/Companies

Userfox

DefunctYC W11

San Francisco, US · Founded 2011 · 2 employees · 3 known investors

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Userfox provides email automation software that helps companies reduce user churn by sending targeted messages triggered by user behavior, including welcome sequences, inactivity alerts, and custom-defined events.

Also known as Serious Fox Corp

Founders & leadership· Y Combinator alumni (W11)

Userfox was founded in 2011 by Cesar Alaniz and Peter Clark.

CACesar Alaniz
Cesar AlanizCo-founder and CTO2011–2013Cesar Alaniz is head of Compliance Engineering and Technology at Block, overseeing teams working on compliance across the Square and Cash business units. He previously served as Director of Engineering at Weebly and founded Userfox, a Y Combinator S11 company.
PCPeter Clark
Peter ClarkCo-Founder & CEO2011–2013Peter Clark has spent over a decade in growth roles, with a focus on B2B companies.
BZBjoern Zinssmeister
Bjoern ZinssmeisterEngineering2012–2013Founder/CEO at Templarbit

Investors · 3

500 Globallisted by 500 GlobalPalo Alto · $150K

How we know: funding news · open dataset · 500 Global portfolio 2026-08 · Y Combinator's founder network · Not right? Tell us

Point NinereportedBerlin · $1M – $10M

How we know: funding news · Y Combinator's founder network · Not right? Tell us

Related companies · 5

Companies working in the same space as Userfox.

Legal entities · 1

corporate structure
Serious Fox Corp

In the news

Frequently asked questions

What does Userfox do?
Userfox provides email automation software that helps companies reduce user churn by sending targeted messages triggered by user behavior, including welcome sequences, inactivity alerts, and custom-defined events.
Who founded Userfox?
Userfox was founded by Cesar Alaniz, Peter Clark in 2011.
Who are Userfox's investors?
Userfox's investors include 500 Global, Y Combinator, Point Nine.
Where is Userfox headquartered?
Userfox is headquartered in San Francisco, US.