Senior Machine Learning Scientist - Remote Opportunity

About the Role

We're hiring a Senior Machine Learning Scientist to join our team and help build and ship the next generation of our AI-powered Customer Experience Intelligence platform. This role offers the flexibility of working remote or in a hybrid setup, depending on your preference. As a Senior Machine Learning Scientist, you'll play a critical role in shaping the future of customer feedback analysis for major brands like Uber and Amazon.

What You'll Do

• Train, evaluate, and iterate on ML models and agentic systems for customer feedback, including owning our custom fine-tuning pipelines.
• Run experiments end-to-end, track results rigorously, and make clear recommendations on what to ship, iterate, or retire.
• Build and maintain LLM-powered features: retrieval pipelines, reranking systems, insight agents, data mining agents, and automated taxonomy generation.
• Design and run robust evaluation frameworks: build test sets, define metrics, evaluate non-deterministic systems, handle class imbalance, and automate checkpoint comparisons.
• Improve and extend semantic search and retrieval, evolving from embedding-based approaches toward more advanced methods.
• Write production-quality code and collaborate closely with Engineering on productionisation, model serving, data pipelines, and monitoring.
• Work with Product and Commercial teams to translate business needs into practical ML solutions, and support client evaluations and accuracy benchmarking.
• Mentor team members, review code and research, and bring relevant advances from the literature into the product.

Requirements

• A deep working knowledge of transformer architectures.
• Strong PyTorch skills, with the ability to write custom training loops, modify model architectures, and debug issues at the tensor level.
• Experience with parameter-efficient fine-tuning techniques such as LoRA.
• Extensive experience working with large-scale, messy real-world text data, including classification, extraction, embeddings, re-rankers, clustering, and search.
• Experience in instruction fine-tuning and serving language models, familiarity with frameworks such as vLLM, DeepSpeed, or similar tools.
• A solid grounding in classical ML and statistics, and the judgement to choose simpler methods when they’re the right solution.
• Practical experience building with GenAI and agentic patterns.
• Excellent communication skills and confidence translating complex technical concepts for non-technical audiences.

Nice to Have

• MSc/PhD in Computer Science, Machine Learning, Artificial Intelligence, Data Science, Computational Linguistics or a closely related STEM field.
• Experience with reinforcement learning techniques, such as with verifiable reward (RLVR).

What We Offer

• Monthly Health & Wellness budget, increasing with length of service.
• Annual Learning and Development budget, increasing with length of service.
• Flexible working in a choice-first environment.
• Work From Home Allowance.
• 25 Holiday Days + your local bank holidays, plus an extra day for every year of service.
• Your birthday off.
• Enhanced Family Leave (UK Only), Fertility Leave, and Neonatal Leave.
• Optional Healthcare Plan.
• Life & income protection (Location dependent).
• Employee Assistance Programme (UK Only).