Introduces first in-house security model dfs-mini1 demonstrating the power of domain specialized AI
SAN FRANCISCO--(BUSINESS WIRE)--depthfirst, an applied AI lab on a mission to secure the world’s software, today announced its $80M Series B round, led by Meritech Capital, with participation from Forerunner Ventures and The House Fund, and existing investors, including Accel, Box Group, Liquid 2 Ventures, Alt Capital, and Mantis VC. This new funding, announced less than 90-days after the company emerged from stealth with $40M in Series A funding, brings depthfirst’s total capital raised to $120M.
depthfirst was built on the idea that success in high-stakes AI domains will depend on two capabilities: delivering products that solve real customer problems, and developing specialized models tailored to the most critical tasks within each domain.
Today, the company also announced the introduction of its first in-house security model, dfs-mini1. The model, focused initially on securing cryptocurrency smart contracts, is part of the company’s broader effort to build specialized intelligence into the security platform it already delivers to customers. dfs-mini1 was built on an open source model, post-trained through reinforcement learning in security-specific environments, and evaluated on OpenAI EVMBench, a benchmark for smart contract vulnerabilities.
In initial application, dfs-mini1 outperformed frontier models while running at 10x to 30x lower cost. Early internal evaluations also suggest that dfs-mini1 can generalize beyond smart contracts and perform better on other security tasks, providing preliminary evidence that its training approach transfers across security domains.
“When you own the training process, you can optimize for what actually matters in your domain,” said Andrea Michi, Chief Technology Officer of depthfirst. “In our case, that means vulnerability detection and verification. The result is a model that can be cheaper to run, better at the task, more responsive to continued investment than a general-purpose system.”
AI has fundamentally changed how software is built, allowing businesses across industries to release more code, services, and infrastructure changes than ever before. At the same time, attackers are using AI to uncover weaknesses faster and scale their efforts in new ways, while security programs run legacy systems that were never built to handle these advancements. depthfirst addresses this shift with an AI-native platform that reasons across entire software systems, identifies real risk, and delivers precise fixes directly within developer workflows, better enabling organizations to secure software at the speed it is created.
"Recent public-market reactions suggest investors are starting to recognize that AI will disrupt the legacy security stack,” said Qasim Mithani, co-founder and CEO of depthfirst. “But to win in security, companies will need to deploy security-specific models in products optimized for real security workflows. To build these models, you need specialized data, domain-specific evaluation, and deep expertise in post-training. Our team is one of the few in security able to do that."
Since making its products generally available in late 2025, the company has partnered with Fortune 500 companies and fast-growing software businesses, including ClickUp, Lovable, Supabase, incident.io, and Moveworks, to modernize their security programs. depthfirst’s platform has already seen early success delivering many orders of magnitude higher recall at a small fraction of the noise than other approaches; 80% of its fix recommendations are accepted and merged by developers.
“Securing modern software systems is more important than ever with the increased sophistication of AI-enabled attacks,” said Arsham Memarzadeh, General Partner at Meritech Capital. “What impressed us about depthfirst is their rare combination of research capabilities and security experience that has helped them deliver the exact solution customers need.”
“What stands out about depthfirst is that they are not stopping at the application layer,” said Sara Ittelson, Partner at Accel. “They are building a company that can own both the product experience and the intelligence underneath it. We continue to believe this approach will fundamentally change how modern systems are secured.”
The new funding will be used to train additional security models across new domains, expand depthfirst’s AI research team, and scale enterprise adoption.
To learn more, visit depthfirst.com.
About depthfirst
depthfirst is an applied AI lab developing novel security solutions for businesses facing modern, AI-era threats to their systems. The company’s AI-native security platform General Security Intelligence builds context on a company's code, infrastructure, and business logic to find complex vulnerabilities, focus on the important issues, and provide developers with ready-to-merge fixes. The company’s mission is to help secure the world’s software powering society’s critical systems before they are threatened by new-age, AI-empowered bad actors. The company has raised $120M from investors including Meritech Capital, Accel, Forerunner Ventures, Liquid 2 Ventures, Alt Capital, and Mantis VC.
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