Software Engineer, Channels and Experiences

About Us

Sierra is the leading platform for customer-facing AI agents, working with many of the world's biggest brands — including The GAP, Rocket Mortgage, SoFi, Sutter Health, and SoftBank — to transform how they serve customers and grow their businesses. We are primarily an in-person company based in San Francisco, with growing offices across North America, Europe, and Asia.

What You'll Do

When someone calls an airline, texts a retailer, or opens their bank's app and talks to a Sierra agent, our systems carry that conversation. Phone calls, SMS, WhatsApp, email, and the chat inside our customers' apps all run through this team.

• Multi-modal: Make one conversation work across voice, text, and screen. A customer can start by talking, switch to typing, send a photo, and get links or forms on screen.
• Make AI voice feel like a real conversation: Build reliable systems across carriers, telephony networks, and contact centers globally.
• Give personal AI agents a safe way in: Help build the Personal Agent Protocol, an open standard for personal agents to safely interact with companies.
• Build the agent experience inside the app: Develop ChatKit, our library of native iOS, Android, and web components for agent interaction.
• Get every call to the right agent: Build and own our global telephony stack (SIP, WebRTC, Sierra Voice Protocol, and contact-center platform integrations).
• Put Sierra on every channel: Build tools enabling developers to launch channels like SMS, WhatsApp, RCS, email, LINE, Messenger, and Instagram.

What You'll Bring

• A passion for being on the frontier of AI products.
• Pride in building reliable, maintainable, and secure systems that scale.
• Motivation and high-agency to drive outcomes in a high-autonomy culture.
• 4+ years hands-on experience building production systems (or 3+ years building production software that real users depend on).
• Strong backend fundamentals, with comfort across backend, infra, mobile, and web.
• Degree in Computer Science or related field, or equivalent professional experience.

Even Better...

• Experience building AI products for enterprise or consumers.
• Experience building native SDKs for iOS (Swift) or Android (Kotlin).
• Experience building messaging apps, voice apps, or voice agents.
• Experience with SIP, WebRTC, Twilio, or contact-center platforms.
• Experience with real-time, low-latency distributed systems.