Staff Engineer; Payroll & Data at Santander-backed global fintech

Job Title

Staff Engineer — Backend (Payroll & Data)

Not Disclosed

Santander-backed global payments fintech with a recent £550M funding round

You will architect and build a greenfield, AI-native global payroll engine from the ground up. This role involves designing complex data pipelines that normalize HRIS data into a proprietary calculation engine. You will bridge the gap between HR tech and fintech by connecting automated payroll logic to existing multi-currency payment rails.

London, UK;
Madrid, Spain; or Malaga, Spain

• Founding-Level Impact:
  Build an AI-native payroll product from scratch while leveraging a pre-existing infrastructure that processes 1.9M annual payments across 130+ currencies.
• Massive Backing:
  Backed by Santander with a fresh £550M raise, providing the stability of a corporate leader with the creative freedom of a greenfield startup environment.
• Tech-Forward Stack:
  Direct a team of AI coding agents to 10x your output while owning the architecture in a modern Python, Node.js, and Type Script environment.

• Architect Data Pipelines:
  Build robust systems to pull, normalize, and transpose data from various HRIS and HCM integrations into a centralized payroll calculator.
• Develop Calculation Engines:
  Design jurisdiction-specific logic to handle complex tax, benefits, and deductions, ensuring high-fidelity output for bank files and compliance reports.
• Orchestrate Workflows:
  Create end-to-end SaaS workflows from client onboarding and approval routing to the final execution of global payments via existing rails.

• Industry Expertise:
  Proven experience building payroll engines or payment processing systems at tech-first companies like Deel, Papaya Global, or Remote.
• Technical Mastery:
  Staff-level proficiency in Python or Node.js with deep experience in data transformation, dbt, and architecting complex SaaS platforms.
• Full-Stack Capability:
  Strong backend focus but possessing enough frontend knowledge (Angular/TS) to direct junior engineers and ensure seamless product delivery.