Acid Tango is a digital product studio. We transform our clients ideas into digital products, with a focus on digital innovation and bringing disruptive ideas to life. In every project, we search for the perfect harmony between simplicity, aesthetics, and technology. Were currently looking for a Lead software developer with solid Java expertise to join us. Youll bring experience in complex architectures and large-scale data systems, and youll lead a team of talented developers building products that matter. What youll do * Inspire, motivate, and lead senior and junior developers, fostering a culture of technical excellence and continuous learning. * Work closely with our design team and clients to deliver beautiful, thoughtful, and effective products that have a real impact on their business. * Drive the technical evolution of our clients projects, from architectural decisions to day-to-day implementation. * Champion high-quality engineering practices: TDD, clean code, code reviews, pair programming, and continuous refactoring. * Define and evolve software architectures based on Domain-Driven Design (DDD) and Hexagonal Architecture principles, ensuring our codebases stay maintainable, testable, and aligned with business needs. * Prioritize and coordinate code improvement initiatives across the team. * Bring your ideas and knowledge to help us keep raising the bar. What were looking for * 5+ years of experience in software development with Java. * Strong command of the Spring Boot framework. * Passion for software craftsmanship and clean, maintainable code.



* Deep knowledge of object-oriented programming, algorithms, and software architecture. * Hands-on experience with Test-Driven Development (TDD) as a daily working practice. * Solid understanding of Domain-Driven Design (DDD): bounded contexts, aggregates, ubiquitous language, and strategic design. * Practical experience designing and building applications with Hexagonal Architecture (Ports & Adapters) or similar approaches such as Clean Architecture or Onion Architecture. * Significant back-end experience with Java, with a clear understanding of its strengths and trade-offs. * Experience designing and exposing APIs (REST and ideally event-driven). * Solid SQL skills and working knowledge of PostgreSQL, plus familiarity with non-relational databases such as Redis and MongoDB. * Confident with Git, Linux environments, and the command line. Nice to have * Experience with CQRS, Event Sourcing, or asynchronous messaging (Kafka, RabbitMQ). * Exposure to microservices and distributed systems. * Familiarity with CI/CD pipelines and observability tooling. What we offer * Competitive salary by level: Senior (35–45K), Architect (45–55K), Tech Lead (55–65K). * Performance-based bonus of up to 12% of your salary. * €1,000/year education budget to keep growing. * Adaptable working hours and the option to work from home. * €300 to improve your home setup. * Challenging projects with a focus on innovation. * A dynamic, diverse team that wants to leave a mark. * International clients with thousands of users. If you think youd be a good fit, wed love to talk. ;-)

📌 Lead Java Developer (Madrid)
🏢 Acid Tango
📍 Madrid