Senior Full Stack Engineer

PolyAI automates customer service through lifelike voice assistants that let customers lead a conversation. Our voice assistants make it possible for businesses to deliver outstanding customer service that rivals their human agents. Our customers, which include the world’s leading logos, are expanding how they use our platform, driving automation of critical customer service operations and integrating PolyAI into their daily customer service workflows.

We are seeking an experienced Senior Full Stack Developer (backend-focused) to join our team and shape our cutting‑edge low‑code platform. In this role, you’ll work end‑to‑end, from design to implementation, on features that make it easy for users to interact with complex AI systems. You’ll also play a key role in mentoring junior engineers and guiding technical decisions.

If you’re passionate about Python and great API design, or love working with React to build intuitive tools that empower non‑technical users to harness AI, we’d love to hear from you!

• Architect and Develop:
  Design and implement our external‑facing API that enables developers to build, manage, analyse, and interact with our agents. Help to build and enhance our no‑code platform, enabling non‑technical users to configure sophisticated dialogue systems and voice experiences.
• Full‑Stack Development:
  Design and implement features end‑to‑end, using Python for backend services and React (Next.js preferred) for frontend interfaces.
• Create intuitive interfaces:
  Build user‑friendly APIs and UIs that simplify and visualise complex AI concepts.
• Champion Best Practices:
  Lead the team in adopting coding standards and best practices, ensuring a clean, maintainable, and scalable codebase.
• Collaborate:
  Work closely with cross‑functional teams to design, develop, and deliver features that align with the platform’s vision.
• Mentor and Guide:
  Provide technical leadership and guidance to junior engineers, fostering a collaborative and growth‑oriented environment.
• Optimise Performance:
  Improve backend workflows, streamline processes, and enhance overall system efficiency.

• Proven Expertise in Python: 5+ years of extensive experience building backend systems, with a strong understanding of REST APIs (experience with Web Sockets is a plus).
• Front‑end Proficiency:
  Strong experience with React and JavaScript (Type Script preferred); experience with CSS‑in‑JS and utility‑first CSS frameworks (e.g., styled‑components, Tailwind CSS).
• Agile Practitioner:
  Familiarity with Agile methodologies such as Scrum or Kanban.
• Testing Advocate:
  Experience writing and maintaining unit tests in Python and JavaScript (Jest, React Testing Library, Playwright).Security‑Minded:
  Experience managing secure communication protocols between client and server.
• Version Control:
  Proficiency with Git for collaborative development.
• Additional Skills (Desirable):
  Knowledge of Go and experience with Next.js.

We provide a competitive salary range for this role: $170k – $200k, depending on level and experience. 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.

• 💰 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 we offer 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…