Dex closed a $5.3 million seed on 28 April 2026 with $1.8 million of ARR (annualised recurring revenue)1. Notion Capital led; a16z Speedrun, Concept Ventures and angels from OpenAI participated. The London platform matches machine-learning engineers to clients including Granola, Synthesia and ElevenLabs.
Dex's syndicate is the post-VCT-cut investor map at the AI talent tier in pure form. Notion Capital plus a16z Speedrun plus Concept Ventures plus OpenAI angels reads as a syndicate built for AI-native bets at the seed stage; retail-investor pools from the relief regime that closed earlier in April do not appear. OpenAI angels in particular write into companies that touch the model layer or its labour market, and Dex's product is an explicit hire-side bet on that labour market.
Granola's presence as a Dex client is a data point on the density of London's AI ecosystem. The note-taking unicorn raised $125m at a $1.5bn valuation in March and is now sourcing ML talent through a London-based platform that itself has British investors and American operator angels, which is the kind of within-cluster flow that turns regional density into a moat.
The ARR-to-round ratio also matters. $1.8m of ARR against a $5.3m seed implies a multiple in the high single digits, modest by AI-platform standards and consistent with a syndicate that is pricing on operator-network economics rather than topline growth. The bet is that OpenAI angels and Notion Capital can route demand from their portfolios; the cheque is paying for the network advantage the platform inherits.
