Senior Software Engineer in London

PolyAI automates customer service through lifelike voice assistants that let customers lead a conversation. Our voice assistants help businesses deliver outstanding customer service that rivals human agents and integrate PolyAI into daily customer service workflows.

Responsibilities

• Building reliable APIs for interacting with the runtime of our Voice Agent deployments.
• Deploying state-of-the-art speech-to-text, LLMs and text-to-speech models.
• Taking a major role in software development, through writing code, tests, contributing to design ideas, documents and performing code reviews.
• Contributing to the implementation of our multi-tenant infrastructure.

Requirements

• 3+ years programming experience in a software engineering role, with strong proficiency in Python.
• Hands-on experience in designing, deploying, and maintaining RESTful APIs.
• Experience with professional software engineering best practices, such as coding standards, code reviews, source control, build processes, and testing.
• Understanding of algorithms, data structures, system design and complexity analysis.
• Bachelor's degree or Master's in Computer Science, Engineering, a relevant technical field or equivalent practical experience.
• Proficiency in verbal and written English communication.

Teams Runtime: own the global infrastructure that powers real-time voice interactions. You will work at the core of the agentic process – streaming audio, transcribing speech, using LLMs and acting on their output, and synthesising natural voice. You will design and optimize systems across VoIP and WebRTC to deliver low-latency, secure, and reliable conversations. Your work shapes the user experience of every call, driving down response times, improving comprehension, and ensuring we meet strict SLAs for performance and security.

Data: play a key role in delivering the next generation of our no-code agent studio platform. You will lead the design and development of features that power insight generation, reporting, and the data-driven backbone of our no-code platform for building voice assistants.

Product Engineering: help shape our cutting-edge low-code platform. This role offers the opportunity to work end-to-end, from design to implementation, on features enabling a simple user experience for interacting with complex AI systems.

Hiring process: You will go through a centralized hiring process that lets us get to know your skills and preferences, while you explore which team best aligns with your interests and expertise. At the end, we will match you with the team where you can have the most impact.

What we offer

• Competitive compensation based on experience, expertise, and the level of responsibility.
• This role also includes equity, giving you the opportunity to share in the long-term success of the business.
• Participation in the company's employee share options plan.
• Tenure-Based PTO: 25 holidays on joining, plus 1 additional day after 2 years, then 1 day each year up to 32 holidays.
• Flexible working from home policy.
• Work from outside of the UK for up to 6 months each year.
• TELUS Health EAP 24/7 - confidential support for work, health, or life challenges.
• Annual learning and development allowance.
• One-off WFH allowance to set up a comfortable workspace.
• Company-funded fertility and family-forming programmes.
• Private healthcare and dental cover, gym discounts, and access to mental health programs.
• Sabbatical Program: 5-week paid sabbatical after 5 years of employment.

Values and inclusion: At PolyAI, we take great pride in our values and culture. Our core values are:

• Only the best: we expect the best from our people and nurture excellence.
• Ownership: we take responsibility for initiatives, decisions, and outcomes.
• Relentlessly improve: we continuously evolve to transform the world of conversational AI.
• Bias for action: we move quickly, take calculated risks, and deliver impact.
• Disagree and commit: we work toward common goals and commit to decisions when made.
• Build for people: we aim to create experiences that empower users and support 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 are based on business needs without regard to ethnicity, religion, sexual orientation, gender identity, family or parental status, national origin, neurodiversity status or disability status.

Privacy notice: Kindly find the Privacy Notice for our recruitment process by following the link here. This document provides information regarding how we handle your personal data throughout the recruitment journey.