Seller and Onboarding Manager - Marketplace in England

We’d all like amazing work to do, and real work-life balance. That’s waiting for you at Sainsbury’s. From fragrance to car care, clothing and pots and pans, our General Merchandise team delivers all the non-food items for Sainsbury’s, Habitat and Argos customers. This multi-brand environment means you get to work across most areas. You can also be a pioneer, because the team believes in being brave, iterating and learning as they go. They also develop deep connections to other departments, which opens up a lot of different career opportunities for you. What’s certain is that you’ll spend time on the shop floor to get closer to customers, and bring a broad perspective and the full support of your manager with you wherever you decide to develop next.

Location: Ansty store support centre or London store support centre

In a nutshell: To lead and continuously improve the end-to-end onboarding experience for new sellers and their products onto our Ecommerce marketplace platform, ensuring a seamless, compliant, and scalable process that drives seller success and supports the marketplace’s growth ambitions. This role is pivotal in enabling sellers to launch quickly and effectively, contributing directly to the platform’s commercial and customer experience goals.

What I Am Accountable For:

• Manage end-to-end onboarding process for new sellers from contract signature through to first sale
• Guide sellers through platform setup, including configuration, catalog integration, and technical requirements
• Train sellers on marketplace platform functionality, best practices, and operational workflows
• Coordinate with internal teams (legal, finance, operations, tech support) to ensure smooth onboarding, resolve onboarding issues and continuously improve processes
• Troubleshoot technical issues and resolve seller questions during onboarding phase identifying pain points to drive future improvements.
• Monitor onboarding timelines and KPI’s, proactively address blockers to meet go-live targets
• Ensure sellers meet quality standards and compliance requirements before launch
• Develop, implement, and optimise the seller and product onboarding process documentation, templates, and training materials ensuring efficiency, compliance with all regulations and policies, and delivery of a positive seller experience
• Conduct regular check‑ins with sellers during onboarding to track progress and provide support
• Gather seller feedback to identify process improvements and optimise onboarding experience
• Report on onboarding metrics including time-to-live, completion rates, and bottlenecks
• Lead, coach, and develop the onboarding team to deliver high‑quality support and guidance to new sellers
• Act as the escalation point for complex onboarding cases, making decisions on exceptions and process changes as needed
• Communicate regularly with internal and external stakeholders to align on onboarding priorities and initiatives
• Coach and develop Direct reports and colleagues to achieve their best potential

Key Performance Measures:

• Seller onboarding completion rates and time-to-live
• Seller satisfaction/NPS scores post-onboarding
• Compliance and quality metrics for new listings
• Reduction in onboarding-related support tickets
• Team engagement and development

What I Need To Know:

Essential:

• 2-4 years in customer success, account management, operations, or onboarding roles
• Experience with e-commerce platforms or marketplace technologies
• Strong project management skills with ability to manage multiple onboarding projects simultaneously
• Excellent written and verbal communication skills with ability to explain technical concepts clearly
• Technical aptitude and comfort with APIs, integrations, and troubleshooting platform issues
• Understanding of UK/EU product safety, quality, and legal standards; ability to implement technical compliance checks.
• Competence in using dashboards, KPIs, and performance metrics to monitor onboarding success and seller performance.
• Detail‑oriented with strong organisational and documentation skills
• Customer‑centric mindset with patience and problem‑solving abilities
• Proficiency with CRM and project management tools
• Ability to work cross‑functionally and coordinate with multiple stakeholders
• Proactive and resourceful in resolving issues independently
• Proven people management and leadership skills, demonstrating confidence in broad stakeholder and matrix team management

Desirable:

• Proven experience as a Marketplace Integration Specialist
• Project management qualification or experience
• Experience working in a fast‑paced, high‑growth environment

Benefits:

We are committed to being a truly inclusive retailer so you’ll be welcomed whoever you are and wherever you work. Around here, there’s always the chance to try something new — whether that’s as part of an evolving team or somewhere else across the business - and we take development seriously and promise to support you. We also recognise and celebrate colleagues when they go the extra mile and, where possible, offer flexible working. When you join our team, we’ll also offer you an amazing range of benefits. Here are some of them:

• Starting off with colleague discount, you'll be able to save 10% on your shopping online and instore at Sainsbury's, Argos, TU and Habitat, and we regularly increase the discount to 15% at points during the year.
• We've also got you covered for your future with our pensions scheme and life cover.
• You’ll also be able to share in our success as you may be eligible for a performance‑related bonus of up to 20% of salary, depending on how we perform.
• Your wellbeing is important to us too. You'll receive an annual holiday allowance, and you can buy up to an additional week's holiday, and we provide private healthcare.
• We also offer other benefits that will help your money go further such as season ticket loans, interest free car loan of up to £10k, cycle to work scheme, health cash plans, salary advance where you can access some of your pay before pay day as well access to a great range of discounts from hundreds of other retailers.
• And if you ever need it there is also an Employee Assistance Programme.
• Moments that matter are as important to us as they are to you which is why we give up to 26 weeks’ pay for maternity or adoption leave and up to 4 weeks’ pay for paternity leave.