Senior Machine Learning 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.

As a senior Machine Learning Engineer specialising in speech recognition, you will play a key role in shaping and implementing strategies for (synthetic or not) data generation, collection, and annotation, as well as evaluating and experimenting with various models and novel architectures. Your primary focus will be on Automatic Speech Recognition (ASR), Text to Speech (TTS), and AudioLLMs (LLMs that take audio as input).

Responsibilities:

• Train models and conduct experiments to assess model performance in live deployments
• Generate, collect, and annotate contact center data from sources such as real customer calls, chats, online open datasets, and synthetic data.
• Develop strategies to achieve state of the art performance on domain-specific tasks: improving perceived latency, turn taking behaviour, accuracy of specific data points extraction (addresses, phone numbers, postcodes etc).
• Develop robust evaluation benchmarks to track improvements in production models
• Stay informed about the latest advancements in machine learning, ASR, TTS, and LLM to continuously enhance our technologies
• Build tooling which allows cooperation between clients/users of the machine learning models and MLEs (data pipelines, automated evaluation, training and deployment routine, AB testing frameworks etc).
• Collaborate with the legal and compliance team to address any compliance or data privacy-related issues
• Work closely with product and engineering teams to ensure alignment with business and production goals

Requirements:

• A degree in Computer Science, Machine Learning, or a related field, or equivalent industry experience
• 3+ years of experience working with deep learning and statistical models
• Strong knowledge of data quality standards and annotation processes, with the ability to independently evaluate and improve models
• Proficiency in Python and familiarity with relevant ML frameworks and libraries (e.g., PyTorch)
• Experience with cloud services such as AWS, GCP, or Azure
• Excellent verbal and written communication skills, with the ability to convey complex technical concepts to diverse audiences
• A passion for solving technical challenges and driving practical solutions

Preferred Qualifications:

• Experience working with LLMs and data preparation pipelines.
• Experience with speech models, such as ASR or TTS.

PolyAI Benefits - UK

💰Participation in the company’s employee share options plan

🏝25 days holiday, plus bank holidays

🏡Flexible working from home policy plus a one-off WFH allowance when you join

🌎Work from outside of the UK for up to 6 months each year

🧡Enhanced parental leave

📚Yearly learning budget

🚲Bike2Work scheme

🏥Private healthcare and dental cover, discounts on gym members and relaxation apps, and access to a range of mental health programs

PolyAI Benefits - US

💰Participation in the company’s employee share options plan

🏥100% of Single Cost (employee) and 50% of Dependent for medical, dental&vision

👪Life Insurance

◻️STD and LTD

💰The opportunity to contribute to the company's 401k plan

🏝Flexible PTO + 11 designated company holidays

📚Annual learning and development allowance

🏡One-off WFH allowance when you join

🧡Enhanced parental leave

Interview Process

TA Call - 30 mins max, basic intro call to kick things off

1. CoderPad challenge

2. Loop stage:

- 1x coding, 45 mins

- 2x machine learning, 45 mins

3. Final interview, 45 mins