Senior Backend Engineer

About

As a Back End Engineer you are responsible for designing, developing, and maintaining the server-side components, APIs, and data architecture of our software applications. This role requires deep expertise in back-end technologies and the ability to build robust, scalable systems while collaborating effectively within an agile team environment. This position involves working closely with Engineering Managers, Product Managers, Front End Engineers, and other team members to implement features, improve system architecture, and ensure high-quality deliverables that meet both technical and business requirements.

The Back End Engineer will be part of a cross‑functional squad and will contribute to technical decisions while maintaining high standards of code quality, performance, and security.

Learn more about our Tech Team through our Medium.

Key Responsibilities

Technical Development

• Design, develop, and maintain scalable back‑end services and APIs
• Build and optimize database schemas and data models
• Write clean, maintainable, and well‑tested code following team standards and best practices
• Participate in code reviews and provide constructive feedback to team members
• Debug production issues and implement robust solutions
• Contribute to technical documentation and architecture decisions
• Design and implement RESTful APIs and GraphQL endpoints
• Optimize application performance, database queries, and system scalability
• Implement caching strategies and asynchronous processing systems
• Participate in agile ceremonies and technical planning sessions

Collaboration and Innovation

• Actively participate within an autonomous mission team (PM, Designer, Engineering manager, Front End Engineers) to clarify priorities and user needs
• Contribute to technical discussions and architecture decisions
• Collaborate with front‑end engineers to define API contracts and data structures
• Participate in squad rituals and team meetings
• Handle support requests and bug fixes within agreed SLAs

Quality & Best Practices

• Write unit tests and integration tests following TDD principles
• Collaborate with QA team to ensure comprehensive test coverage
• Participate in pair programming sessions with team members
• Monitor application performance, scalability, and implement improvements
• Follow security best practices and address vulnerabilities proactively
• Contribute to continuous integration and deployment processes
• Implement logging, monitoring, and alerting systems
• Ensure data integrity and implement backup strategies

Benefits @ Welcome to the Jungle

• Salary range: €55K – €70K
• 4‑day work week after your first month
• 5 weeks of paid vacation
• Flexible remote work
• 75% of Navigo Pass or €20 monthly sustainable allowance
• Alan health insurance – 66% covered for you and your children, 40% for your partner
• Meal vouchers – Swile Card – €9 per working day, 50% funded by Welcome