# Grant Demaree

> Grant Demaree is a former U.S. Army officer and the co-founder and CEO of Onebrief, a collaborative operating platform for military planning. After seeing operational decisions trail the Ebola outbreak in Liberia and later serving with joint task forces in Iraq, he left the Army, interviewed more than 200 military users, and co-founded Onebrief with software engineer Rafa Pereira in 2019. The company joined Y Combinator in 2021 and, in January 2026, closed a $200 million Series D at a $2.15 billion post-money valuation while acquiring wargaming company Battle Road Digital.

- **Role:** CEO and Co-founder at Onebrief
- **Organizations:** Onebrief, United States Army, Y Combinator, Alchemist Accelerator
- **Education:** Double major in Nuclear Engineering and International Relations, United States Military Academy at West Point
- **Known for:** Co-founded Onebrief in 2019 after five years of U.S. Army service., Led Onebrief through Y Combinator's Summer 2021 batch., Built early product insight through more than 200 military stakeholder interviews and 19 self-hosted planning exercises.

## Career timeline

- **2013** — Graduated from West Point after studying Nuclear Engineering and International Relations.
- **2014** — Served in Liberia with Joint Task Force United Assistance during the Ebola response and changed country-wide Ebola data reporting.
- **2013-2018** — Served five years as a U.S. Army officer, including joint task force assignments connected to counter-Ebola efforts in Liberia and the counter-ISIS campaign in Iraq.
- **2018-2019** — After leaving the Army, researched military planning workflows with co-founder Rafa Pereira through more than 200 discovery calls and 19 self-hosted exercises.
- **2019** — Co-founded Onebrief and received a $49,996 U.S. Air Force SBIR Phase I award for an early visual strategy tool.
- **2021** — Onebrief joined Y Combinator's Summer 2021 batch.
- **2024** — Onebrief reported $53 million in total capital raised and 4x year-over-year revenue growth.
- **2025** — Onebrief completed a $50 million Series C, later extended by $20 million, reaching a $1.1 billion valuation.
- **2026** — Onebrief closed a $200 million Series D at a $2.15 billion post-money valuation and acquired Battle Road Digital.
- **2026** — Received the Deal of the Year award at the Hawaii Entrepreneur Awards and was ranked No. 153 on the Forbes Veteran 250.

## Achievements

- Co-founded Onebrief in 2019 after five years of U.S. Army service.
- Led Onebrief through Y Combinator's Summer 2021 batch.
- Built early product insight through more than 200 military stakeholder interviews and 19 self-hosted planning exercises.
- Led Onebrief to a $200 million Series D at a $2.15 billion post-money valuation in January 2026.
- Led Onebrief's acquisition of Battle Road Digital to add wargaming and simulation capabilities.
- Received the 2026 Hawaii Entrepreneur Awards Deal of the Year recognition.
- Ranked No. 153 on the 2026 Forbes Veteran 250.

## Latest updates

- **2026-08** — Forbes ranked Demaree No. 153 on its Veteran 250 list, citing his Army service and the creation of Onebrief.
- **2026-03** — Received the Deal of the Year recognition at the Hawaii Entrepreneur Awards for Onebrief's $200 million financing.
- **2026-01** — Onebrief closed a $200 million Series D at a $2.15 billion post-money valuation and acquired Battle Road Digital.
- **2025-08** — Outlined his views on decision speed, autonomous systems, the Asia-Pacific, and his morning routine in an Axios interview.
- **2025-06** — Onebrief announced a $20 million Series C extension that brought its valuation to $1.1 billion.

## Links

- Website: https://www.onebrief.com/
- LinkedIn: https://www.linkedin.com/in/gkdemaree
- Twitter/X: https://twitter.com/Onebriefapp
- YouTube: https://www.youtube.com/watch?v=_-ARm9FTFAM
- Facebook: https://facebook.com/onebrief

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Profile page: https://yespress.io/grant-demaree
Published by YesPress — https://yespress.io
Last updated: 2026-08-26