UI Engineer (Junior to Mid-Level)

Job description

Company Description

Craxel is at the forefront of innovation in data analytics and artificial intelligence. Our revolutionary Black Forest™ technology provides an advanced knowledge infrastructure that enables AI-driven decision-making at any scale with unmatched speed and efficiency. By consolidating vast, complex, and fragmented datasets into AI-ready knowledge graphs, Black Forest empowers organisations to gain instant, actionable insights. From national security to financial intelligence, Craxel delivers transformative solutions for data-driven decision-making.

Role Description

We are seeking a Frontend Developer for a full-time hybrid role based in Belfast, with flexibility for some remote work. In this role, you will build and maintain the UI to our Black Forest™ data platform, you will also be responsible for the design and implementation of user interfaces for web applications, ensuring a seamless user experience. Day-to-day responsibilities include developing responsive web designs, collaborating with back-end developers to integrate APIs, and enhancing application performance. You will contribute to building scalable and innovative web solutions while working within a collaborative and fast-paced environment.

What You Will Work On

• REST API integration against BFKI query, config, and data endpoints
• Data exploration UI: charts, geo maps, time-series, tabular query results
• Complex form design and validation: nested config forms, credential inputs
• Async operation handling: service start-up feedback, connection testing, error states
• Unit and component testing
• Evolving the UI as BFKI APIs and capabilities expand

Must Have

2+ Years experience in a relevant role

Languages and Frameworks

• JavaScript/TypeScript
• HTML
• CSS

API Integration

• Experience with REST
• Understanding of query construction and result rendering from API responses

UI Patterns

• Complex form design and validation
• Role-aware UI patterns (permission-based rendering, route guards)
• Async operation handling and error state management

Data Vocabulary

• Familiarity with common visualization types: geo maps, time series, pie/bar/line charts, tabular data
• Ability to translate customer data requirements into appropriate frontend implementations

General

Git, GitHub Actions

Agile, Jira

Good to Know

• Modern Framework Experience
• React, Angular
• Modern Library Experience
• D3.js, Chart.js
• Modern UI Design Patterns
• WebSocket experience
• UX/CX design (e.g. Figma)
• OpenTelemetry
• Testing Framework Experience
• Unit: Jest
• E2E:Selenium, Playwright, Cypress
• Experience designing for WCAG compliance
• AWS or GCP

Bonus Points

Public GitHub with meaningful frontend contributions

Technical blog posts, conference talks, or published writing on data visualization or frontend architecture

What we offer

• A competitive salary and bonus plan
• Salary ranging from £40-50k depending on experience
• 25 days holidays plus 9 UK public holidays
• Private medical insurance including family cover, Dental and Optical
• 5% employer-matched pension to invest in your future
• Death in service cover and income protection
• Personal and business travel insurance
• A dedicated training and development allowance
• A health and well-being allowance to support life inside and outside of work
• Hybrid working, with flexibility

Extra information

Status

Open

Education Level

Secondary School

Location

Belfast

Type of Contract

Full-time jobs

Published at

20-05-2026

Full UK/EU driving license preferred

No

Car Preferred

No

Must be eligible to work in the EU

No

Cover Letter Required

No

Languages

English