Overview
Who are OnBuy?
OnBuy is an innovative online marketplace dedicated to being the best choice for every customer, everywhere. Recently recognized as one of the UK’s fastest-growing tech companies by the Sunday Times 100 Tech list, we take great pride in our achievements while remaining focused on our mission.
Working at OnBuy:
Our team is made up of driven and motivated individuals who excel in a fast-paced environment. To thrive at OnBuy, you’ll need to take initiative and fully own your responsibilities, ready to roll up your sleeves when necessary. At OnBuy, you will have the opportunity to affect meaningful change and ensure your voice is heard within a cohesive team eager to learn and grow together.
About the Role
We are on a journey to build a more intelligent and scalable product catalogue across diverse markets. While core capabilities like auto-categorization and brand detection exist, we are looking for someone to integrate these systems to consistently enhance quality, discovery, and growth.
As a Senior Applied ML Engineer – Catalogue Intelligence, you will own and develop the machine learning systems that power OnBuy’s catalogue decision-making engine. Collaborating with the Head of Seller Solutions, who outlines catalogue rules and commercial logic, you will design and deploy production-grade systems aimed at improving:
Product categorizationData quality and completenessInsights into pricing competitivenessCatalogue coverage and selectionProduct discoverabilityYour work directly impacts our live catalogue and plays a crucial role in enhancing GMV, conversion performance, and overall discovery.
Core mission
Transform catalogue rules and commercial logic into automated, data-driven systems that continuously enhance product discoverability, data quality, pricing competitiveness, and revenue outcomes.
Key Responsibilities
You will take charge of how product data is structured, validated, and utilized across our platform. Your responsibilities will include:
Enhancing product classification and understanding at scaleElevating the quality of catalogue data and establishing benchmarks for excellenceEnsuring product data facilitates effective search, filtering, and discoveryIdentifying gaps in our catalogue and recognizing opportunities for growthMaximizing catalogue performance across external channelsBuilding and evolving systems and decision logic based on real-world performance and analyticsYou will be working with:
Structured data (catalogue attributes, GTINs, taxonomy)Unstructured data (text and images)Behavioral data (search activities, clicks, conversions)How You’ll Work
Your work will involve building directly with SQL and Python, utilizing:
BigQueryAirbyteGoogle DatastreamYou’ll engage with data pipelines, information extraction, and production ML systems, blending rules, heuristics, and machine learning where appropriate. The focus is on rapidly deploying practical systems, validating them with real data, and iterating for improvement. You’ll closely collaborate with engineering, product, and analytics but will be expected to independently deliver core logic.
Ideal Candidate
Proven experience building and deploying production data or ML systems that have measurable business impactStrong proficiency in Python and SQL, capable of managing end-to-end data pipelinesAdept in applying modern methodologies such as LLMs, multimodal models, and information extraction techniques, transitioning them from experimentation to production with appropriate evaluation and monitoringExperience handling messy, unstructured, or semi-structured data (e.g., text, images, product data)Capacity to design decision-making systems, not just prediction modelsInsightful judgment in weighing accuracy, risk, and business impactFamiliarity with ecommerce or marketplace catalogues is a plus, but not mandatoryOperational Approach
Own problems from inception to production impactCreate scalable, testable, observable, and auditable systemsDesign automation with monitoring and feedback loopsMaintain clear documentation, evaluation frameworks, and versioning for models and logicWork pragmatically to deliver impactful, straightforward solutions quicklyEffectively communicate trade-offs to both technical and non-technical stakeholdersComfortable working in dynamic environments where data is constantly evolvingExperience with cloud-based data systems (GCP) is essential, including building data pipelines and deploying production ML workflows. Familiarity with orchestration tools (e.g., Airflow) and CI/CD practices is beneficial.The salary for this role is between £65,000 and £75,000, depending on your experience.
Additional Benefits:
Company equity – as a thank you for your contributions to our growth, you will receive company equity, giving you a stake in our joint success.25 days of annual leave plus Bank Holidays1 extra day off for your BirthdayEmployee Assistance ProgrammeAccess to a Perks at Work benefit platformCareer development and progression opportunitiesThis role can be performed remotely or hybrid if you are near our offices in Manchester or Bournemouth.
Please only apply if you have the full right to work in the UK.
Our Commitment
OnBuy is an equal opportunities employer. We are dedicated to creating a fair and transparent workforce, ensuring our recruitment process does not discriminate based on gender, sexual orientation, marital or civil partnership status, pregnancy or maternity, gender reassignment, race, color, nationality, ethnic or national origin, religion or belief, disability, or age.
Please be aware that we never use WhatsApp or any messaging apps to contact candidates. If you are contacted this way, it is not us, and we encourage you to inform our recruitment team.
Company:
OnBuy
Qualifications:
Language requirements:
Specific requirements:
Educational level:
Level of experience (years):
Senior (5+ years of experience)
About OnBuy
OnBuy is an online marketplace connecting buyers and third-party sellers across various product categories.
