Senior JavaScript Engineer | DataGrid & Charting Libraries | London

Frontend Systems Engineer – DataGrid & Visualisation Libraries | London (Hybrid)£150,000 – £200,000 + package
I’m hiring for a developer tools company building widely adopted JavaScript components used in data-intensive applications across global enterprises, financial institutions, and technology companies.
This is core engineering work, focused on performance, scalability, and building systems that operate at the limits of the browser.
Developing and optimising a high-performance DataGrid and charting library used globally
Solving complex problems around rendering, large datasets, and real-time updates
Working across data structures, algorithms, and performance-critical code paths
Building features end-to-end — from design through to release
Strong JavaScript and TypeScript fundamentals (framework-agnostic mindset)
Experience with a statically typed language (C++, C#, Java, Python, etc.)
Deep understanding of algorithms, data structures, and software...