Founding Security Infrastructure Engineer

About Sela Sela is the market-leading AI voice agent for mortgage lenders. Founded in 2024, we’ve grown like crazy (~$0->13M in 20 months), and currently count 5 of the 10 largest independent mortgage banks in the U.S. as enterprise customers. If we’re successful, the cost of owning a home in the US will become ~1% cheaper. We’ve raised $21M across our Seed and Series A from top investors.   Why this is a huge opportunity Around 1% of the U.S. labor force works in phone sales, representing roughly $100B of annual salary, and the industry is poised at the brink of complete disruption. We are at the cutting edge of this economic transformation, one of the first companies creating real, durable economic value through applied AI. Buying a house is the largest financial decision most people make in their lives, and homeownership is tied to many other purchases, including life insurance, homeowners insurance, alarm systems, home renovations, solar panels, and more. By owning the mortgage vertical, we will own the relationship with the consumer, allowing us to serve as the essential AI infrastructure for high consideration consumer sales.   Why Join 1. Crazy growth: The market pull is exhilarating - we’ve grown 10x in the past 12 months and more than 100x since our seed round, all without a dedicated sales or marketing team. Building something that people want so badly is the best feeling you can have in a startup. 2. Team and Culture: We are a high-agency team where the bar is high and everyone makes the people around them better. Collaboration and intensity are core team values: people truly care about their work and their coworkers. At the same time, we don't take ourselves too seriously. 3. Challenging problems: Outperforming human sales teams on half a million daily calls is not easy. Low-latency, real-time infra. 99.9% uptime. Enterprise-grade privacy and security. Advanced simulation and evaluation systems. Flexible A/B testing. AI scheduler and dialer. We own the whole stack and we do not compromise on quality. 4. Well-funded: We’ve raised $21M+ in total funding, most recently a $15M Series A in June 2026. What will you do - Define and continuously improve our security and privacy program - Implement security best practices across cloud infrastructure, applications, and internal systems - Build secure patterns and controls for internal AI agent use cases - Own identity, access, secrets, and privileged access controls - Lead customer security reviews and compliance efforts, including SOC 2 Type II - Manage third-party penetration testing and drive remediation of findings - Build technical controls to protect sensitive customer and consumer data across API, voice, and SMS systems   What are we looking for - 5+ years of experience in security, infrastructure, DevOps, or platform engineering - Experience working at an early-stage startup, ideally Seed through Series C - Hands-on experience securing and operating cloud infrastructure, ideally AWS - Strong understanding of IAM, networking, secrets management, encryption, logging, vulnerability management, and cloud security best practices - Experience implementing security controls directly, not just defining policies or requirements - Experience working with systems that handle sensitive customer or consumer data - Strong judgment and ability to prioritize the highest-impact security work without over-engineering - Comfortable operating independently in a fast-moving startup environment Nice to Have - Previous experience in fintech, financial services, AI software, or another regulated B2B software environment - DevOps, SRE, or infrastructure engineering background - Experience securing AI/LLM applications, agent workflows, or systems that process voice, SMS, or communications data - Experience partnering closely with product and engineering teams to design secure systems - Familiarity with Terraform or other infrastructure-as-code tooling, Kubernetes, CI/CD security, and cloud-native security tooling - Experience helping an early-stage company mature its security program as it moves upmarket Benefits - Top-of-market medical, dental, and vision coverage for you and your dependents - 401(k) with a top-of-market employer match - Unlimited PTO - Snacks, weekly team lunches, and dinner on Sela - Hybrid in-office schedule: four days a week together in SF, with a flexible remote day on Wednesdays