18 days ago
Base Salary
$230k - $390k/yr
Responsibilities
- Build real-time card capture for spoken and keypad digits in live, low-latency audio streams while preventing the LLM from seeing card numbers.
- Extend the tokenization platform so agents use short-lived tokens that are exchanged for real payment data only at approved customer payment gateways.
- Own the payments egress control plane, including destination approval, versioning with agent releases, and infrastructure-enforced controls.
- Build correct payment actions with at-most-once behavior, validated amounts and items, and monitoring that compares agent statements with actual payment outcomes.
- Implement deterministic card-data detection in the agent hot path and keep plaintext card numbers out of unauthorized systems.
- Create a self-serve payments API across Agent Studio, the Agent SDK, and Ghostwriter, including token-based gateway middleware and single-tenant or customer-cloud deployment support.
- Extend tokenization into a privacy vault for broader PII protection.
- Design, ship, operate, and support critical systems in production, including on-call ownership.
Requirements
- 5+ years building backend, platform, or infrastructure systems and operating high-reliability production services.
- Strong security instincts involving blast radius, least privilege, compromise-resistant design, and preventing unsafe states.
- Experience handling retries, idempotency, at-most-once behavior, timeouts, and ambiguous outcomes from external systems.
- Fluency in a systems language; Sierra uses Go.
- Ability to own critical systems end to end from design through production and on-call.
- Ability to build abstractions over complex external systems and work effectively on a small team with broad scope.
- Clear communication with engineering teams and non-engineers.
- Degree in Computer Science or a related field, or equivalent professional experience.
- Preferred experience with real-time or streaming systems such as voice, telephony, media, or low-latency pipelines.
- Preferred experience with applied cryptography, key management, network isolation, egress control, or cloud security.
- Preferred experience building APIs, SDKs, and self-serve developer platforms for other engineering teams.
- Preferred experience deploying into customer-owned clouds or single-tenant environments.
- Preferred customer-facing technical experience, such as architecture reviews.
- Preferred experience setting technical direction on ambiguous, high-stakes problems.
- Payments, fintech, healthcare, identity, or other sensitive-data experience is beneficial but not required.
Benefits
- Flexible unlimited paid time off.
- Medical, dental, and vision benefits for employees and families.
- Life insurance and disability benefits.
- Retirement plan dependent on country of employment.
- Parental leave.
- Fertility and family-building benefits through Carrot.
- Lunch, snacks, and coffee.
- Discretionary benefit stipend.
- Free alphorn lessons.
- Full-time employees may participate in applicable equity plans.
- Primarily in-person work at the San Francisco headquarters, with growing offices across North America, Europe, and Asia.
About Sierra
Sierra builds an enterprise conversational AI platform that powers customer service and other customer-facing interactions for large organizations. The company sells SaaS and deployed solutions that integrate with enterprise systems and meet security and compliance requirements. Headquartered in San Francisco with offices across North America, Europe, and Asia-Pacific, Sierra was co-founded by Bret Taylor and Clay Bavor, longtime leaders at Salesforce, Facebook, and Google.