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Plain is redefining customer support for the next generation of B2B companies. We’re building the fastest, most powerful platform to help companies move beyond reactive support and build true customer relationships.

B2B customer support is undergoing a seismic shift. AI is transforming the way companies engage with customers, shifting support from a siloed function to a company-wide effort across Slack, Discord, and in-product experiences. The old way – slow, manual, and disconnected – no longer works.

Some of the world’s most forward-thinking companies – like Stytch, Sanity, and Fly.io – trust Plain to unify all customer interactions, enable faster team collaboration, and supercharge their workflows with AI.

What you’ll do:

We’re in a rare position. We’ve already built a deeply scalable, lightning-fast support platform that high-growth companies love. AI has been at the core of our product for a while now – but now, we want to take it to the next level. We have the opportunity to define how AI powers customer support at every level, from automating workflows to deeply understanding customer needs.

This is where you come in. We’re looking for a sharp, fast-moving, and customer-obsessed Founding AI Engineer to accelerate our AI ambitions. This is a rare chance to shape the AI strategy of an early-stage, high-impact product and help build a category-defining company.

In this role, you will:

• Define our AI infrastructure and play a key role in shaping our AI strategy.
• Own and ship AI-powered features from concept to production.
• Solve complex machine learning challenges – especially around AI accuracy, reliability, and quality – using a rigorous, truth-seeking approach.
• Serve as the team’s AI expert, helping to build a world-class AI practice.
• Advocate for our work externally – writing, speaking, and engaging with the broader AI community.

This is a great fit if you:

• Are an experienced backend engineer who’s built AI products in the OpenAI & Anthropic era – especially text- and data-heavy AI applications.
• Have AI observability experience. AI isn’t just about shipping features that sound great – it’s about knowing, conclusively, if they’re making things better.
• Have a clear perspective on what makes a great AI-powered product. We want to apply AI with precision, nuance, and real impact – not as a gimmick.
• Are self-driven, impact-focused, and thrive in a fast-moving, high-ownership environment.
• Measure your success by user impact, not just technical elegance.
• Bonus: You have a data science background that helps you fine-tune AI accuracy and quality.

This won’t be the right role if you:

• Have only academic or research ML/AI experience. We need someone who’s applied AI to real products, not just explored theoretical models.
• Think AI for support is just chatbots. B2B support is complex – we’re AI-powering the entire platform, not just automating conversations.
• Struggle with ambiguity. We’re an early-stage startup. Things change quickly, and often, knowing what to work on is as important as the work itself.
• Prioritize working with the latest tech for its own sake. We choose tools that make us productive – not what’s trendy. (Postgres is great.)
• Are looking for a management role. This is a hands-on individual contributor position.
• Want the perks of a big company. We offer competitive compensation for our stage, but we’re a startup – this is a different kind of opportunity.

Note: We are an equal-opportunity employer and remote-only company. At this time, we can only support hiring within Europe for this role.

Compensation Range: £75K - £130K

Mid-Senior level

Full-time

Engineering and Information Technology

Software Development