Product Manager, Agent Platform

Sierra Ventures; España; Remote; EUR 107,000 - 160,000; Full time

Job summary

Siena runs customer experience for consumer brands through a connected multi-agent stack. As Product Manager, Core Agent Platform, you'll own the platform those agents run on, from its current capabilities to where it goes next.

You'll work directly with engineering, deployment and customers, and you'll be expected to build as well as specify. You'll design experiments, measure agent performance, and ship features that customers see and rely on.

Qualifications

• 3+ years as a PM in CX, ecommerce, helpdesk or AI automation.
• Technical fluency: explain webhooks, OAuth and integrations.
• AI-native builder: using Claude, Cursor or v0 and prototyping ideas.

Responsibilities

• Own the core agent platform end to end, including roadmap and day-to-day decisions.
• Build and ship evaluation, testing and monitoring systems for better agent performance.
• Design and run structured experiments and A/B tests across agent workflows.
• Provide customers visibility into agent performance.
• Prototype ideas with coding agents and ship where possible.
• Collaborate with customers and deployment to translate field insights into product.

Skills

PM experience

Technical fluency

AI-native builder

Tools

Webhooks

OAuth

Integrations

Job description

Meet Siena

Siena is the Agent of Record for CX, built for consumer brands like Spanx, FIGS, Brooklinen, and Grüns.

It runs as a connected multi-agent stack on top of a shared intelligence layer: agents that sell, support, listen, handle social and voice across the entire customer journey, turning every conversation into signal you can act on.

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 set the bar rather than follow one, keep reading.

The Role

Siena runs customer experience for consumer brands through a connected multi-agent stack. As Product Manager, Core Agent Platform, you'll own the platform those agents run on, from its current capabilities to where it goes next. You'll own how we measure, test and improve agent performance, and how customers see it. You'll work directly with engineering, deployment and customers, and you'll be expected to build as well as specify.

What You'll Do

• Own the core agent platform end to end, including the roadmap and the day-to-day product decisions.

• Build and ship the evaluation, testing and monitoring systems that make agent performance measurably better over time.

• Design and run structured experiments and A/B tests across agent workflows.

• Give customers clear visibility into how their agents are performing.

• Prototype your own ideas with coding agents, and ship them where you can, rather than waiting on a hand-off.

• Work with customers and our deployment team to understand what's working in the field and turn it into product.

Who You Are

The Bar: If you're missing any of these, this isn't the role for you.

• 3+ years as a PM in CX, ecommerce, helpdesk or AI automation.

• Technical fluency: you can explain how webhooks, OAuth and integrations work and have made product decisions around them.

• AI-native builder: you use tools like Claude, Cursor or v0 daily and have prototyped your own product ideas with them.

Strong Signal: Not dealbreakers, but what separates a good hire from a great one.

• You've run structured experiments or A/B tests and can say what the data did and didn't tell you.

• You've built dashboards or visibility features people actually relied on.

• You're confident with customers: you've sat in on calls, run demos, and know what end users really complain about.

• You're confident with customers: you act like the CEO of your product area: strong opinions, and a habit of building and talking to customers without being asked.

Nice to Have: Bonus, not required.

• Engineering background, or you've shipped production code yourself.

Not a Fit If:

• You wait to be told what to build.

• You want a narrowly scoped PM seat with a fixed roadmap handed to you.

• You're not comfortable being customer-facing or getting on a call to demo your own work.

• You'd rather stay behind the product than own the messy, ambiguous parts.

• You need a designer or engineer to turn your product vision into something people can click.

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. But the magic happens in how we share knowledge. Demo days where someone shows off a 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.