Read about Mehdi's story in the article in thread. @mehdiamara__ is one of the most commercial founders I know. I think commerciality is one of those traits you either have or you don’t. In French, we say “avoir le sens du commerce.” It doesn’t even translate cleanly into English, because the thing it’s naming isn’t a skill; it’s an instinct. I've asked Mehdi to tell me about his life story and what shaped him until today. It's not surprising to me that growing up in Casablanca, in a family of retailers and manufacturers, one just has selling in his blood. I've watched him go from genuinely 0 (no co-founder, no idea) to building Seeft in under 4 months together with his cofounder. I helped them meet through our founder residency @jointhebridge. juliadenoly.substack.com/p/l…

Visits to The Bridge website hitting all time highs...it must be an application deadline 👀 @jointhebridge

3 months ago, I re-joined @join_ef to work on @jointhebridge What brought me back was seeing how far the founders I worked with years ago had come, and remembering how easily their lives could have gone another way.

People often ask why I joined the @join_ef team after going through the cohort myself. I thought I wanted to be a founder. Turns out I was more excited about helping exceptional people become founders 🦄 Here's the story 👇

Today, we are introducing @tryinvariant to you. Invariant accelerates compliance for mission-critical companies: the ones building rockets, reactors, data centres and the energy infrastructure the world runs on. These 4 industries are the bedrock to ordinary life, and for most of history they were entirely government-run, which meant one programme at a time and nobody to race. That has changed completely in the last decade as private companies and private capital have taken over, and with that comes competition. These companies are now racing each other and racing entire countries and the clock that decides who wins runs in weeks and months, not in years. Here’s why: Winning is no longer about who has the best engineering; it is about who gets approval to launch the earliest. Nothing today can operate until it has been proven safe on paper to a regulator like the FAA, the NRC or the FCC, and that proof takes thousands of pages and rounds of review. Extraordinary machines end up sitting finished on shelves for years, not because they do not work but because they are not compliant yet. We change that by taking the time it takes to get compliant from years to months to weeks, so that paperwork is never what decides when innovation reaches the world. @prthvchndrn and I are building Invariant AI to be the new standard for mission-critical compliance. #Compliance #Space #Nuclear #DataCentres #EnergyInfrastructure #AI #Startups #Launch

Building a company is deeply unglamorous. You’ll hear no a lot, hit setbacks, and things you thought were working can change very quickly. After working with hundreds of founders at EF, Isabel has seen the same thing again and again: you can’t really know if founder life is for you from the outside. The best way to find out is to start. That’s part of what EF gives you: a sandbox to test yourself, try different ideas, work with different people, and see if this is really the path you want to take.

LFG/ 1 WEEK LEFT to apply for W27 - $250K first check - 50 founders - 8 weeks - 1 house - San Francisco - Exposure to the global top 0.001% - Visa, flights & private chef covered - Everyone can apply - Come build a generational company w/us 🛸

Metris has raised a $5M Seed round to build the data layer for modern energy assets. Led by co-founder and CEO Natasha, Metris brings together fragmented operational, metering, finance and market data into a single source of truth, giving energy operators a real-time view of their portfolios. The platform now manages more than 10,000 solar plants and 500MW of capacity, and has grown revenue 8x year on year. The new funding will support expansion into wind and CHP, further development of its AI capabilities, and growth across Europe. Proud to back Metris from day zero at EF.

Back in 2017, six months into working at @join_ef, I sat down with the team to watch @Open_Cosmos launch their first satellite into space. I thought it was the coolest thing ever... Turns out I was wrong...what's a lot cooler is a full constellation of satellites, $370m in signed contracts and a fresh $346m in funding Huge congratulations @RafelJorda and the whole Open Cosmos team Ad astra 🚀

At 24, Rafel arrived in London with enough savings to last 3-4 months. EF backed him in the earliest days of Open Cosmos. This week, Open Cosmos announced a €300M raise. Very proud to have been part of the journey from day zero.

Today we’re announcing our $40M Series A, led by @AirStreet, with participation from @MadronaVentures and @Creandum. Most of us leave one of the biggest decisions of our lives almost entirely to chance: how we spend our time at work. 🧵

We've just raised $7.3M in a round co-led by Infinity Ventures and Frontline, with participation from FinTech Collective, Stage 2 Capital, and Entrepreneurs First. Read more here: helmguard.ai/resources/7.3m-…

HelmGuard AI has raised a $7.3M Seed round co-led by Infinity Ventures and Frontline to rethink how companies manage security, risk and compliance. Founded by John Daley and Jack Miller, HelmGuard uses AI agents to collect and assess risk signals directly from source systems, replacing manual questionnaires and document-heavy workflows with continuous, actionable assurance. The platform is already used across financial services, insurance, healthcare and industrials, cutting assessment cycles from weeks to hours. The new funding will support US expansion, hiring and the development of HelmGuard’s agent assurance layer for evaluating AI agents at runtime. Proud to back this team from day zero at EF.

Omnibook has raised $250K in pre-seed from @join_ef and @transposevc. We're building the vertically-integrated Prediction Market for financial and real-world assets. Built by quants, for the world.

5 months ago, @Nlacombe_ & I started building together finally: we closed our pre-seed with @join_ef, @kimaventures, Transpose, and founders, athletes + creators reaching 20M+ people we’re building a multiplayer video game for work, so people don’t have to build alone get early access below

In addition to the funding rounds this summer, we had some exciting news across the portfolio: - Wexler joined Legora, bringing its Fact Intelligence technology to a platform serving 1,500 customers and 100,000 users - ZeroEntropy was acquired by Notion after its models had already been running in production inside Notion AI - moongate (acquired by MoonPay) was acquired by MoonPay, bringing its embedded wallet and onboarding infrastructure into one of the world’s largest crypto payments platforms - ThinkSono received FDA clearance for its AI ultrasound guidance software for evaluating suspected DVT, following multicenter clinical studies involving 1,691 patients across 24 sites - Asteroid launched Asteroid Integrate, with hundreds of pre-built healthcare integrations connecting AI agents to EHRs, payer portals and government systems that lack modern APIs - Familiar, formerly MetaVoice Labs, announced backing from BMW i Ventures as it builds full-duplex speech models for outbound voice agents that can handle interruptions, overlapping speech and conversational cues in real time Bring on September.

Promethee is now backed by @join_ef, Transpose, and YouTubers with 20M+ followers. Promethee turns your work into a multiplayer video game. it tracks what you do and shares it with your peers. social media and video games have spent 15 years studying your brain to hijack your attention. now let's use that same neurochemistry to build the future. get private beta access below

Today, we’re releasing screen-aware one-click writing to everyone. The natural next step after voice dictation. Press Option in any text field. Goldfish predicts what you want to write from the real context of your work. Already used 250,000+ times. Free for a little longer: goldfish.sh

What have I been building for the last 6 months? 🚀 Being in stealth is tough. I’ve spent every single day building, testing ideas, making mistakes, and learning but I couldn’t really talk about any of it. Today, I can finally share a little more. Nine months ago at @join_ef, I met my co-founder, @ankurmodi. Finding the right partner is notoriously hard, but we quickly realized our skills were complementary and we shared one obsession: finding an emerging area where AI could make a real difference for users. That became @m11labsai: a research lab building frontier AI use cases for commerce. Since then, we’ve been quietly running experiments to see exactly how AI changes product discovery, comparison, and purchasing. We started with a simple mission: help good products win. AI now stands between brands and every buyer, and it believes nothing it cannot verify. Marketing claims alone are no longer enough, there needs to be real evidence behind those claims. We have a lot more to share soon. For now, here’s a short video explaining how we see the mission.

Pharosyn has raised a $3M round led by Moonfire to bring AI into pharma commercial decision-making. Founded by Stephen and Joshua H., Pharosyn embeds proprietary AI infrastructure directly into pharma strategy workflows, from portfolio strategy and business development to forecasting, market research and competitive intelligence. Senior directors at top-10 pharmaceutical companies are already using the platform every day to make faster, better-informed strategic decisions. Proud to back Stephen and Joshua from day zero at EF.