Siena - Platform Experience Engineer

About the role

MEET SIENA https://www.siena.cx

Siena is the Agent of Record for consumer brands. One agent that owns the entire customer journey, running on a shared intelligence layer no point tool can replicate.

Consumer brands run ten or more disconnected tools to manage their customers. We collapse that stack into a single agent. It started with support, the hardest surface a brand has, and it expands from there: Shopping Agent, Social Agent, Siena working alongside a brand's own operators. One agent across every surface, with shared memory, shared context, and shared tools.

Hundreds of brands already run real customer volume on Siena in production. This is built, working, and growing, and we are racing to build what comes next.

THE TEAM

We are a small, fully distributed, global team. We have built leverage into how we work, which is what lets a team this size move at the speed we do.

We hire athletes. Everyone here owns real outcomes, defaults to writing over meetings, communicates with directness, and acts the moment they see something worth acting on. Low ego, high standards, fast clock.

If you want to own real problems rather than close tickets, keep reading.

THE ROLE

You take the hardest problems our customers hit in production and solve them end to end. A webhook that stopped firing overnight. An agent filling the wrong parameter. A report that won't reconcile. Today those land on a product engineer's desk and pull them off the roadmap. That stops with you.

- More than troubleshooting. You find the real cause, work the customer directly to a resolution (including jumping on a call when that's fastest), then build the automation so it never comes back.

- You're an accelerator. Every fix makes the next one faster and the product better.

- A clear path forward. This is the front door to deployment and platform work at Siena. Grow from here into a Forward Deployed Engineer or deeper into platform engineering.

WHO YOU ARE

- You solve problems end to end. Given a customer, some logs, and a vague symptom, you find the break and tell a customer-side cause from a product bug. You don't stop at "it's not our bug."

- You like talking to customers. You'll get on a call, find the real problem behind the report, and resolve it live. Customer contact is leverage, not a chore.

- You're excited to build automation. The fix in front of you is half the job. Building the thing that means nobody fixes it again is the other half. You think in leverage. This is the signal that matters most.

- You're fluent with AI agents and prompts. You've built or debugged LLM workflows and know how they break: prompts, knowledge bases, intent classification, retrieval, and the gap between what passes in test and what runs live. You can read a prompt, spot why it misfires, and rewrite it. No black boxes.

- You read and reason through code. You're comfortable in our core stack — Node.js, TypeScript, React, Express — or close enough to ramp fast. You can trace customer-side JavaScript in the browser, write diagnostic SQL against PostgreSQL, and navigate a backend service without waiting on someone else.