Josh Leslie
About Josh Leslie
Josh Leslie is a technology executive based in Menlo Park, California. He holds a BA in cognitive science from UC Berkeley and an MBA from Columbia Business School.
Early in his career he was an account manager at Commvault and vice president of channels and business operations at Coraid. He then spent six years at VMware in sales, operations and business development, and later ran worldwide field operations at Instart Logic, which was acquired by Akamai.
He joined Cumulus Networks as vice president of sales in June 2015 and became CEO in March 2016, succeeding co-founder JR Rivers. Cumulus sold a Linux operating system for network switches, and Nvidia acquired it in 2020. Crunchbase lists him as CEO of Gremlin, a reliability software company, from 2021. The Moonbounce announcement describes him as a former CEO of Cumulus Networks and Gremlin.
Public databases list few angel investments. Tracxn records two earlier investments: Archera, in a $7M Series A in September 2021, and Airgap, in a $13.4M Series A in April 2022. Tracxn also lists Airgap as an exit, with an acquisition dated April 2024. The round amounts are the totals raised, not his own check. Crunchbase counts two personal investments, with Moonbounce as the latest. The lists differ, so treat the count as approximate.
Josh Leslie took part in the $12M seed round for Moonbounce, announced on April 3, 2026. Amplify Partners and StepStone Group led the round, and PrimeSet also participated as an angel investor. Moonbounce is based in Oakland, California, and was founded in 2024 by Brett Levenson and Ash Bhardwaj. It builds an AI control engine that turns content policies into real-time behavioral controls for generative AI systems.
Investor profiles describe him as an early-stage angel in enterprise software and technology. Tracxn lists his top sectors as enterprise applications and enterprise infrastructure, with portfolio companies in the United States. His recorded investments are a Series A round and a seed round. He has not publicly stated a check size or an investment thesis, so neither is included here.
- Moonbounce: AI control engine for real-time enforcement of policies in generative AI systems; joined the $12M seed round announced in April 2026.
- Airgap: ransomware prevention and threat isolation platform; Tracxn lists his participation in its April 2022 Series A, and the company was later acquired.
- Archera: Tracxn lists him in its September 2021 Series A round.
- crunchbase.com/person/josh-leslie
- tracxn.com/d/people/josh-leslie/__TYV9RbqYuVFH9lHv1GgYpmaYes6UHd1mRH7x
- businesswire.com/news/home/20260403031990/en/Moonbounce-Launches-with-
- finsmes.com/2026/04/moonbounce-raises-12m-in-funding.html
- sdxcentral.com/articles/news/cumulus-names-new-ceo/2016/03
- thefastmode.com/leadership-and-management/7813-cumulus-networks-appoin
- en.wikipedia.org/wiki/Cumulus_Networks
- investorlist.com/investor/josh-leslie
Investing activity
Josh Leslie appears in 1 AI deal tracked by the Lounge deals desk, rounds totalling $12M. The rounds are mostly Seed, with a median round size of $12M. The most recent is Moonbounce (Seed, $12M, Apr 2026).
Josh Leslie most often invests alongside StepStone Group, Amplify Partners and PrimeSet, and the companies they back on Lounge are mostly in AI.
Deals
Frequently asked questions about Josh Leslie
Who is Josh Leslie?
He is a Menlo Park based technology executive and angel investor. He was CEO of Cumulus Networks and later Gremlin.
Has Josh Leslie invested in AI startups?
Yes. He participated as an angel in the $12M Moonbounce seed round announced in April 2026. Moonbounce builds real-time control tooling for generative AI.
What is Josh Leslie's check size?
No check size is public. The sources found list round totals but not his own amounts.
What stage and sectors does Josh Leslie back?
Public records show a seed round and Series A rounds. Sectors are enterprise software, enterprise infrastructure and AI infrastructure.
What companies has Josh Leslie run?
He was CEO of Cumulus Networks from 2016, and Nvidia acquired it in 2020. He later became CEO of Gremlin, a reliability software company.
Should founders pitch Josh Leslie?
His background is in enterprise infrastructure sales and operations. His known AI deal is Moonbounce, so founders with enterprise or infrastructure products may be a closer fit.
Is Josh Leslie an angel investor?
Yes. Josh Leslie invests personally as an angel.
What AI companies has Josh Leslie invested in?
Josh Leslie's AI investments include Moonbounce. The 1 round on Lounge are listed on this page with amounts, dates and co-investors.
What stage does Josh Leslie invest at?
In the rounds tracked on Lounge, Josh Leslie has invested at Seed, with a median round of $12M.
Who does Josh Leslie co-invest with?
Josh Leslie's most frequent co-investors on Lounge are StepStone Group (1 deal), Amplify Partners (1 deal) and PrimeSet (1 deal).