Solutions Engineer - Remote in London

Meet Siena. Siena is the Agent of Record for consumer brands. One agent that owns the entire customer journey, running on a shared intelligence layer that 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 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.

About The Role

This is a hands‑on Solutions Engineer role — the second SE on a small, high‑output GTM team. You will own the technical side of deals end to end: from first demo and integration scoping, through multi‑week proof‑of‑concept trials, to the technical green light that lets a deal close.

What You’ll Own

• Technical pre‑sales & demos: Run demos built around the prospect's actual problems and data across our Support, Shopping, Social, Reviews, and Voice agents and Siena Intelligence. Lead live technical discovery and validation: map the prospect’s stack, answer “can it do X?” honestly, and propose solutions when the standard product doesn’t fit. Maintain and refresh the demo environment and demo asset library (live demos, video assets, scenario flows) so the whole GTM team can sell accurately. Assist with RFPs and security questionnaires.
• Proof‑of‑concept & trial ownership: Own multi‑week POC/trial programs end to end: kickoff, integration connect, journey and automation buildout, weekly working sessions, QA, troubleshooting, and final readout. Write clean technical handoffs so Deployment can carry the customer past go‑live.
• Integration scoping & solution design: Scope integrations across the e‑commerce CX stack; decide native‑vs‑custom build and partner with Engineering on what gets built. Build and test integrations yourself — write custom actions, test and validate in Postman against live or sandbox endpoints. Draft, scope, and price Statements of Work for custom configuration and integration work, and translate feasibility into realistic effort and cost.
• Cross‑functional & product feedback: Be the connective tissue across Sales, Engineering, Product, and CS — triaging customer issues, filing well‑scoped Linear tickets, and escalating to the right owner. Act as the field‑to‑product feedback conduit: bring concrete product gaps and roadmap input into product reviews, grounded in real deals. Support pricing conversations with the technical ROI and volume case (the AE owns commercial terms). Contribute to internal enablement — training AEs and CSMs to demo, and building reusable enablement content.

What You’ll Need

• Pre‑sales experience. 3–5+ years as a Solutions / Sales Engineer (pre‑sales) in B2B SaaS, with a track record of personally owning demos and POCs.
• Hands‑on technical ability. Fluency with APIs, webhooks, and authentication methods; comfortable reading API docs, testing in Postman, and judging integration feasibility. You’ll need to be able to build.
• E‑commerce CX stack breadth. Working knowledge of the ecosystem: Shopify plus helpdesks (Gorgias, Zendesk, Kustomer, Dixa, or similar), and adjacent tools for returns, subscriptions, reviews, loyalty, and post‑purchase. Breadth across the stack matters more than depth in one tool.
• Clear communication. The rare ability to explain AI and technical concepts clearly to a non‑technical CX or commerce leader, and to write tight SOWs, RFP responses, and handoffs.
• Self‑direction. Comfort prioritizing across many simultaneous deals in a fast, small‑team startup — and building your own process and leverage (including with AI tooling).

Bonus Points

• Hands‑on experience configuring, prompting, or selling LLM / AI agent products.
• Experience working with contact‑center technology.
• Experience writing and pricing custom‑integration SOWs, or a forward‑deployed / implementation background.
• Familiarity with the rapidly evolving AI CX landscape.

Why Siena?

• Real ownership. You will own problems, not tasks, with the autonomy to solve them your way and the trust to do it without a manager in your inbox.
• Work that ships and matters. What you build reaches real consumer brands fast.
• A category we are creating. The Agent of Record is new ground, with unsolved problems and cutting‑edge models, not a crowded field to compete in.
• A team that respects your judgment. Globally distributed, async‑first, low bureaucracy. We hire adults and treat you like one.
• Great salary plus equity or stock grants. Own a piece of what you build.
• Learning budget. If you are growing, so are we.
• AI‑fluency by default. Few places will push your work with production AI further or faster.

Our values

The people who thrive here are curious, customer‑obsessed, and take ownership without being asked. They fix problems first and explain later. They're direct about feedback—both giving and receiving it—because they care more about getting things right than being polite. They maintain high standards while moving at startup speed, and they build real relationships with teammates because they know that's how great work gets done. When things get tough, they adapt and keep pushing forward.

Our approach to AI

The people who thrive here treat AI like a natural extension of themselves. They've built their own ecosystem of agents—some for research, others for debugging, writing, analysis, or writing code. They know which AI works best for what problem. Everyone gets premium accounts (ChatGPT, Claude, Perplexity Pro, Cursor, Lovable) plus a quarterly budget for new tools. The magic happens in how we share knowledge—demo days where someone shows off clever workflows, Slack threads about which model handles a specific use case better, learning from each other's AI workflows. At Siena, we’re not just looking for people who can do a job. We’re looking for people who want to break boundaries, create the future, and reshape industries. If that’s you, we look forward to your application.

Siena provides equal employment opportunities to all employees and applicants for employment without regard to race, color, religion, sex, national origin, age, disability, genetics, sexual orientation, gender identity, or gender expression. We are committed to a diverse and inclusive workforce and welcome people from all backgrounds, experiences, perspectives, and abilities.