Senior Java Backend Engineer: Scalable, AI-Driven APIs

Once For All - Nalanda; Madrid; Presencial; EUR 50.000 - 60.000; Jornada completa

Ventajas ofrecidas por este puesto de trabajo

Flexible working time

Intensive summer period

Flexible benefits

Growth opportunities

Descripción de la vacante

Nalanda, part of Once For All, is seeking a Sr Java Backend Engineer to design and evolve our backend architecture, ensuring systems are scalable, maintainable, and robust. You will join a product engineering team that employs modern development practices, AI-powered tooling, and a fast-evolving engineering culture.

In this role, you’ll own complex backend domains, drive technical initiatives, and mentor other engineers while improving performance, reliability, and operational excellence across

Formación

• Solid experience with Java and Spring Boot, including Spring Data and Spring Web.
• Strong grasp of backend architecture and distributed systems.
• Experience with SQL databases (PostgreSQL preferred).
• Experience designing and consuming REST APIs with good error handling and versioning.
• Unit and integration testing with JUnit.
• Knowledge of Git, CI/CD pipelines and Docker.
• Willingness to mentor teammates and raise technical quality.
• Strong communication and decision-making skills.

Responsabilidades

• Design, build and maintain backend services, APIs and core platform components using Java and Spring Boot.
• Own complex technical problems end to end — from design through to production.
• Lead the design of scalable solutions and contribute to architecture decisions across databases, caching, messaging and distributed systems.
• Optimise services for performance, scalability, security and fault tolerance.
• Set the bar for code quality, testing, observability and documentation.
• Mentor junior and semi-senior engineers through code reviews, design discussions and feedback.
• Keep production healthy: incident resolution, root-cause analysis, refactoring opportunities.
• Use AI-powered development tools to improve delivery speed and code quality.

Conocimientos

Java

Spring Boot

Mentoring

Communication

Problem solving

Design patterns

Herramientas

PostgreSQL

Docker

Git

CI/CD

Kafka

Descripción del empleo

Nalanda, part of Once For All, is seeking a Sr Java Backend Engineer to design and evolve our backend architecture, ensuring systems are scalable, maintainable, and robust. You will join a product engineering team that employs modern development practices, AI-powered tooling, and a fast-evolving engineering culture.

In this role, you’ll own complex backend domains, drive technical initiatives, and mentor other engineers while improving performance, reliability, and operational excellence across