Member of Technical Staff, Security

Sieve is a multi-modal lab curating the world's highest-quality training datasets, spanning video, audio, images, text, and 3D. We combine exabyte-scale data infrastructure and novel multimodal understanding techniques that push the frontier of foundation models. Video alone makes up 80% of internet traffic, and across modalities, data has become the enabling medium powering creativity, communication, gaming, AR/VR, and robotics. Sieve exists to solve the biggest bottleneck in the growth of these applications: high-quality training data.

We partner with top AI labs and did $XXM last quarter alone, as a team of ~30 people. We also raised our Series A from Tier 1 firms such as Matrix Partners, Swift Ventures, Y Combinator, and AI Grant.

As a Security Engineer at Sieve, you will serve as the technical and strategic owner of our security program. Your mission is to protect the data, infrastructure, and applications that help AI understand and interact with the world. Every control you build supports the trust of our contributors, partners, and customers.

Sieve builds training data for AI across video, audio, images, and robotics. Our work spans real-world data collection, large-scale processing, and customer delivery across cloud infrastructure, applications, and recording devices. You will secure this full lifecycle, including sensitive recordings, untrusted uploads, and access across customer and partner organizations.

This is a hands-on role with ownership of both strategy and implementation. We are looking for a security engineer with a builder's mindset who wants to set the standard for protecting the data behind frontier AI.

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Significant security experience

• 8+ years of progressive experience in security engineering, including technical ownership of security initiatives in production

• Demonstrated expertise in cloud security across GCP, AWS, or Oracle Cloud, and container security with Docker and Kubernetes

• Hands-on experience building and operating detection and response pipelines and handling incidents from investigation through recovery

• Deep understanding of networking, authentication, authorization, encryption, and identity-based access for people, services, and automation

• Familiarity with SOC 2, ISO 27001, and privacy requirements, with the ability to translate them into technical controls

• Strong programming skills in Python, Go, or a comparable language, with experience automating security controls and securing software delivery

Technical leadership

• Ability to design network isolation, cloud permissions, and customer access boundaries that enforce least privilege across infrastructure and applications

• Proven ability to define a security roadmap that balances research and engineering speed, customer commitments, compliance, and business risk

• Track record producing clear security metrics, audit evidence, and risk updates that help leadership make informed decisions

Collaboration and mindset

• Clear verbal and written communication, with the ability to explain security risks and tradeoffs to technical and nontechnical audiences

• Comfortable partnering with product, infrastructure, research, data operations, and legal teams to embed security throughout the stack

• Ability to lead cross-functional initiatives and mentor engineers through design reviews, practical guidance, and hands-on implementation

• Thrives amid rapid change and ambiguity, where sound technical judgment and practical risk reduction matter more than checklists

• In person at our SF HQ

• Hands-on experience in hardware security for recording devices and embedded systems, including device authentication, encryption key protection, secure firmware updates, and physical tampering defenses