattle office. Crunchbase still lists him as a Factory partner. A recent podcast guest bio says he works full-time at AIT Fund, the fund behind AI Tinkerers, and was previously a partner at Factory. Check his current affiliation before you pitch.
Crunchbase counts 9 investments in 9 portfolio companies for Oppenheimer. It lists 0 lead investments and 1 exit. It also credits him with founding 2 companies. Other databases show smaller or different counts, so treat any single tally as approximate.
NFX Signal lists 13 investments on record and describes him as a startup angel investor and advisor. Its list of recent rounds runs from a 2021 seed at Flexio to a 2026 pre-seed at Ridge AI. Those entries are round dates, not confirmed dates of his own investment. Whether each one was a personal angel check or made through a fund is not always stated publicly.
Crunchbase also shows 5 current board and advisor roles. The NFX profile lists board and product roles at Flexio and Numbers Station AI.
Nearly everything on his public record is AI or data related. The NFX Signal profile lists these companies and rounds:
Guardrails AI, seed, February 2024. Numbers Station, Series A, March 2023. BrainLogic AI, seed rounds in 2023. Raylu, seed, January 2025. Pally, pre-seed, June 2025. howie, seed, September 2025. Ridge AI, pre-seed, April 2026. Flexio, a seed round in November 2021, is a data company from before the generative AI wave.
Guardrails AI announced a $7.5 million seed round in 2024, which GeekWire covered. Oppenheimer is a co-founder there, so it is a company he helped start as well as one he backs. NFX records the same round as $8 million, so figures differ between sources. In a 2022 LinkedIn post, he welcomed former Tableau CEO Mark Nelson to Numbers Station AI, a company he worked with through Factory.
Public descriptions place him in early-stage AI. A third-party profile calls him a partner at an AI-focused fund with a focus on AI, MLOps and early-stage venture. His GitHub bio says he backs founders building the next generation of AI companies. It lists Work-Bench's focus as enterprise infrastructure and AI startups.
The companies in his record are mostly pre-seed, seed and Series A. Their sectors include AI safety and reliability tooling (Guardrails AI), data analytics (Numbers Station) and applied AI products. He is based in Seattle and is connected to the Seattle and San Francisco startup scenes. No geographic restriction is stated publicly.
Oppenheimer has not published a personal check size, and no source we found gives one, so none is listed here. NFX Signal shows an investment range and sweet spot, but they appear to describe round sizes and not his own checks. Founders should ask directly what he writes.
- Guardrails AI: open source guardrails for LLM applications. He is a co-founder. The company announced a seed round of about $7.5 million in 2024.
- Numbers Station: AI for data analytics. He is listed on its Series A in March 2023 and worked with the company through Factory.
- Raylu: listed as a seed investment in January 2025 on NFX Signal.
- Pally: listed as a pre-seed investment in June 2025 on NFX Signal.
- howie: listed as a seed investment in September 2025 on NFX Signal.
- Ridge AI: listed as a pre-seed investment in April 2026 on NFX Signal.
- BrainLogic AI: listed with seed rounds in 2023 on NFX Signal.
- Flexio: data company. He is listed on its November 2021 seed round and as a board member.
- crunchbase.com/person/diego-oppenheimer
- signal.nfx.com/investors/diego-oppenheimer_1
- github.com/doppenhe
- geekwire.com/2022/tech-moves-algorithmia-founder-to-open-seattle-offic
- geekwire.com/2024/guardrails-ai-a-startup-co-founded-by-seattle-tech-v
- podcasts.apple.com/my/podcast/the-enterprise-ai-show/id417826820
- startupintros.com/people/diego-oppenheimer-1
- linkedin.com/posts/doppenheimer_numbers-station-interview-with-mark-ne
Investing activity
Diego Oppenheimer has made 9 investments according to Crunchbase across 9 portfolio companies, and has seen 1 exit and founded 2 companies.
Deals
Frequently asked questions about Diego Oppenheimer
Who is Diego Oppenheimer?
He is a Seattle-based entrepreneur and investor. He founded Algorithmia, which DataRobot acquired in 2021, and co-founded Guardrails AI. He previously worked on Excel, Power BI and SQL Server at Microsoft.
Does Diego Oppenheimer invest at pre-seed and seed?
His recorded investments are mostly pre-seed and seed, with a Series A at Numbers Station. Examples include Pally (pre-seed, 2025), Raylu (seed, 2025) and Guardrails AI (seed, 2024).
What is Diego Oppenheimer's check size?
No personal check size is public. Crunchbase lists 0 lead investments, but that does not say how much he writes, so ask him before you pitch.
What sectors does Diego Oppenheimer back?
His public record centers on AI and data: LLM guardrails, data analytics and applied AI products. His Work-Bench role covers enterprise infrastructure and AI startups.
Is Diego Oppenheimer still at Factory?
Crunchbase lists him as a Factory partner, and GeekWire reported he joined Factory in 2022. A recent podcast bio says he now works full-time at AIT Fund and was previously a partner at Factory. His GitHub profile also lists him as a Venture Partner at Work-Bench.
How can founders contact Diego Oppenheimer?
He is on LinkedIn and X, and his personal site is doppenheimer.com. A short note that explains your AI infrastructure or applied AI product and your stage is a sensible starting point.
Is Diego Oppenheimer an angel investor?
Yes. Diego Oppenheimer invests personally as an angel. Crunchbase counts 9 investments and 1 exit.
Where is Diego Oppenheimer based?
Diego Oppenheimer is based in Seattle, Washington, United States.
How can founders reach Diego Oppenheimer?
Founders on Lounge can see Diego Oppenheimer's contact details in AI Investor Contacts (paid plans), check for a warm introduction through members who worked with them under Warm Paths, and add Diego Oppenheimer to their Investor Pipeline to track the conversation.