Remote Senior Applied Machine Learning Engineer

• Own how product data is structured, validated, and used across the platform
• Improve how we classify and understand products at scale
• Raise the overall quality of catalogue data and define what good looks like
• Ensure product data supports effective search, filtering, and discovery
• Identify gaps in our catalogue and surface opportunities for growth
• Improve how our catalogue performs across external channels
• Build and evolve the systems and decision logic that enable these outcomes, and iterate based on real-world performance and data
• Work across structured data, unstructured data, and behavioural data
• Build directly using SQL and Python on top of BigQuery, Airbyte, and Google Datastream
• Work across data pipelines, information extraction, and production machine learning systems
• Combine rules, heuristics, and machine learning or large language models where appropriate
• Ship practical systems quickly, validate them with real data, and improve them over time
• Work closely with engineering, product, and analytics while owning and delivering the core logic yourself
• Take ownership of problems end to end, from idea through to production impact
• Build systems that are scalable, testable, observable, and auditable
• Design automation with confidence thresholds, monitoring, and feedback loops in mind
• Maintain clear documentation, evaluation frameworks, and versioning for models and logic
• Work pragmatically, favouring simple solutions that deliver impact quickly
• Communicate trade-offs clearly to technical and non-technical stakeholders

Technologies:

• Airflow
• BigQuery
• CI/CD
• Cloud
• Machine Learning
• Python
• SQL
• GCP

More:

We are OnBuy, an online marketplace on a mission to be the best choice for every customer, everywhere. We have recently been named one of the UKs fastest-growing tech companies in the Sunday Times 100 Tech list, and we are proud of what we have achieved while staying focused on the work ahead. We are a driven, motivated, close-knit team that thrives in a fast-paced, constantly evolving environment where you can take ownership, have your voice heard, and make meaningful change. This Senior Applied ML Engineer - Catalogue Intelligence role is a hands-on, production-focused position responsible for building the machine learning systems behind our catalogue decisioning engine. The role is UK remote, or hybrid if you live near our Manchester or Bournemouth offices, and we offer company equity, 25 days annual leave plus Bank Holidays, an extra day off for your birthday, an Employee Assistance Programme, Perks at Work, and opportunities for career development and progression. We are an equal opportunities employer and are committed to a fair and transparent recruitment process.

• Experience building and shipping production data or machine learning systems with measurable business impact
• Strong Python and SQL skills, with the ability to work across data pipelines end to end
• Comfort applying modern approaches such as large language models, multimodal models, and information extraction techniques, and taking them from experimentation into production with proper evaluation, monitoring, and cost control
• Experience working with messy, unstructured, or semi-structured data such as text, images, and product data
• Ability to design systems that make decisions, not just predictions
• Strong judgement in balancing accuracy, risk, and business impact
• Experience with e-commerce or marketplace catalogues is a plus, but not required
• Experience working in cloud-based data systems, particularly Google Cloud Platform, building and deploying data pipelines and production machine learning workflows is beneficial
• Experience with orchestration tools such as Airflow or similar, CI/CD, and model deployment practices is beneficial