Senior AI UI Engineer: Interactive Visualization Lead

Mastercard; Greystones; On-site; EUR 90,000 - 120,000; Full time

Job summary

Mastercard is seeking a Senior UI Developer to join an AI product team building frontend applications for internal tooling and external self-service tools. You will design and implement interactive visualizations for embeddings and model outputs, and integrate with the platform’s API layer.

You will own frontend architecture, collaborate with AI engineers and data scientists, and ensure scalable, maintainable code with strong UI/UX focus.

Qualifications

• Strong, production-level frontend development experience in React, and/or Python-based data-app frameworks (Streamlit or Dash).
• Component architecture, state management, and building applications meant to be maintained and extended over time, not one-off prototypes.
• Experience integrating frontend applications against REST APIs. Including handling authentication, asynchronous job patterns (submit, poll/callback, retrieve), and designing around API versioning.
• Familiarity with visualization libraries capable of advanced/interactive rendering (e.g., D3.js, deck.gl, Plotly, or similar).
• Familiarity with Databricks Apps as a hosting/deployment model, including its constraints and how it serves React, Streamlit, and Dash applications specifically. Direct Databricks experience is a strong plus.
• Advanced data visualization experience, including interactive/exploratory tooling. Not just static charts, but genuinely interactive interfaces: filtering, drill-down, dynamic re-rendering, and ideally experience visualizing high-dimensional or embedding-style data.
• Comfortable designing for mixed technical audiences. From AI engineers who want dense, fast access to detail, to end users who need simplicity and guardrails.
• Fluency reading/writing SQL or querying a governed data platform (e.g., Unity Catalog).
• Strong UI/UX instincts. Able to make reasonable design decisions independently rather than needing every interaction pattern specified, while knowing when to loop in design/product input.
• Solid testing and code quality practices for frontend code. Component/unit testing, and comfort working within CI/CD pipelines the rest of the team maintains.
• Clear communicator, able to work directly with backend, data, and AI engineering roles to understand what an interface actually needs to expose.
• Comfortable operating in a fast-moving, evolving environment.

Responsibilities

• Design and build advanced, interactive visualization tooling for embeddings and model outputs.
• Design and build self-service applications for end users, integrating against the platform's API layer.
• Build prototypes for future product versions and executive level demos.
• Own frontend code quality and maintainability, including testing and documentation.

Skills

React

Streamlit

Dash

Python data apps

Component architecture

State management

REST APIs

D3.js

deck.gl

Plotly

Databricks Apps

Advanced visualization

UI/UX

Testing

Communication

SQL

Adaptability

Tools

Databricks Apps

React

Streamlit

Dash

D3.js

Plotly

Job description

Mastercard is seeking a Senior UI Developer to join an AI product team building frontend applications for internal tooling and external self-service tools. You will design and implement interactive visualizations for embeddings and model outputs, and integrate with the platform’s API layer.

You will own frontend architecture, collaborate with AI engineers and data scientists, and ensure scalable, maintainable code with strong UI/UX focus.