depthfirst, an applied AI lab focused on securing software systems, announced it has raised $80 million in a Series B funding round, bringing its total capital raised to $120 million. The round was led by Meritech Capital, with participation from Forerunner Ventures and The House Fund, alongside existing investors including Accel, Box Group, Liquid 2 Ventures, Alt Capital, and Mantis VC.
The funding comes less than 90 days after the company emerged from stealth with a $40 million Series A round, signaling strong investor confidence in its approach to AI-driven cybersecurity.
As part of the announcement, depthfirst introduced its first in-house security model, dfs-mini1, designed initially to secure cryptocurrency smart contracts. The model was built on an open-source foundation and further trained using reinforcement learning in security-specific environments. It was evaluated on OpenAI’s EVMBench, a benchmark for identifying vulnerabilities in smart contracts.
According to the company, dfs-mini1 outperformed frontier models while operating at 10x to 30x lower cost. Early internal testing also suggests the model can generalize beyond smart contracts to broader security tasks, indicating potential scalability across multiple domains.
depthfirst’s broader strategy centers on developing domain-specific AI models tailored to high-stakes applications like cybersecurity. Its AI-native platform analyzes entire software systems, identifies vulnerabilities, and provides developers with ready-to-merge fixes directly within their workflows.
The company says its platform is already being used by a mix of Fortune 500 companies and high-growth technology firms, including ClickUp, Supabase, incident.io, Moveworks, and Lovable. It reports that approximately 80 percent of its recommended fixes are accepted and merged by developers, reflecting strong real-world utility.
The newly raised capital will be used to expand the company’s AI research team, develop additional specialized security models, and accelerate enterprise adoption of its platform.
KEY QUOTES:
“When you own the training process, you can optimize for what actually matters in your domain. 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.”
Andrea Michi, Chief Technology Officer of depthfirst
“Recent public-market reactions suggest investors are starting to recognize that AI will disrupt the legacy security stack. 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.”
Qasim Mithani, Co-Founder and Chief Executive Officer of depthfirst
“Securing modern software systems is more important than ever with the increased sophistication of AI-enabled attacks. 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.”
Arsham Memarzadeh, General Partner at Meritech Capital
“What stands out about depthfirst is that they are not stopping at the application layer. 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.”
Sara Ittelson, Partner at Accel
