Senior People Business Partner in London

About Stacks

Stacks is building an AI‑native platform that reinvents how modern finance teams run the monthly close. The opportunity is massive: every growing company depends on accurate, timely financial data, yet most are still operating with tools and workflows built for a different era. In just two years, we've grown from a team of 2 to 30+ and are on a rapid trajectory. We've raised a $23m Series A led by Lightspeed Venture Partners, and we were recently recognised as one of Harmonic's Hottest Startups of 2026. We're already trusted by leading European scale‑ups including Pleo, Freetrade, and Motorway.

Our team is a blend of finance, product, and technical experts from top‑tier companies like Uber, Plaid, Miro, Mollie, and Bunq, united by the drive to create a game‑changing solution. We're a team that is deeply customer‑obsessed, plays to win, and isn't afraid to take big, bold bets. We move fast, hold a high bar, and are committed to growing together as we scale.

Location: London or Amsterdam office (GB).

About the Role

Stacks is hiring a Senior People Business Partner to support our next phase of growth and help build a high‑performing, well‑supported organisation. You'll be the trusted people partner to founders and managers, helping navigate the people opportunities and challenges that come with scaling quickly. This is a hands‑on, high‑impact role focused on manager enablement, performance development, people operations, and ensuring we operate effectively across the Netherlands and UK.

We're looking for someone commercially minded, pragmatic, and highly human in their approach – someone who can bring structure, sound judgement, and empathy to important people matters. If you've supported fast‑growing companies through growth and change, enjoy coaching leaders, and know how to balance business needs with employee experience, this could be the role for you.

What You'll Do

• Partner with Leaders & Managers
  • Act as a trusted advisor to founders and managers on people matters across the business
  • Coach managers to lead high‑performing teams with clarity, accountability, and empathy
  • Support managers in identifying top performers, growth opportunities, and where additional support is needed
  • Build practical frameworks and tools that improve manager effectiveness
• Support Performance & Employee Experience
  • Partner with managers to build high‑performing, well‑supported teams
  • Help resolve people matters thoughtfully and fairly when they arise
  • Foster a culture of feedback, accountability, and development
• Drive People Operations & Compliance
  • Provide people support across the UK and Netherlands, ensuring effective and locally compliant practices
  • Own and manage our sponsorship licence processes and visa administration
  • Ensure people policies, documentation, and processes are compliant, effective, and scalable
• Partner on Reward & People Programs
  • Partner closely with Talent and leadership on compensation, benchmarking, and benefits
  • Support compensation review cycles and evolving reward frameworks
  • Help improve employee experience through strong people practices and continuous feedback

What You Need

• 5+ years of experience in People Business Partnering / HR Business Partner roles, ideally within fast‑growing tech or scaling environments
• Strong track record of coaching managers and supporting leaders through a broad range of people matters
• Solid knowledge of Netherlands employment law and people practices preferred; UK employment law experience beneficial
• Experience leading performance management processes and helping build high‑performing teams
• Strong operational mindset with the ability to bring structure, prioritisation, and pace to a growing business
• Excellent judgement, communication skills, and ability to build trust across all levels of an organisation

What's in It for You

• Foundational role: Help shape a category‑defining company from an early stage, working directly with founders and a small, high‑agency team.
• Meaningful ownership: Competitive equity in a company scaling rapidly, where your impact will directly shape the outcome.
• Cutting‑edge product and tech: Work at the intersection of AI and finance, building systems that fundamentally change how companies run their financial close.
• High‑calibre team: Collaborate with people from companies like Uber, Plaid, Miro, and Mollie.
• Exceptional workspace: Our London HQ is based in Fora – a modern, design‑led space in the heart of the city with access to a gym, classes, and an environment built for focused, in‑person building.
• Strong team culture: We run regular socials and off‑sites that bring the team together; we recently had our 2‑year anniversary party in Amsterdam with board games, a tarot card reader and live music.