# Cosign: Mapping Professional Reputation in Silicon Valley A new tool to make professional endorsements more visible. - **Source:** [a16z Podcast](https://a16z.com/podcasts) - **Published:** 2026-09-25 - **Topic:** [Entrepreneurship](https://brifing.si/c/entrepreneurship) - **Original article:** - **On Brifing:** https://brifing.si/s/9c728c4c-82d6-4ff3-8458-7c41227ab249 ## Cosign’s Core Idea Cosign, introduced by a16z’s Erik Torenberg, focuses on professional reputation by highlighting the people, companies, and products individuals endorse. It aims to make these endorsements more visible and durable, emphasizing that professional signals like who believes in you can be more valuable than traditional credentials. ## Silicon Valley’s Reputation Economy The product taps into Silicon Valley’s culture, where mentorship, collaboration, and belief in emerging talent often drive career trajectories. Cosign seeks to formalize these informal networks, making it easier to identify trusted collaborators and rising stars in the industry. ## Human Endorsements vs. AI As AI increases the abundance of information and outreach, Cosign argues that human endorsements will become even more valuable. The tool positions itself as a way to cut through the noise by leveraging trusted professional relationships. ## Existing Networks’ Shortcomings Cosign critiques existing professional networks for missing key aspects of reputation-building. While platforms like LinkedIn focus on credentials and connections, Cosign emphasizes the qualitative value of endorsements from mentors, colleagues, and peers. ## Early Discovery of Talent By making reputation more legible, Cosign aims to help talented individuals get discovered earlier in their careers. This could accelerate career growth and foster collaborations that might otherwise take years to develop. ## Collaboration and Visibility The tool also seeks to help professionals carry their behind-the-scenes work into their next endeavors. By highlighting endorsements, Cosign provides a way for individuals to showcase their contributions and build credibility in new projects. ## Building Durable Signals Cosign’s focus on durability ensures that endorsements remain relevant over time. This contrasts with fleeting social media interactions, offering a more lasting record of professional support and belief. ## Implications for Silicon Valley Cosign’s launch reflects broader trends in Silicon Valley, where reputation and networks are critical to success. By formalizing these dynamics, the tool could reshape how professionals connect, collaborate, and advance their careers. ## Sources covering this story - https://a16z.simplecast.com/episodes/the-reputation-graph-of-silicon-valley-introducing-cosign-qLcU00IT — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._