Senior IT Developer (React.js)

b2bnetwork; Warszawa; On-site; PLN 120,000 - 180,000; Full time

Job summary

b2bnetwork is seeking a Frontend Developer to join the Sunray team working on the EFM UI application (Investment Fund Orders' processing administration UI). You will contribute to redesigns, implement new business requirements and support upcoming releases.

You will collaborate with Backend Developers, BAs, Test Engineers and users to clarify requirements, fix issues, and ensure high-quality delivery in an Agile environment. January–February 2027 continuity coverage is required.

Qualifications

• React.js (v18 or higher)
• React Query
• Typescript
• React Testing Library
• Material UI
• Tailwind
• React Form
• Hook oriented programming
• Good communication skills

Responsibilities

• Contributing to ongoing development of the redesigned (new technologies!) new EFM UI and implementation of new business requirements.
• Supporting preparation, stabilization and production rollout of upcoming EFM UI releases.
• Providing application support, troubleshooting and bug fixing for existing and newly delivered functionality.
• Taking over day-to-day EFM UI support responsibilities during January and February 2027 to ensure continuity while the current Frontend Developer is unavailable.
• Improving and maintaining EFM UI code quality, including remediation of identified vulnerabilities and framework dependencies.
• Collaborating closely with Backend Developers, Business Analysts, Test Engineers and EFM users to clarify requirements, investigate issues and deliver solutions.
• Participating in Agile team activities, including backlog refinement, sprint planning, reviews and production support activities.

Skills

React.js

React Query

Typescript

React Testing Library

Material UI

Tailwind

React Form

Hook oriented programming

Good communication skills

Tools

Jenkins

Job description

The consultant will join the Sunray team and work together with the current Frontend Developer on the development, maintenance and support of the EFM UI application (Investment Fund Orders' processing administration UI).

Key responsibilities include:

• Contributing to ongoing development of the redesigned (new technologies!) new EFM UI and implementation of new business requirements.
• Supporting preparation, stabilization and production rollout of upcoming EFM UI releases.
• Providing application support, troubleshooting and bug fixing for existing and newly delivered functionality.
• Taking over day-to-day EFM UI support responsibilities during January and February 2027 to ensure continuity while the current Frontend Developer is unavailable.
• Improving and maintaining EFM UI code quality, including remediation of identified vulnerabilities and framework dependencies.
• Collaborating closely with Backend Developers, Business Analysts, Test Engineers and EFM users to clarify requirements, investigate issues and deliver solutions.
• Participating in Agile team activities, including backlog refinement, sprint planning, reviews and production support activities.

Must-have knowledge and experience

• - React.js (v18 or higher)
• - React Query
• - Typescript
• - React Testing Library
• - Material UI
• - Tailwind
• - React Form
• - Hook oriented programming
• - Good communication skills

Nice-to-have knowledge and experience

• Basics of Java and SpringBoot
• Other tanstack libraries
• Jenkins