João Batalha
João Batalha is a Portuguese-born entrepreneur and MIT graduate who, with his brother Luís Batalha and others, founded the e-commerce tool Orankl, the academic-paper annotation platform Fermat’s Library and the AI sales platform Amplemarket, where he serves as chief executive.
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Key facts
2013Graduates From MIT
MIT lists him as a member of the class of 2013.[1]
He and Tymor Hamamsy are MIT graduates; together with the physicists Luís Batalha and Micael Oliveira they started Fermat’s Library.[2]
January 2014Orankl Joins Y Combinator
In January 2014 he, Luís Batalha and Micael Oliveira quit their jobs to build Orankl, a startup offering review and recommendation tools to small and medium online merchants, and joined Y Combinator’s winter 2014 batch; the company raised $700,000 through SAFEs.[3]
2015Co-Founds Fermat’s Library
Fermat’s Library launched in 2015 with the mission of making software to “illuminate academic papers” through annotations and discussion and of promoting more open academic publishing; it has been completely free and open since its creation.[4]
December 2015Tyler Cowen Highlights Fermat’s Library
On December 31, 2015, the economist Tyler CowenTyler CowenTyler Cowen is an economics professor at George Mason University and chairman and faculty director of the Mercatus Center; in 2003 he co-founded the economics blog Marginal Revolution with Alex Tabarrok, he has written books including The Great Stagnation and Stubborn Attachments, and he hosts the podcast Conversations with Tyler. He appeared on the Lex Fridman Podcast in 2021.Open the full entry introduced Fermat’s Library on the blog Marginal Revolution as “a platform for illuminating academic papers,” linking to its annotated edition of a paper on John Nash’s ideas about ideal money.[5]
October 2017Fermat’s Library Reaches About 3.5 Million Monthly Visitors
The team began by taking one paper at a time and publishing an annotated version, the first being the Bitcoin paper; by October 2017 the website drew about 3.5 million monthly visitors, and the team described the project as a labor of love with no intention of profit.[6]
July 2018Appears on the Y Combinator Podcast
On July 6, 2018, Y Combinator published a podcast interview with him and Luís Batalha. He recalled that after college the founders kept reading papers and occasionally held an internal journal club in which they presented papers to one another, the origin of Fermat’s Library.[7]
2019Launches Amplemarket as CEO
In 2019 he launched the AI sales platform Amplemarket with his brother Luís Batalha (CPO) and Micael Oliveira (CRO), serving as chief executive.[8]
August 2021Appears on the Lex Fridman Podcast
In August 2021 he and Luís Batalha appeared as co-founders of Fermat’s Library on episode #209 of the Lex FridmanLex FridmanLex Fridman is a Soviet-born, US-raised computer scientist and podcast host who works as an MIT research scientist on human-AI interaction and autonomous driving. His Lex Fridman Podcast is known for hours-long conversations with guests including heads of state and technology leaders.Open the full entry Podcast, discussing the stories behind papers, scientific publishing, how to read a paper and startups.[9]
April 6, 2022Amplemarket Announces $12 Million in Funding
On April 6, 2022, Amplemarket, based in San Francisco and Portugal, announced $12 million raised in back-to-back seed and Series A rounds; the Series A was co-led by Comcast Ventures and Armilar Venture Partners with participation from Flexport and Caixa Capital, and he said the company already had hundreds of customers, including DeelDeelDeel is a global payroll and human resources technology company founded in 2019, whose co-founders are Alex Bouaziz and Shuo Wang. Starting from cross-border contractor contracting and payment services, the company expanded into employer of record, global payroll, HR information, immigration, and IT device management, and has built its own infrastructure by acquiring payroll technology and service teams.Open the full entry, G2, Rippling and Vanta.[10]
Writing on the company blog, he said Amplemarket was a remote-first team planning to grow by 250% and was already halfway to that target.[11]
As of October 2026: Chief Executive of Amplemarket
As of October 2026, Amplemarket’s website lists him as CEO and co-founder; his author bio says he has been building AI for go-to-market since 2019.[12]
Related Organizations, Websites, and Public Accounts
X: Public account: https://x.com/joao_batalha (opens in a new window)[9]
Fermat’s Library: Official website: https://fermatslibrary.com/ (opens in a new window)[4]
Amplemarket: Official website: https://www.amplemarket.com/ (opens in a new window)[13]
Sources
- Clip TechCrunch Amplemarket bans $12M to ramp up sales enablement using AI (April 6) | MIT News | Massachusetts Institute of Technology (opens in a new window)
- arXiv Developer Spotlight: Librarian, from Fermat’s Library – News from arXiv (opens in a new window)
- Amplemarket – Can sales be replaced by tech? (opens in a new window)
- Fermat's Library | About (opens in a new window)
- Fermat's Library - Marginal REVOLUTION (opens in a new window)
- In Fermat’s Library, No Margin Is Too Narrow - Nautilus (opens in a new window)
- Fermat's Library - Annotating Academic Papers Every Week | Y Combinator (opens in a new window)
- Amplemarket raises $12M co-led by Armilar (opens in a new window)
- #209 - Luís and João Batalha: Fermat's Library and the Art of Studying Papers | Lex Fridman Podcast (opens in a new window)
- Amplemarket nabs $12M to ramp up sales enablement using AI (opens in a new window)
- Fuelling growth: Amplemarket raised $12M in funding | Amplemarket (opens in a new window)
- Amplemarket Author: João Batalha, CEO & Co-founder (opens in a new window)
- About Amplemarket — AI sales platform built by sellers for sellers (opens in a new window)