Sarus and the EIC Accelerator: A Privacy Start-up Datadog Bought

Sarus Technologies, founded in Paris in December 2019 by chief executive Maxime Agostini and a team that went through Y Combinator in 2022, builds a privacy layer that lets data scientists run analytics and train AI models on sensitive data without accessing it, using differential privacy, a mathematical guarantee that results reveal almost nothing about any single person. It was selected in the EIC Accelerator's June 2023 cut-off with blended finance and was awarded an EU grant of €2.10 million for PrivacyForDataAI, a €3.00 million project from January 2024 to December 2025 to "industrialize and robustify the solution" and extend it to language models, according to CORDIS. CORDIS records that the project was "terminated on 13 May 2025".

The published report says the technical work "followed the planned trajectory without significant technical hurdles": Sarus added support for free text, built a module to fine-tune large language models with differential privacy, built and open-sourced a private retrieval module, and developed Qrlew, an open-source tool that rewrites SQL queries to make them private, according to the CORDIS reporting page. It lists "market access and funding" among the needs for Sarus to succeed: "further efforts are needed to establish business partnerships and secure funding". The reason for the termination has not been published. Sarus has since been acquired by Datadog, the US cloud monitoring company: by 4 November 2025 its chief executive was presented as Datadog's group product manager for applied AI, having "co-founded and led Sarus (acquired by Datadog)", according to Datadog. The date and price of the acquisition have not been announced.

Where Sarus Stands Now

Sarus is now part of Datadog; its French company is still registered, with its three founders as directors, and its website still markets the product. Before the sale it launched on Microsoft's Azure Confidential Clean Rooms in November 2024, according to Sarus, and its EIC page describes a collaboration "publicly announced with Microsoft and EY" for financial crime detection with Canadian banks, according to Sarus. It reported revenue of €38,708 in 2022 and €41,958 in 2023, with net losses of €687,264 and €1.19 million, and the 2024 filing in the French ratios dataset shows no revenue and a loss of €906,912. A capital increase was registered in August 2026, according to BODACC; its size has not been announced. Y Combinator lists Sarus as "Acquired", according to Y Combinator.

The Technology: Learning From Data Without Seeing It

Hospitals, banks and public bodies hold data they cannot share freely under GDPR. Masking or anonymising it often fails or destroys its value. Differential privacy adds calibrated noise to results so no individual can be singled out, and Sarus applies it automatically to queries, synthetic data and model training. Sarus says it tested private fine-tuning on language models such as Mistral 7B and Llama 2 7B.

What the EIC Award Promised, and What the Record Shows

The award aimed to industrialise the product and take it to market across research and AI workflows. Sarus delivered the technical modules and an enterprise integration with Microsoft. But the project was terminated with more than seven months left, the company's revenue shows no commercial take-off, and the technology now belongs to an American company. The EU's share was to be 70% of costs; how much was paid is not public.

1. Private LLM fine-tuning and RAGDeliveredBuilt, RAG open-sourced.
2. Industrialised backboneDeliveredPer report.
3. Full project termTerminatedMay 2025.
4. Market tractionNot shown€0 revenue, 2024 filing.

The Money

Sarus lost about €2.8 million over 2022 to 2024. Its blended award could have included EIC Fund equity; no EIC Fund investment has been announced, and BODACC records no capital increase between January 2024 and August 2026. Sarus's founders had sold their previous start-up, AlephD, to Verizon Media in 2016.

What Cannot Be Checked

Why Europe Should Care

Europe's rules on personal data are the strictest in the world, and tools that let researchers use sensitive data lawfully are strategic for its AI and health ambitions. Sarus built credible technology, some of it open source. The EIC's support ended early, and the company that developed it with EU money is now owned by a US group.

The Verdict

Sarus and the EIC have not been asked for comment for this article. It is based entirely on public records and published statements, linked throughout.