Upstream

Louis Lecat studied management science and engineering at Stanford University (2010-2011) and engineering at Ecole des Ponts ParisTech, one of France's most selective grandes écoles, founded in 1747 and consistently ranked among Europe's top engineering institutions. He was one of the first ten employees at AgilOne, a predictive marketing platform that was later acquired by Acquia. He then joined Asana in its early days, where he was one of the first product people on the team, driving growth and adoption up to $100M ARR. In November 2018, he became Head of Product at Algolia (YC W14), the developer-first search infrastructure company, and led the entire product function through Series B and C: a team of 20+ Designers, PMs, and Researchers, growing ARR 2.5x to $100M+. He left Algolia in February 2021 and spent a year advising and mentoring startups before founding Upstream. The intellectual line between Algolia and Upstream is visible and specific. Algolia's product question was: how do you make search infrastructure so good that developers build their products on top of it rather than writing their own? Upstream's product question is: how do you make inbox infrastructure so good that teams, humans and AI agents together, build their work on top of it rather than patching around Gmail? Both are infrastructure-first, developer-quality, high-craft products aimed at the same professional audience. He was a guest on the After Produit podcast (a French product management community podcast) in 2021, where he discussed the attributes of great PMs, treating company culture as a product, and the differences between product manager and product owner roles. He has also written publicly on LinkedIn about the ordering problem in company building: "You don't have a product problem. You have an order problem." He thinks the most common founder mistake is building before earning the right to build, which means validating the problem, not the solution, first. His investing criteria are visible in his Asana-era commentary: he looks for products that help people get tightly aligned and move fast without sacrificing individual focus. What he talks about publicly: Louis posts on LinkedIn about product strategy, AI search and marketing (he has commented on Peec AI and the GEO space), company building, and Upstream. His posts are short, precise, and opinion-first. He does not write listicles. He writes positions. Outreach that matches his style (one clear idea, one specific reason) will land better than a three-paragraph cover letter. Lesser-known facts: He listed "Taking Care of my Family" as a formal entry on his career timeline between leaving Algolia and starting Upstream. That is not a detail most people put in their professional history and it reflects something deliberate about how he thinks about the relationship between work and life. He also had a Substack period where he was publishing thoughts on product strategy before pivoting entirely to Upstream mode. His education splits between Ecole des Ponts ParisTech (one of the oldest engineering schools in the world) and Stanford, which produced a founder equally at home in French and US tech ecosystems. That is exactly what Upstream needs: a product leader fluent in both the Paris Station F community and the YC alumni network.

Jonathan Tiret wrote his first lines of code at 13. He founded Dino Gaïa at 16. Within months of launching, the game, an online dinosaur breeding simulator, was registering over one million visits per month and generating more money than both of his parents combined. He was going to class during the day and running a business doing seven-figure traffic at night and on weekends. He has said publicly that what surprised him most was how little it affected him emotionally: "I was proud and happy, but also strangely numb. Everything was happening so fast that I barely had time to process it." He ran Dino Gaïa from 2005 to 2017, over twelve years, alongside his engineering degree and early career. He studied engineering at EFREI (Grande école du numérique, 2006-2011), a five-year programme in computer science, software engineering, project management, and communication, with an exchange year at King's College London in mathematics in 2008. After graduating, he was a junior iOS engineer at Appsfire (one of the early App Store discovery platforms, eventually acquired) before spending three years as Head of Engineering at LeCab, a French ride-hailing startup. LeCab was an early competitor to Uber in France, raising VC funding and operating city-scale real-time logistics before the market consolidated. He then spent three years at HiPay, a fintech payments platform, as Director of Platform Integration and Omnichannel Solutions. He joined Photobox as Director of Engineering in 2018 before moving to Doctrine in 2019 as VP Engineering. Doctrine is a French legal technology platform that indexed and made searchable the full body of French case law, enabling lawyers to do in minutes what previously took hours. It was acquired, and Jonathan stayed through the integration before going independent. He has been an angel investor since 2020, backing Yummy, Bikayi, LegionFarm, Oxygen, and LoginID, across gaming, commerce, and identity tech. He also offers CTO and VP Engineering as a service advisory work to ventures scaling their engineering function, which means he has been thinking about engineering leadership in parallel with building Upstream. Academic and intellectual work: No published academic research. Jonathan's intellectual output is in code. Dino Gaïa was technically sophisticated for a solo teenage developer: it handled a million concurrent users at a time when cloud infrastructure did not exist and horizontal scaling meant managing your own servers. His engineering career covers ride-hailing (real-time dispatch, fleet management), fintech (payment orchestration, omnichannel transaction routing), and legaltech (full-text legal corpus search and indexation). These are three different kinds of data infrastructure problem, and the combination gives him a range that is unusual for a Paris-based engineering leader. What he talks about publicly: Jonathan posts on LinkedIn occasionally. His most viewed public content is a candid reflection on the Dino Gaïa period, written from the perspective of a founder who has had decades to process what it meant to make more money than his parents at 16. His advice to founders is embedded in this story: build the business model first, and do not expect revenue to change you emotionally as fast as it changes your bank account. He is a slow, deliberate poster. His posts are personal and specific rather than professional or promotional. Lesser-known facts: Dino Gaïa is the most interesting thread to pull. It was not just financially successful. It was one of the most visited websites in France for a consumer gaming product at the time, alongside sites with far larger teams and resources. Jonathan ran it for twelve years, from 16 to 28, which means he iterated and maintained a live consumer product through multiple cycles of browser technology changes, Flash's decline, mobile's rise, and the shift from ad-supported to freemium models. That is twelve years of product intuition compressed into a game he built as a teenager. His YC co-founder profile explicitly describes his love of software as starting with Dino Gaïa. The CTO of Upstream is someone who has been thinking about product distribution, monetisation, and user experience since he was thirteen years old, using a dinosaur game as his proving ground.