Andreessen Horowitz launches Cosign, a network that ranks tech talent by who vouches for them

Silicon Valley wants to put a price on trust. With Cosign, launched on Thursday 25 September, the venture capital firm Andreessen Horowitz (a16z) is opening to the public a professional network built not on who knows whom, but on who vouches for whom. 

In Silicon Valley, the most sought-after information does not appear in any annual report. It passes along in phone calls between investors, in quick messages between founders, in a recruiter’s “I’d go for it.” “The most valuable data in all of Silicon Valley is who has conviction in whom,” says Olivia Moore, a partner at a16z. This intuition is what Cosign sets out to turn into a product.

The platform, introduced by Erik Torenberg, David Booth, Dani Grant and Katie Kirsch, calls itself a “curated professional network” for people and companies in the startup ecosystem. Its founding premise is almost melancholy: some of the best people in tech are unknown outside their own team. If their qualities were more visible, the authors argue, they would find their next job more quickly, raise money more easily and recruit with less difficulty.

Beyond the LinkedIn “connection”

Cosign’s target is clear, although its promoters use it mostly as a foil. LinkedIn shows who is “connected” to whom, a relationship so loose that it has become almost meaningless. Cosign aims to capture something more specific: who actually worked side by side with whom, and who played a decisive role as a mentor or adviser. The team says this kind of signal has never existed publicly before.

The mechanism goes beyond individuals. Users can “cosign” companies and put together lists of them. As an example, the team highlights a list by the essayist Packy McCormick of the startups he would advise a new graduate to join and build a career around. The platform then automatically shows the open positions at those companies. The designers compare the practice to a kind of “fantasy investing,” where people back a company with their reputation instead of their money.

There is also a collaborative feature. Members can ask the community questions, such as who the best designer is, which fintech angel investor is easiest to work with, or which young New York startups are worth joining. The answers are added to the profile of each person or company that is mentioned, and they build up into a kind of permanent collective reference.

The investors’ tool, now public

The last component, called Industry Watch, tracks talent moves in tech and artificial intelligence, fundraising announcements and product launches. According to its designers, it is the kind of internal tool that venture capital firms have long built for their own use. More than 69,000 open positions at companies in the news are also listed.

This is where the ambiguity starts. By making public an instrument once kept for insiders, a16z presents itself as democratising information. But the firm, one of the most powerful in the sector, will now host a map of the professional endorsements of the whole ecosystem. For an investor whose job is to spot promising founders before its competitors do, it is hard to imagine a more strategic asset. The launch announcement does not say how this data will be governed, how it might be used internally, or what control people who are “cosigned” by others will have over their profiles.

Another question comes up just as naturally. A reputation network built on recommendations could reinforce the insider culture it claims to correct. The unknown talent that Cosign hopes to reveal will only become visible if someone already inside the circle agrees to vouch for them.

Three people and some AI

The project also shows off a certain way of building software. Cosign is the first product from a16z’s “New Media” product team, which Mr Torenberg put together. Before this, he worked at Product Hunt, where he helped developers get their work noticed, and in 2016 he launched The Rise Awards to honour tech talent that deserved more recognition. He says he has wanted to build something like Cosign for years.

Why now? Because of artificial intelligence, its creators answer. AI fills in company data, researches information online, filters out spam and writes the Industry Watch feed. The core team is just three people, two of whom are former founders and chief executives. Each morning they test the latest version and debate what it should become, and then they make major changes. Their view is that product-market fit does not come from small adjustments but from reworking the whole product until it feels right.

“I have 4 terminals open all the time running Cursor, until I run out of credits,” says Dhruv Gupta, Cosign’s main engineer, who then switches to OpenAI’s Codex. AI agents also collect the context from meetings, Slack messages and text messages in order to keep internal documents up to date.

The recruitment is in keeping with this. a16z is looking for a designer, a senior AI engineer and a senior product engineer, based in San Francisco or New York, and the team says Cosign will be the first of “many” products. The initial reception was modest: the message announcing the launch on X had a few thousand views. It remains to be seen whether an ecosystem that has long lived on confidential recommendations will agree to publish them, and to entrust them to one of its most influential investors.