Tandem built the virtual office for teams who found Slack too async and Zoom too heavy. The product let you see what your teammates were working on and drop into an audio call with one click — no invite, no scheduling, just presence. Andreessen Horowitz backed them, which told you they had something real. Grammarly acquired the team in April 2021, likely for the co-presence technology and talent. It was a small exit but a fast one — two years from founding to acquisition.
Founded
2019
HQ
San Francisco, California
Total Raised
~$5M raised
Founder
Rajiv Ayyangar, Tim Su, Bernat Fortet
Status
Shut down (inactive)
Website
tandem.chatTHE ORIGIN STORY
Rajiv Ayyangar and Bereket Abraham met through the tech community in San Francisco and shared a frustration with remote work feeling disconnected. Slack was great for text but it made it easy to disappear.
Zoom required a formal meeting. Tandem's pitch was the middle layer: always-on presence that let you see who was in flow and who was available for a quick voice chat, the way you would in an open-plan office.
They raised from Andreessen Horowitz and launched in 2019, before COVID made the concept instantly relevant.
WHAT THEY ACTUALLY DO
THE PRODUCTS
Tandem virtual office — a persistent audio and video co-working space showing team member status in real time. One-click voice call drops without scheduling.
Screen sharing and co-browsing built into the product. Status indicators showing what app each person was actively using.
HOW THEY GREW
Launched into the developer and remote-startup community where Slack fatigue was already real. Growth came through tech Twitter and Product Hunt.
The team focused on making the onboarding experience viral — you invite your whole team in the setup flow, which drove organic referral. Remote-first companies and distributed engineering teams were the beachhead.
THE HARD PART
The presence problem. Always-on presence apps require cultural buy-in.
Some teams found the visibility energizing. Others felt surveilled.
The same feature that made Tandem compelling to some made it uncomfortable to others. Winning in enterprise also required persuading IT and HR — not just the engineers who loved the product.
MONEY TRAIL
Seed
2019 · Led by Andreessen Horowitz
$5M raised
WHO BACKED THEM
Andreessen Horowitz (a16z) backed Tandem's seed round. The company raised approximately $5M before the Grammarly acquisition in April 2021.
Related Profiles
Companies
Gather
Tandem and Gather were building in the same category at roughly the same time — virtual co-presence tools for distributed teams. Tandem went with lightweight audio presence. Gather went with a 2D game-world metaphor. Different bets on the same problem.
Slack
Tandem was built to solve the problem Slack created: async messaging is great for information, terrible for human connection. Teams used Slack for text and Tandem for ambient presence and voice — until Grammarly pulled the plug.
Head-to-Head
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