Job Title: Senior Full-Stack Developer (Java, Spring Boot)

Location: Esch Belval

Employment Type: Full-time

Experience Level: Senior

About Us:

Payroll Engine is a Luxembourg-based entity of the international Securex Group, combining the agility of a tech company with the stability and expertise of a leading HR and payroll provider.

We develop a next-generation, cloud-native payroll platform and are looking for a Senior Full-Stack Developer ready to take ownership and build mission-critical systems in a dynamic environment.

Job Description:

We are searching for an experienced Senior Full-Stack Developer with deep expertise in Java, Spring Boot and MongoDB. This is not just a coding role — you will be a crucial part of our team, helping shape the architecture, technical decisions, and product vision. In a startup environment, your voice matters, and you'll work closely with our small, tight-knit team to build scalable, high-performance web applications. If you're excited about contributing to both the backend and frontend, enjoy tackling new challenges, and want to have a direct impact on the company’s growth, we’d love to talk!

Key Responsibilities:

• Full-Stack Development: Own the development and deployment of end-to-end web applications, from the frontend interface to the backend architecture, using Java, Spring Boot, React and MongoDB.
• Backend Development: Design and implement scalable, secure, and maintainable APIs and microservices with Spring Boot and Java, managing data efficiently with MongoDB.
• Frontend Development: Build modern, responsive, and interactive web interfaces using VueJS/React, focusing on delivering a seamless user experience.
• Startup Versatility: As part of a team of 6 people, you’ll need to be flexible and contribute to various areas — whether it's brainstorming new features, debugging critical issues, or improving development workflows.
• Product Ownership: Collaborate with the founder and the team to take ownership of key features and drive them from concept to delivery.
• Architecture & Design: Play a pivotal role in designing system architecture, making technical decisions, and ensuring code quality across the stack.
• Performance Optimization: Continuously improve application performance and scalability to handle growing user traffic.
• Team Collaboration: Work closely with the product team to align on business needs and technical solutions, contributing to the overall product strategy.
• Mentorship: As one of the senior developers, help guide and mentor more junior team members as the team grows.

Required Skills & Qualifications:

• 5+ years of experience as a Full-Stack Developer, ideally in a fast-paced startup or small team environment.
• Expertise in Java and Spring Boot, with hands-on experience building production-grade web applications.
• Strong experience with React (or Angular), building user-friendly interfaces.
• Solid knowledge of MongoDB or other NoSQL databases, with experience in database design and query optimization.
• Experience with RESTful APIs, microservices architecture, and server-side development.
• Ability to work independently and manage multiple responsibilities in a fast-paced environment.
• A proactive approach to problem-solving and the ability to quickly adapt to new challenges and technologies.
• Strong understanding of HTML5, CSS3, and JavaScript/ES6.
• Familiarity with version control (Git) and development workflows (CI/CD).
• Agility: Comfortable working in an Agile environment, with a willingness to adapt to changing needs and priorities.
• Startup Mentality: Excited to contribute ideas, iterate quickly, and take ownership of projects from start to finish.

Bonus Points For:

• Knowledge of cloud platforms (AWS) or containerization tools (Docker, Kubernetes).
• Interest in DevOps practices and infrastructure management.
• Experience working in small, cross-functional teams in a startup environment.

Why Join Us:

• Startup Culture: Be a part of a passionate, energetic team where your ideas and contributions will have a direct impact on the company’s growth and success.
• Ownership & Impact: You'll have the freedom to take ownership of projects and see them through from conception to deployment.
• Innovation: Work on exciting, cutting-edge projects where innovation is encouraged.
• Flexible Work Environment: We offer a flexible, dynamic work environment that fits your lifestyle, including the possibility of remote work.
• Growth Opportunities: As an early member of our team, you’ll have significant opportunities to grow with the company, both personally and professionally.
• Collaborative Team: Work directly with the founder and be part of shaping the future of the product and company.