About EntityX

EntityX is a high-growth, investment-funded business. We are a dedicated team of engineers and data scientists building the next generation of privacy-first audience intelligence.

EntityX's technology uses a range of in-house and 3rd party NLP and AI techniques to merge the curated knowledge of Wikipedia with billions of daily data points about consumer media consumption. This allows us to generate a deep understanding of consumers and culture (‘Cultural Intelligence’) and deliver digital ad targeting solutions that have zero dependency on personal data (‘Cultural Activation’).

Role Overview

We are looking for a Full-Stack Engineer to help us build out the EntityX platform. In a small, agile team of 10, we value engineers who can wear multiple hats and take full ownership of a feature's lifecycle. You will be responsible for the last mile of our product, translating billions of data points and complex NLP outputs into intuitive, high-performance interfaces. 

While we have some existing infrastructure in Streamlit, your role will be pivotal in transitioning our core user experience to a robust React architecture while maintaining and tweaking our internal reporting tools. You should be someone who thrives on building end-to-end—handling everything from complex state management in TypeScript to optimized SQL queries in BigQuery.

Key Responsibilities

• End-to-End Feature Development: Lead the development of new platform features using React, TypeScript, and FastAPI, ensuring a high-quality user experience from the UI to the database.

• Graph Visualisation: Build and optimize 2D and 3D data visualizations that allow users to explore complex knowledge graphs.

• API Design & Performance: Architect and optimize Python services and APIs to fetch data from BigQuery data marts, ensuring that complex data lookups remain responsive for the end user

• Internal Tooling & Prototyping: As a Python-forward team, we rely heavily on Streamlit for our internal research and R&D. You will support these existing tools while strategically graduating high-impact features into our React apps. You’ll also help the team move faster by providing the React-based custom components that supercharge our Python-based workflows.

• Schema-Driven Development: Leverage our monorepo and Pydantic-to-TS code generation to maintain strict type safety, ensuring that as our Python models evolve, the frontend stays perfectly in sync without manual overhead.

• Collaborative Engineering: Partner with our Data Platform Engineers to consume Data Marts. You will play a key role in defining the API contracts that allow our 'Cultural Intelligence' engine to scale to the frontend seamlessly.

• Testing & Quality: Maintain high standards through automated testing (Vitest/Jest) and active participation in technical peer reviews to ensure a scalable, clean codebase.Qualifications

Requirements

• Strong Full-Stack Experience: Proven experience building and scaling web applications using React and Python.

• Frontend Expertise: Deep knowledge of TypeScript, modern React patterns, and bundling tools like Vite or Rollup.

• Python Proficiency: Proficient in Python (FastAPI/Pydantic). You should be comfortable writing optimized SQL to fetch data, but you won't be responsible for building or maintaining the underlying data pipelines.

• Data Savvy: Ability to interpret data and bridge the gap between the complex raw data and an intuitive UI.

• Testing Mindset: Experience writing unit and integration tests using Jest, Vitest, or similar frameworks.

• Pragmatic Approach: You prefer simple, well-architected code over over-engineered solutions and are driven to see your work solve actual problems.

Bonus Points

• High-Performance Visuals: Experience with WebGL, Canvas, or Three.js. You know how to render and manipulate large-scale knowledge graphs (thousands of nodes/edges) while maintaining browser speed and stability.

• Tooling: Familiarity with Nx monorepos or managing complex build pipelines.

• Streamlit: Experience wrapping React components for use within Streamlit applications.

• Ad Tech & Privacy: Any exposure to the digital advertising ecosystem or an interest in the "privacy-first" movement (e.g., working without cookies/PII).

What We Offer

• Opportunity to work on cutting-edge AI and data analysis technology

• A collaborative, authentic work environment that values talent and self-motivation

• Opportunity to make meaningful contributions and advance as the company grows

• 28 days holiday per annum, including Bank Holidays

• Birthday leave - an additional paid day off for your birthday

• Bonus holiday time - office closure between Christmas and New Year, when operationally possible

• Share option (based on length of service)

• Remote-first with occasional in-person collaboration in London (no fixed hybrid schedule)

• Continuous learning and professional development opportunities

At EntityX, we believe in the power of diverse perspectives and are committed to creating an inclusive environment for all employees. We encourage applications from candidates of all backgrounds.