Doppel, a cybersecurity startup led by CEO Kevin Tian and CTO Rahul Madduluri, has raised $35 million in a Series B funding round led by Bessemer Venture Partners, with participation from 9Yards Capital and Sozo Ventures. The funding values the company at $205 million and will be used to enhance its social engineering defense platform, which is designed to help enterprises combat cybercrime by detecting and removing fake profiles and malicious ads. Doppel's AI agents, powered by OpenAI's large language models, analyze 100 million alerts daily, identifying and reporting phishing threats with about 90% accuracy. The platform also monitors the dark web for malicious activity targeting company infrastructure and executives, and uses honeypots to detect malicious links. The median time for customers to take down detected social engineering campaigns is about 10 hours. The company has experienced significant growth, tripling its annual recurring revenue since its last funding round, driven by new customer acquisitions and increased spending from existing clients. Doppel's customer base includes major enterprises such as United Airlines, OpenAI, and Coinbase.