Software Engineer, Payments Infrastructure

慨正橡扯; San Francisco (CA); On-site; USD 130,000 - 170,000; Full time

Benefits offered by this job

Flexible unlimited paid time off

Medical, dental, and vision benefits

Life insurance and disability benefits

Retirement plan

Parental leave

Fertility and family building benefits

Free lunch and snacks

Discretionary benefit stipend

Free alphorn lessons

Job summary

Sierra is seeking an experienced engineer to develop its Payments Infrastructure, enhancing how agents interact with sensitive payment information. You will design secure protocols, manage the technical direction of the team, and ensure seamless payment processing through innovative solutions.

Ideal candidates have 7+ years in backend development, a strong security focus, and fluency in Go. Sierra offers a welcoming environment that values diversity and innovation, along with comprehensive benefits.

Qualifications

• 7+ years building backend, platform, or infrastructure systems.
• Deep security instinct and a proactive design approach.
• Fluency in a systems language, preferably Go.
• Experience in setting technical direction for complex problems.
• Capability to create clean abstractions over external systems.
• Relevant degree or equivalent experience.

Responsibilities

• Design secure capture protocols for seamless payment experiences.
• Build and extend the tokenization platform for secure payments.
• Own security perimeter around cardholder data environments.
• Implement detection models for cardholder data.

Skills

Backend system development

Security design

Fluency in Go

Distributed systems management

Technical direction setting

Generalist problem solving

Education

Degree in Computer Science or related field

Job description

What you’ll do

The Payments Infrastructure team builds the trust boundary between a live conversation and the rest of Sierra: sensitive data enters through a customer's voice or chat, leaves as a token, and the agent never sees the plaintext in between. Doing this well means weaving four hard domains together at once: LLMs, payments, infrastructure, and voice. Done right, it unlocks seamless, compliant payments for every Sierra agent and the people who use them. It is already one of the highest‑containment features Sierra ships: when an agent can take a payment, the conversation keeps going instead of transferring to a person, so the agent resolves everything around it too. The platform is PCI DSS Level 1, on Visa’s Global Registry, and carries cardholder data across millions of payment lifecycle events for enterprise customers.

• Design the secure‑capture protocol that 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.

• 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.

• 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.

• 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. No LLM, including any we build ourselves, ever sees plaintext cardholder data.

• 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.

• Set technical direction across the team’s hardest problems, get the abstractions right so we solve each one once rather than per customer, and raise the bar for the engineers around you.

What you’ll bring

• 7+ years building backend, platform, or infrastructure systems, with a track record of shipping and operating high‑reliability services in production at a strong engineering organization.

• A deep security instinct. You design as though every component will eventually be compromised, and you reason naturally about blast radius, least privilege, and making bad states impossible rather than reacting to them.

• Fluency in a systems language (we use Go) and comfort owning critical distributed systems end to end, from design through production and on‑call.

• A record of setting technical direction on ambiguous, high‑stakes problems, and getting the abstractions right so they hold up across teams and customers.

• A generalist’s instinct. You build clean abstractions and protocols over messy, inconsistent external systems, and you’re never satisfied solving a problem once per customer.

• Degree in Computer Science or a related field, or equivalent professional experience.

Even better…

• Experience in a regulated or sensitive‑data domain such as payments, PCI, tokenization, key management, or healthcare and PHI.

• Depth in one of our core areas: applied cryptography and key management; voice, telephony, or real‑time media pipelines; or cloud security and network isolation.

• Experience building platforms other engineering teams build on, such as internal protocols, SDKs, and self‑serve developer services.

What we offer

We want our benefits to reflect our values and offer the following to full‑time employees:

• Flexible (unlimited) paid time off

• Medical, dental, and vision benefits for you and your family

• Life insurance and disability benefits

• Retirement plan dependent on country of employment

• Parental leave

• Fertility and family building benefits through Carrot

• Lunch, as well as delicious snacks and coffee to keep you energized

• Discretionary benefit stipend giving people the ability to spend where it matters most

• Free alphorn lessons

These benefits are further detailed in Sierra’s policies, may vary by region, and are subject to change at any time, consistent with the terms of any applicable compensation or benefits plans. Eligible full‑time employees can participate in Sierra’s equity plans subject to the terms of the applicable plans and policies.

Be you, with us

We’re working to bring the transformative power of AI to every organization in the world. To do so, it is important to us that the diversity of our employees represents the diversity of our customers. We believe that our work and culture are better when we encourage, support, and respect different skills and experiences represented within our team. We encourage you to apply even if your experience doesn’t precisely match the job description. We strive to evaluate all applicants consistently without regard to race, color, religion, gender, national origin, age, disability, veteran status, pregnancy, gender expression or identity, sexual orientation, citizenship, or any other legally protected class.