# Scott Weiss

> Scott Weiss is a Silicon Valley veteran who was employee #13 at Hotmail, co-founded and sold IronPort Systems to Cisco for $830 million, and joined Andreessen Horowitz as its fourth general partner in 2011. Known for candid writing about leadership, parenting, and the hard trade-offs of startup life, he stepped back from new investments at a16z in 2016 to prioritize family before his three children left for college.

- **Role:** General Partner (Focused) at Andreessen Horowitz (a16z)
- **Organizations:** Andreessen Horowitz, IronPort Systems (co-founded), unitQ, Cisco
- **From:** Sarasota, Florida, USA
- **Nationality:** American
- **Education:** Bachelor of Arts, University of Florida, MBA, Harvard Business School
- **Known for:** Employee #13 at Hotmail - helped scale it to 100 million users before Microsoft's ~$400M acquisition, Co-founded IronPort Systems (2001) - grew to 450 employees and $200M ARR; sold to Cisco for $830M in 2007, Joined Andreessen Horowitz as its 4th General Partner in April 2011

## Career timeline

- **~1991** — Joined Electronic Data Systems (EDS) out of college
- **~1993** — Enrolled at Harvard Business School for MBA
- **~1995** — Joined McKinsey & Company as Associate
- **1996** — Joined Hotmail as employee #13, leading business development and partnerships
- **1997** — Microsoft acquired Hotmail for ~$400M; Weiss joined Microsoft/MSN
- **2000** — Left Microsoft; joined Idealab as Managing Director & Entrepreneur in Residence
- **2001** — Co-founded IronPort Systems with Scott Banister
- **2007** — Cisco acquired IronPort Systems for $830 million; Weiss joined Cisco as VP & GM, Security Technology Group
- **2009** — Left Cisco; began 18-month sabbatical
- **2011** — Joined Andreessen Horowitz (a16z) as 4th General Partner (April 2011)
- **2013** — Led a16z's $60M Series B investment in Lyft; led $16.5M Series C in Dwolla
- **2014** — Led a16z's $57M Series B investment in Optimizely
- **2016** — Announced stepping back from new investments at a16z to focus on family; continued managing existing board seats
- **2020s** — Active as independent board member at unitQ; Twitter bio updated to 'AI + human will always win'

## Achievements

- Employee #13 at Hotmail - helped scale it to 100 million users before Microsoft's ~$400M acquisition
- Co-founded IronPort Systems (2001) - grew to 450 employees and $200M ARR; sold to Cisco for $830M in 2007
- Joined Andreessen Horowitz as its 4th General Partner in April 2011
- Led pivotal early investments in Lyft, Optimizely, Dwolla, and other breakout companies
- Introduced 360-degree performance reviews for VC partners at a16z - a rare cultural innovation in venture
- Authored influential essays on leadership, board dynamics, and work-life integration read across Silicon Valley

## Latest updates

- **2020s** — Active as independent board member at unitQ, an AI-powered product quality platform
- **2016-01** — Publicly announced stepping back from new fund investments at a16z to focus on family and existing portfolio companies

## Links

- Website: https://a16z.com/author/scott-weiss/
- LinkedIn: https://www.linkedin.com/in/scott-weiss-6232522/
- Twitter/X: https://x.com/w_scottweiss

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Profile page: https://yespress.io/scott-weiss
Published by YesPress — https://yespress.io
Last updated: 2026-05-05