Senior Java/PHP Engineer

About the role

As a Senior Backend Engineer, you will build and maintain the server-side services behind business-critical applications for our Client, a European public sector organization. You will own the business logic, APIs, and data access you deliver, along with their correctness, security, and observability in production — working with Java or PHP back-end stacks over relational and document databases, deployed in containerized environments.

Responsibilities

• Design, develop, and maintain back-end services and business logic using Java, PHP, and frameworks such as Spring Boot, Hibernate, or Node.js
• Take technical ownership of the services you deliver, including their correctness, error handling, performance, and security in production
• Work with fellow engineers, front-end developers, and stakeholders to turn requirements into working services, taking part in multi-lingual discussions and supporting colleagues through code review
• Design, build, secure, and document RESTful APIs and web services, including OpenAPI/Swagger documentation and authentication and authorization mechanisms
• Design and optimize relational and document data structures, including writing complex SQL queries and choosing between consistency and performance trade-offs
• Set up and use application performance monitoring and observability tooling to analyze metrics, logs, and traces, and act on what they show
• Analyze complex back-end issues, identify root causes, and design effective solutions
• Build and deploy applications using containerization and orchestration technologies, working within the established Git workflows and keeping documentation current

Requirements

• A university degree at master's level (or 5 years of higher education) with a minimum of 10 years of IT professional experience. All fields of study are accepted, including degrees not related to information technology
• Proficiency in back-end languages (Java, PHP) and experience with frameworks such as Spring Boot, Hibernate, and Node.js, with a strong understanding of the web development cycle and of programming techniques and tools
• Proficiency in working with relational databases (e.g. PostgreSQL, Oracle, MySQL), including writing complex SQL queries and understanding database design
• Knowledge of NoSQL document stores (MongoDB, CouchDB, CosmosDB) and understanding of the consistency and performance trade-offs involved
• Experience designing, building, and securing RESTful APIs and web services, including OpenAPI/Swagger documentation, and understanding of authentication and authorization protocols and standards (e.g. OAuth 2.0, OpenID Connect, JWT)
• Experience with APM tools (Dynatrace, Splunk, Elastic APM) and knowledge of OpenTelemetry for metrics, logs, and traces
• Experience with Git workflows (GitFlow, trunk-based), an understanding of legacy systems using SVN, and knowledge of containerization and orchestration technologies (e.g. Docker, Kubernetes) for developing and deploying applications
• Optional certification: AWS Certified Developer Associate, Microsoft Azure Developer Associate, CNCF Certified Kubernetes Application Developer (CKAD), or an equivalent certification
• Very good knowledge of English or French, both spoken and written, corresponding to Level B2 or higher (CEFR), with a talent for attention to detail in code correctness, error handling and documentation, excellent interpersonal and communication skills, the ability to integrate into an international and multicultural environment and take part in multilingual meetings, and to work both autonomously and as part of a team with a results-oriented mindset