Siena - Platform Experience Engineer

About the role

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. The hire will troubleshoot live customer issues directly with brands, diving into webhooks, parameters, and reports to resolve problems end to end. They will act as the primary accelerator, turning each fix into durable automation that prevents recurrence. This position owns the critical bridge between raw customer data and product decisions, ensuring insights drive measurable improvements. The role is the front door to deployment and platform work, guiding growth from operational firefighting to scalable solutions. Success means the product visibly gets better with every interaction the team resolves.

Key facts

What you'll do

• Own the hard problems end to end, tracing, reproducing, fixing, or handing engineering a clean reproduction across APIs, integrations, customer-side JavaScript, agent behaviour, and data.
• Debug the agents and the prompts, diagnosing whether a wrong answer or misfire originates in prompt design, knowledge base, configuration, or model behavior, then fixing the setup so it holds under real traffic.
• Build so it doesn't happen twice by owning two questions for every fix: can the team handle the next incident with a runbook or tool, and what do we build so the system catches the next one, compounding leverage over time.
• Close the loop to Product by acting as the structured, metrics-backed signal between what customers hit in the wild and what we build next, surfacing patterns instead of one-offs to make the product measurably better.
• Raise the team's floor by lifting what the whole team can resolve, documenting paths and outcomes so teammates gain capability rather than relying on a single expert.
• Know where your scope ends by escalating genuine product bugs, infrastructure issues, and outages with a clean reproduction and context, avoiding shrugging responsibility.
• Get on calls when that is the fastest path to resolution, using direct customer contact as leverage to understand root cause and deliver timely outcomes.
• Use AI coding tools as leverage, employing fluent Claude Code or equivalent capabilities to script queries, clean datasets, and navigate new codebads quickly while applying judgment about when to automate.

Requirements

• You solve problems end to end, finding the break given a customer, some logs, and a vague symptom, and you distinguish a customer-side cause from a product bug without stopping at "it's not our bug."
• You like talking to customers, getting on calls to find the real problem behind the report and resolving it live, treating customer contact as leverage rather than a chore.
• You are excited to build automation, recognizing that the fix in front of you is half the job and building the thing that means nobody fixes it again is the other half, thinking in leverage at every step.
• You are fluent with AI agents and prompts, having built or debugged LLM workflows and understanding how they break across prompts, knowledge bases, intent classification, retrieval, and the gap between test and live behavior, able to read a prompt, spot why it misfires, and rewrite it without relying on black boxes.
• You read and reason through code comfortably, navigating our core stack of Node.js, TypeScript, React, and Express, or ramping to that level quickly, tracing customer-side JavaScript in the browser, writing diagnostic SQL against PostgreSQL, and exploring a backend service without waiting on others.
• You use AI coding tools as leverage, fluent with scripting and dataset cleaning while applying sound judgment about when automation adds value, rather than relying on syntax recall.
• You own problems nobody assigned you, having worked where processes were thin, spotted something broken, and driven it to a fix without waiting for an explicit assignment.
• You make people around you better by leaving teammates more capable through clear documentation, reusable tools, and walkthroughs that elevate the whole team.

Nice to have

• Observability tooling experience with Grafana, Honeycomb, or Sentry.
• Internal tooling that turned manual work into a system.
• Ecommerce or DTC exposure, which is a plus but not a requirement.

Practical notes

This role is full-time and remote. No specific hours, travel, or visa details are stated in the source. The position is open to accelerate deployment and platform growth as the team races to build what comes next for hundreds of brands already running real customer volume on Siena in production.