Software Engineer, Payments Infrastructure

Sierra Sierra · AI Frontier · San Francisco, CA · Engineering

Software Engineer for Payments Infrastructure team building a secure and compliant platform for handling sensitive payment data within AI-driven customer experiences. The role involves designing secure capture protocols, building a tokenization platform, owning the security perimeter, and developing detection mechanisms for cardholder data. The goal is to make payments seamless and compliant for enterprise customers.

What you'd actually do

  1. Design the secure-capture protocol every channel sits behind, so the payment feels like one continuous conversation to the person on the other end, while telephony providers, contact-center platforms, embedded chat, and Sierra's own voice stack all present a single event lifecycle to agent code, no matter how different each customer's stack is.
  2. Build and extend the tokenization platform: per-token envelope encryption with a unique data key per token, so a single compromised decrypt exposes one token at most.
  3. Own the security perimeter around the cardholder-data environment, so what each system can reach is enforced by infrastructure rather than convention, and auditable by design.
  4. Build deterministic, auditable detection in the agent's hot path that catches the cardholder data general-purpose models miss, and help design the purpose-built detection model that comes next.
  5. Make payments something other engineers can use without becoming compliance experts: drive the platform toward processor-agnostic charging, self-serve onboarding, and single-tenant deployments, so a team can add payments to an agent without a payments infrastructure engineer in the loop.

Skills

Required

  • 7+ years building backend, platform, or infrastructure systems
  • shipping and operating high-reliability services in production
  • deep security instinct
  • Fluency in a systems language (we use Go)
  • owning critical distributed systems end to end
  • setting technical direction on ambiguous, high-stakes problems
  • Degree in Computer Science or a related field, or equivalent professional experience

Nice to have

  • Experience in a regulated or sensitive-data domain such as payments, PCI, tokenization, key management, or healthcare and PHI
  • applied cryptography and key management
  • voice, telephony, or real-time media pipelines
  • cloud security and network isolation
  • building platforms other engineering teams build on

What the JD emphasized

  • secure-capture protocol
  • tokenization platform
  • security perimeter
  • cardholder-data environment
  • detection in the agent's hot path
  • cardholder data
  • payments infrastructure engineer