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SquareDev

Backend Engineer (Senior)

SquareDev
Luxembourg · Full-time · Mid-Senior
Why are you looking for a job?

If your answer ticks all the boxes, this could be the start of a great collaboration.

  • You have a curious mind - You won't understand what we're talking about if you don't.
  • You want to learn more around technology - You won't survive if you don't
  • You want to make the world a bit better - We don't like you if you don't

We happen to be just like that as well. We like hacking things here and there (you included) and create scalable solutions that bring value to the world.

Squaredev? 🐿️

We use state-of-the-art technology to build solutions for our own customers and for the customers of our partners. We make sure we stay best-in-class by participating in research projects across Europe, collaborating with top universities and enterprises on AI, Data, and Cloud.

Role Overview

We are looking for an experienced Backend Engineer who will design, develop, maintain, test, and deploy robust and scalable web portals, applications, reusable components, and backend services using Java and the Spring ecosystem. You will collaborate closely with team leads, tech leads, business analysts, developers, and QA engineers to fully understand business and technical requirements, ensuring alignment, consistency, and high-quality implementation across the entire development lifecycle.

You will also play an active role in deploying, monitoring, and supporting applications in both on-premises and cloud-based containerized environments, contributing to architectural decisions and continuously improving system performance, scalability, and reliability.

Requirements

To excel in this role, you'll need:

  • Strong expertise in Java (version 17, preferably 21 or higher), with a deep understanding of object-oriented programming principles, clean code practices, performance optimization, and modern Java features. You should be comfortable building enterprise-grade applications with high reliability and maintainability standards.
  • Solid hands-on experience with Spring Framework 6.x and Spring Boot 3.x (or higher), including dependency injection, configuration management, REST controller development, validation, security, and production-ready application setup. A strong understanding of the Spring ecosystem and its best practices is essential.
  • Proven experience with JPA and Hibernate, including entity mapping, transaction management, performance tuning, and complex query handling. You should understand persistence context behavior and how to design efficient data access layers.
  • Experience designing and consuming web services, including RESTful APIs and SOAP services. Familiarity with asynchronous communication patterns and event-driven architectures, particularly using technologies such as Kafka, is highly important for building scalable distributed systems.
  • Strong testing skills using JUnit or TestNG, along with mocking frameworks such as Mockito (or similar). You should be able to design comprehensive unit and integration tests, ensuring high code coverage, reliability, and maintainability.
  • Good understanding of DevOps practices and tooling, including Maven for dependency management and build automation, Git for version control, and CI/CD pipelines (preferably Azure DevOps). Experience working with container technologies such as Docker and deploying applications to cloud platforms (preferably Azure) is highly valuable.
  • Experience implementing authentication and authorization mechanisms, particularly using modern standards such as OIDC and OAuth. You should understand secure API design and how to integrate identity providers within enterprise systems.
  • Ability to deploy and monitor applications in containerized environments, supporting both on-premises and cloud infrastructures, ensuring performance, observability, and operational stability

Would be considered a strong plus:

  • Experience with integration technologies and microservices architectures, preferably using Apache Camel, while knowledge of Spring Integration is also highly appreciated. Understanding enterprise integration patterns and service orchestration is a significant advantage.
  • Exposure to full-stack development with a JavaScript framework, preferably React, allowing better collaboration across frontend and backend layers.
  • Experience working with process/workflow engines such as Temporal or similar platforms, enabling orchestration of complex business processes and long-running workflows

Key Skills

Ranked by relevance

cloud java devops configuration management microservices restful apis spring boot javascript docker apache testng react kafka maven oauth excel junit cicd git
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Country Guide

Luxembourg

High-value international enterprise and fintech hub

Posted
Mar 03, 2026
Type
Full-time
Level
Mid-Senior
Location
Luxembourg
Company
SquareDev

Industries

IT Services IT Consulting

Categories

Other

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