Senior Software Engineer in London

Elliptic is looking for a senior software engineer to join our Data Fabric team, building tools and APIs to connect raw and enriched data with user-facing applications. This is a great opportunity to work closely with both world-class data engineers and product managers to deliver a unified, reusable, and query-ready platform to empower customers to explore, integrate, and build data products with confidence and adaptability. You'll play a key role in connecting backend data with frontend experiences and help shape new initiatives across our product landscape.

The impact you will have: You'll join a growing cross-functional team building simple and powerful applications to deliver Elliptic's digital asset intelligence. The Data Fabric team focuses on standardising data and providing self-serve access, transforming raw information into usable data services through well-designed APIs and intuitive frontend components.

In this role, you'll own the application development across the full stack from designing APIs, contributing to frontend features, and guiding how data is represented and queried efficiently. You'll partner closely with data engineers and other product teams to support a shared vision for data access, standardisation and performance.

What you will do:

• Design and develop APIs that standardise access to complex internal datasets (ideally using NestJS, TypeScript, and Kong)
• Bring thoughtful design practices to API development including versioning, authentication, and security
• Work on the frontend stack (React/Redux, TypeScript) to surface and display data in clear, user-friendly and intuitive ways
• Work closely with data engineers to discuss backend data requirements and optimise queries to keep costs down
• Contribute to data visualisation strategy through intuitive dashboards and tools for exploring complex datasets
• Take full ownership of your code from development through production, help enhance our processes, and foster a collaborative, problem-solving engineering culture
• Collaborate with other application engineers across chapters and teams

You will be a great fit here if you:

• Care deeply about code quality and write clean, maintainable and tested code
• Enjoy solving problems through discussion and collaboration
• Have strong opinions on effective API design and data structure, but are open to evolving them
• Are curious about how users use data and how to make it more actionable and accessible
• Stay pragmatic by recognising when to aim for perfection and when 'good enough' helps us learn faster
• Take full ownership of your work through the entire lifecycle of software development
• Are comfortable switching between backend and frontend development, and enjoy collaborating with data engineers

Our ideal candidate has:

• Strong experience with modern JavaScript and TypeScript in both backend (Node.js/NestJS) and frontend (React/Redux)
• A solid understanding of API design principles including auth, scalability and security
• Comfort working with varied data sources like CSVs, JSON, lists or similar formats
• Worked with databases and writing complex queries
• Prior exposure to working closely with data engineers or building on top of systems like Databricks, Kinesis or large-scale ETL pipelines
• Experience working in AWS environments using services like DynamoDB, Lambda

• Interest or experience in natural language to SQL functionality or experimentations with AI-assisted querying
• Experience with Terraform or other IaC tools
• Familiarity with monitoring tools like DataDog and general observability best practices
• Knowledge of data visualisation principles or libraries
• Interest in cryptocurrency and blockchain technology

How we work: Hybrid working and the option to work from almost anywhere for up to 90 days per year. £500 Remote working budget to set up your home office space.

Learning & Development: $1,000 Learning & Development budget to use on anything (agreed with your manager) that contributes to your growth and development.

Vacation/ Leave: Holidays: 25 days of annual leave + bank holidays. An extra day for your birthday. Enhanced parental leave: we provide eligible employees, regardless of gender or whether they become a parent by birth or adoption, 16 weeks fully-paid leave.

Benefits: Private Health Insurance - we use Vitality! Full access to Spill Mental Health Support. Life Assurance: we hope you will never need this - but our cover is for 4 times your salary to your beneficiaries. £100 Crypto for you! Cycle to Work Scheme.