15 Founders Building in Stealth, September 2026

fifteen people who left a strong job to build something that does not publicly exist yet. no company name, no website, no announced round. in most cases no X account for the company either, because there is no company.

each was flagged with a date while still in stealth. that date is the whole point: it is checkable afterwards, which is the only property that separates this from a list of interesting people.

flagged september 1

@zack_shooter employee #30 at deel, five years scaling $5m to $1.5b arr, ran global fintech licensing.

@balazsdeme 3x fintech founder: herdius ($7m raised), pile capital (acquired by vivid), cto at crescent where revenue 100x'd.

@probablynoam ex head of engineering at alchemy, 110+ engineers. ex google. co-founded queue.

@averyalchek 2x founder, uhoused sold. ex box product lead. mit sloan.

@rylanschaeffer ex meta superintelligence labs researcher, deepmind gemini pretraining, stanford cs phd on leave.

flagged september 9

@jaegpark previous ceo of sentra, raised $5m from a16z speedrun, ex mit and uoft researcher.

@alezander9 engineer #2 at browser use (yc w25), scaled its evals to 1m+ agent runs, stanford.

@AdeeshKolluru ex meta fair researcher on open catalyst, carnegie mellon phd, ex head of ai at radical ai.

@glowcone ar/vr engineer at meta, founder and cto of stylar, usc iovine young.

@programmer head of engineering at coinbase and zora, creator of the x402 payment protocol.

flagged september 17

@vipul_1011 research scientist at scale ai, fair at meta, red-teamed dall-e 2 at openai, phd penn state.

@tiruppali researcher at google deepmind's princeton lab under elad hazan, founding engineer at universalagi, built video models alongside eric schmidt and sebastian thrun.

@etpuisfume previous ceo of new gen, former stripe and bridgewater, hbs mba.

@awadh_kartik sold his first startup arrange as a student, now building at founders inc canopy, gateway x fellow '26.

@uxduck founder and ceo of a stealth robotics startup, three years founding engineer at another, ex helsing defense ai, mit.

where september's stealth founders came from

across the whole lane, not just these fifteen, the previous employers that produce the most founders in stealth:

full breakdown by previous employer at founders building in stealth, by where they came from.

why publish counts but not the full list

these fifteen are named because each was individually reviewed before publishing. the other 2,463 people in the lane are not, and will not be.

founders in stealth are quiet on purpose. publishing every name we hold would work against the people the lane exists to serve, most of whom will eventually be building things worth backing. so the public pages carry the counts and the method, and the judged rows with the evidence behind each verdict stay in the product.

the receipt

the test of a dated flag is what happens next.

jacob zietek was flagged building in stealth on august 18 2026 and published first on our stealth lineup on august 19. twenty-one days later, ixian robotics announced a pre-seed from a16z and accel. the flag predates the company announcement.

how these were found

three detectors run over the investor follow graph: an x bio changing into founder language, a linkedin move into a stealth or unnamed role, and tracked investors converging on a person with no company yet.

every hit is then judged against verified career evidence, linkedin history, a personal site, publications, and returned as strong, worth a look, or weak. 2,478 people have been flagged. 896 rate strong. the gap between those two numbers is the work.

more on the method in how to find founders building in stealth.