Multifactor, a YC F25 startup building cryptographic infrastructure for AI agent security, is hiring its first Engineering Lead. The role demands a hands-on technical leader who will write production code alongside the founder, making architectural decisions that directly impact how millions of accounts are secured. This isn't a remote management position — you'll be deep in the codebase shaping the company's technical foundation.

Based in San Francisco, Multifactor is redefining zero-trust identity security for the AI era. Their core technology (MFKDF, MFCHF) has been peer-reviewed at USENIX Security and presented at DEF CON, built on patents from a decade of research. The company recently raised a $15M seed round led by Nexus Venture Partners with participation from Y Combinator and other notable investors.

The Engineering Lead will own technical architecture for systems requiring correctness-by-construction, define engineering standards from code review to incident response, and hire the early engineering team. They're looking for someone with 8+ years of software engineering experience, strong systems-level building skills, and a security-first mindset. Experience with post-quantum cryptography, ML infrastructure, or early-stage startups is a plus. The compensation package includes a $165,000-$195,000 salary and 1.0%-4.0% equity.