Senior Frontend Engineer in London

Cornspring is an innovative FinTech start-up with a mission to empower Family Offices and Asset Owners with real-time, AI-driven data intelligence and portfolio insights. We are tackling one of the most complex and valuable challenges in finance. Our clients operate at the highest levels of global markets, managing billions in assets, yet they remain constrained by legacy systems that are slow, fragmented, and outdated. Cornspring is redefining Family Office services by applying state-of-the-art generative AI and Large Language Models to investment, accounting, and operational data. Our platform delivers faster insights, greater transparency, and entirely new ways of interacting with financial information.

Key responsibilities:

• You will be responsible for developing sophisticated data manipulation interfaces using TypeScript within the Microsoft Office Add-in ecosystem while also creating intuitive web applications where clients interact with their data using AI.
• You will design, build, and maintain high-performance Excel Add-ins using TypeScript and Office.js, tailored for internal Microsoft 365 deployment.
• You will develop and scale web interfaces for our AI solutions, data visualization, and reporting.
• You will work closely with our Backend team to ensure seamless integration with our cloud services while delivering exceptional user experiences in both Excel and our React-based web portal.
• You will contribute to architectural decisions, component libraries, and development best practices.
• You will support cross-team coordination around security, testing, deployment, and CI/CD pipelines.

Requirements:

• This role is perfect for someone who enjoys building robust user experiences that bridge traditional productivity tools (like Excel) with modern, responsive web apps; and who is excited by the opportunity to work with AI and financial data.
• This role requires strong expertise in modern UI development practices and professional frontend development experience with JavaScript, React, and TypeScript.
• You will need a deep understanding of data visualization, REST API integration, and responsive design principles.
• Experience handling authentication flows (e.g., OAuth), and managing async data interactions.
• Strong understanding of frontend performance optimization, state management, and cross-environment compatibility.
• Experience working in Agile teams, with a proactive and ownership-driven mindset.
• Experience building and deploying Office Add-ins, especially within Microsoft 365 for internal enterprise use, would be a strong advantage.

Benefits:

• Competitive salary and benefits.
• Hybrid working: 2 days per week at the office.
• An opportunity to work at the forefront of AI-driven finance, tackling genuinely complex and high-impact challenges.
• Hands-on exposure to advanced ML, LLM, and data technologies within real production systems.
• A collaborative, high-ownership start-up environment offering exceptional learning opportunities.
• The chance to help shape the future of Family Office and Asset Management technology.