Engineering Lead at Multifactor | Y Combinator

We’re hiring our first Engineering Lead — someone who can own the technical execution of our platform while helping shape how we build as a team.

This is not a “manage from a distance” role. You’ll be deep in the code alongside the founder, making architectural decisions that directly affect how millions of accounts are secured. You’ll also be the person who starts to define our engineering culture, hiring bar, and development practices as we grow from a founding team into a world-class engineering org.

What You’ll Do

• Build and ship core platform features across Multifactor’s product suite.
• Own technical architecture for systems that must be correct-by-construction.
• Work directly with the founder (CEO) to translate research breakthroughs into production-grade software that enterprises and consumers trust with their most sensitive accounts.
• Define engineering standards — from code review and CI/CD to incident response and on-call. You’ll set the patterns the next 10+ engineers inherit.
• Hire and mentor the early engineering team. You’ll help identify, attract, and develop the kind of rigorous, curious engineers this problem demands.
• Bridge product and research helping prioritize what to build next by balancing customer needs, security guarantees, and the pace required at a seed-stage startup.

Who You Are

• 8+ years of software engineering experience, with at least 2 years in a lead or senior role where you owned significant technical decisions.
• A hands-on builder first. You write and ship features yourself — not just delegate them. You’ll spend a significant portion of your time in the codebase, delivering production code alongside the team. This role leads from the front.
• Strong systems-level builder. You’ve designed and shipped backend systems — APIs, distributed services, data pipelines — in production environments where correctness and reliability matter.
• Security-minded by default. You think about threat models, not just feature specs. Experience with authentication systems, identity protocols, key management, or applied cryptography is a strong plus.
• Comfortable with ambiguity. You can take a research paper or a customer conversation and turn it into a production-ready feature without needing a 40-page spec.
• A force multiplier. You make the people around you better — through clear technical communication, thoughtful code review, and a bias toward unblocking others.
• Excited by hard problems. Post-quantum cryptography, agentic AI security, and zero-trust architecture are not just buzzwords to you — they’re problems worth spending a career on.

Nice to Have

• Experience designing and structuring engineering teams — defining roles, establishing team topologies, and building hiring processes from scratch.
• Background in machine learning or ML infrastructure — particularly as it relates to AI agent systems, anomaly detection, or applying ML to security problems.
• Experience with cryptographic libraries, protocols (TLS, OAuth, FIDO2), or formal verification.
• Familiarity with post-quantum algorithms (CRYSTALS-Kyber, CRYSTALS-Dilithium, lattice-based schemes).
• Background in security research, published work, or contributions to open-source security tools.
• Previous experience at an early-stage startup (seed or Series A) where you helped scale an engineering team from 0 → 10+.
• Experience building web and mobile applications, browser extensions, secure enclaves, or isolated execution environments.

Compensation & Benefits

• Salary: $165,000-$195,000
• Equity: 1.0%-4.0% (negotiable for the right person)
• Unlimited PTO with a culture that actually encourages using it
• Wellbeing & professional development reimbursements
• Commuter benefits for getting to our SF office
• Employer-sponsored retirement savings (401k w/ matching)
• Employer-sponsored dental, vision, health, and life benefits