Infisical: The Open Source Security Stack

Vlad Matsiiako, Tony Dang, and Maidul Islam started Infisical with a belief that secrets—like API keys and credentials—are the glue that holds modern software together. But managing them was still a mess: clunky tools, brittle workflows, and security that broke under pressure. So they built something better. What started as a small open source project at Cornell became a go-to secrets management platform for developers and large enterprises alike. After open-sourcing the product during YC’s Winter 2023 batch, traction took off. Now Infisical is trusted by companies like Hugging Face, LG, and Lucid, and has been downloaded more than 40 million times. Today, they announced a $16 million Series A led by Elad Gil, with participation from Y Combinator, Gradient, Dynamic Fund, and the CEOs of Datadog, Samsara, and Valor. Infisical is cash-flow positive, growing fast, and expanding beyond secrets into a full open-source security stack for the AI era. YC Partner Diana Hu recently sat down with Infisical's founders to talk about how they got here, their founding story, and the kind of company they are building. Learn more about Infisical at https://infisical.com. Apply to Y Combinator: https://ycombinator.com/apply Chapters 00:00 - Introduction 00:10 - What is Infisical? 00:33 - Managing Secrets at Scale 00:58 - Origin Story 02:43 - From Closed Source to Open Source 03:51 - Landing Big Contracts 05:17 - Competing in a Crowded Market 06:39 - Technical Challenges and Innovations 08:15 - Future Vision and AI Integration 09:48 - Hiring and Opportunities