Senior Agent Design Engineer

PolyAI is the Agentic Dialog Platform for building the conversational enterprise, used to build, run, govern, and improve dialog agents at scale. Powered by Raven, a proprietary dialog model trained on more than a billion enterprise conversations, PolyAI agents are built for complexity, open at every layer, and sovereign by design. PolyAI serves hundreds of enterprises across 75 languages and 25 countries, including Metro Bank, Marriott, PG&E, and UniCredit. We're looking for a Senior Agent Design Engineer to lead the hardest agent work we take on, and to raise the bar for everyone building alongside them. This is a senior individual contributor role for someone who sits comfortably at the intersection of conversational UX design and technical implementation - someone who thinks critically about how conversations should feel, not just how systems should work. At PolyAI, Agent Design means owning the full picture: mapping user journeys, shaping dialogue and tone, and building the underlying systems that power them - prompting, tool access, and context engineering. If you've spent your career frustrated by the artificial gap between design and engineering, this role was built for you. What you'll do Lead the hardest agent work. Our most complex, ambiguous, and high-risk initiatives - spanning multiple teams, markets, or strategic accounts - and get them live faster than anyone expects. Build and own agentic workflows. Multi-agent loops, automated evaluation pipelines, autonomous tooling; designed and built end-to-end. Set the quality bar. Reusable design approaches, evaluation methods, and measurement that improve outcomes well beyond your own projects. Own client enablement. Run client and partner onboarding, and shape how the wider team enables customers to self-serve. Raise the team and influence direction. Mentor Agent Designers at multiple levels, own an area of our Agent Design roadmap, and turn recurring delivery problems into priorities for Product and Engineering. What we're looking for Required • 5+ years in a technical or design adjacent role at a tech company, with genuine hands-on experience - whether you came from design and grew into technical depth, or from engineering and developed strong UX and language sensibility • Python you can build in, not just read. You can build, test, debug, and deploy integrations yourself, and meaningfully review what others ship • Demonstrable impact beyond your own projects: patterns other people adopted, an evaluation approach that spread past the work you built it for, colleagues who got materially better because of reviews you ran • Familiarity with LLMs in practice: prompt engineering, tool use, retrieval, context management • Hands-on experience building agentic systems - orchestration, tool-calling, multi-step workflows - and, just as importantly, evaluating them: automated evaluation pipelines and measurement of non-deterministic behaviour • Experience owning external client relationships: challenging unclear requirements and explaining design decisions and trade-offs directly to customers • Meticulous attention to language, tone, consistency, and interaction quality - with the judgement to know when to resolve ambiguity and when to ship anyway Preferred • Voice-specific craft: designing around latency, barge-in, ASR errors, and recovery • Experience enabling non-technical users to self-serve on a platform • Knowledge of or aptitude for analytics or data science, including data manipulation, analysis, and visualisation • Background in Linguistics, Interaction Design, Human-Computer Interaction or a related field The listed expectations reflect what we're hiring for, so we encourage you to review the job description carefully. We provide a competitive salary range for this role - which is $110,000 – $125,000 - depending on level and experience. Candidates based in certain locations may be eligible for additional location based compensation. Please note this range is intended as a guide, not a guarantee. Final compensation will be based on individual qualifications, relevant experience, and the scope of the role. In addition to salary, this position includes equity in the business, giving you the opportunity to share in the company’s long-term success. The listed expectations reflect what we're hiring for, so we encourage you to review the job description carefully. Benefits 💰 Participation in the company’s employee share options plan 🏥 100% of Single Cost (employee) and 70% of Dependent for medical, dental & vision 👪 Life Insurance ◻️ STD and LTD 💰 The opportunity to contribute to the company's 401k plan 🏝 Flexible PTO policy + 11 designated company holidays 📚 Annual learning and development allowance 🏡 We’re all about making WFH work for you - that’s why you’ll receive a one-off WFH allowance when you join. Offering perks like noise-cancelling headphones or a comfortable desk chair to boost your comfort and focus! 🧡 Enhanced parental leave 👨‍👩‍👧 Company-funded fertility and family-forming programmes 🌸 Menopause care programme with Maven At PolyAI, we take great pride in our values - they guide everything we do. We believe that a strong culture leads to meaningful work and lasting impact. Our core values are: Only the best We expect the best from our people, we hire people that expect the best from themselves, and we nurture this drive for excellence. Ownership We care deeply about what we do. We take ownership of our initiatives, decisions and outcomes. Relentlessly improve We demand more from ourselves and are always evolving. Continuous, obsessive improvement is the only way we will transform the world of conversational AI. Bias for action Our world moves quickly and so do we. We take calculated risks and we deliver impact fast. Disagree and commit We are all working toward the same goal. If we donʼt agree with something, we work hard to understand it and when a decision is made, we accept it and give it our all. Build for people We want the world to enjoy the experiences they have with us. We are building for a future that prefers automation. PolyAI is proud to be an equal-opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. All employment decisions at PolyAI will be based on the business needs without attention to ethnicity, religion, sexual orientation, gender identity, family or parental status, national origin, neurodiversity status or disability status. Kindly find the Privacy Notice for our recruitment process by following the link here. This document provides important information regarding how we handle your personal data throughout the recruitment journey.