(Senior) Backend Developer (m/f/d) with Fullstack affinity in Bonn

Gulp Ag; Bonn; Hybrid; EUR 70,000 - 110,000; Full time

Job summary

Gulp AG in Bonn seeks a (Senior) Backend Developer with full-stack expertise. The role focuses ~80% on backend (Java, Spring Boot, PostgreSQL, security) and contributes to UI with React.

You will help evolve a central management platform for network-wide security and device management, and work with the UX/UI team on modern interfaces. Requirements include a CS degree or similar, several years in professional software development, agile experience, and strong knowledge of TypeScript, JavaScript,

Qualifications

• Completed studies in computer science / a comparable field or vocational training.
• Several years of solid experience in professional software development.
• Experience in agile teams (Scrum framework).
• Knowledge of TypeScript, JavaScript and Java.
• Familiarity with React, Spring Boot and REST APIs.
• Experience with Git, GitLab, Jira, Confluence, Linux environments and PostgreSQL.
• Knowledge in Identity & Access Management (Keycloak).
• Understanding of network protocols and cryptographic concepts.
• Very good German and good English skills, both spoken and written.

Responsibilities

• Contribute to the further development of a central management platform for network-wide security and device management.
• Develop modern user interfaces in close collaboration with the UX/UI team using React.
• Design and implement backend services, including data migration from legacy systems.
• Software development and integration on Linux-based systems.
• Design and implement automated software tests.

Skills

Software development experience

Agile / Scrum

TypeScript

JavaScript

Java

React

Spring Boot

REST APIs

Keycloak

Networking basics

German language

English language

Education

Computer science degree or comparable field

Tools

Git

GitLab

Jira

Confluence

Linux environments

PostgreSQL

Job description

On behalf of our client, we are seeking a (Senior) Backend Developer (m/f/d) with full-stack expertise for their Bonn location (including a flexible mobile office model). Our client is a leading solutions provider in the field of highly secure IT infrastructure and cryptography. In this role, your focus will be approximately 80% on backend development (Java, Spring Boot, PostgreSQL, security & network architecture), complemented by contributing to the user interface design using React. Your responsibilities will include: contributing to the further development of a central management platform for network-wide security and device management (client-server architecture based on React and Spring Boot); developing modern user interfaces in close collaboration with the UX/UI team; designing and implementing backend services, including data migration from legacy systems; software development and integration on Linux-based systems; and designing and implementing automated software tests.

• Completed studies in computer science / a comparable field or comparable vocational training

• Several years of solid experience in professional software development

• Practical experience in agile teams (e.g., Scrum framework)

• Excellent knowledge of TypeScript, JavaScript and Java

• Secure use of frameworks and standards such as React, Spring Boot and REST APIs

• Familiarity with development and collaboration tools ( e.g., Git, GitLab, Jira, Confluence, Linux environments, relational databases such as PostgreSQL )

• Knowledge in the field of Identity & Access Management (e.g. Keycloak)

• Basic understanding of network protocols and technologies (VPN, TCP/IP, routing) as well as cryptographic concepts (asymmetric encryption, certificate management)

• Very good German and good English skills, both spoken and written.