Summary: Mad Collective is seeking a talented and passionate Backend Developer to maintain, evolve, and modernize their core billing platform, focusing on performance, reliability, and scalability. Highlights: 1. Opportunity to build deep expertise in the billing domain 2. Work in a nice and safe environment with a team-first culture 3. Leverage AI to support development and accelerate iteration Mad Collective is a digital entertainment company founded in Rochester (NY) in the early 2000s, with offices in Barcelona since 2007\. We're a dynamic and diverse team, driven by innovation and new opportunities. Our team includes technologists, marketers, business operators, video producers, and VR experts, with members representing a wide range of nationalities and backgrounds. We are looking for a talented and passionate Backend Developer to join our Billing Engineering team! **What will you do?** Maintain, evolve, and modernize our core billing platform; deliver new capabilities across the system; troubleshoot high\-impact production issues at scale; and drive improvements in performance, reliability, and scalability. We follow solid engineering practices and a culture of continuous improvement while working on a large legacy PHP monolith that supports a key system in our business. Our infrastructure runs on Kubernetes, and the team combines ownership of a business\-critical platform with ongoing modernization efforts. This role offers the opportunity to build deep expertise in the billing domain, working on complex challenges with direct impact. We also leverage AI to support development, accelerate iteration, and continuously improve how we work. Just as important, we like to work in a nice and safe environment, where everyone is accountable, friendly, and always willing to help. We work as a team and encourage opinions. We operate as a hybrid\-remote company, giving everyone the flexibility to work from home two days per week. This balance supports both collaboration and individual productivity. **Main responsibilities** * Own the maintenance, modernization, and ongoing evolution of our core Billing platform and its components. * Investigate, diagnose, and resolve high\-impact production issues in a high\-traffic environment. * Promote knowledge sharing across the team around best practices, technical approaches, and new technologies. * Help drive improvements in performance, scalability, and reliability across the platform. * Contribute throughout the full software development lifecycle, from design and implementation to deployment and support. * Produce clear technical documentation for both existing systems and new components. **Requirements** * Strong foundation in software design, including OOP patterns, Clean Code, and SOLID principles. * Experience maintaining, evolving, and improving complex legacy systems. * Strong professional experience with PHP. * Excellent analytical, debugging, troubleshooting, and problem\-solving skills. * Experience leveraging AI tools such as Cursor, Claude Code, and coding agents to support software development and improve productivity. * Hands\-on experience with Docker. * Hands\-on experience with AWS services. * Strong experience writing efficient, high\-performance SQL queries in MySQL. * Business\-level English, written and spoken. * Strong collaboration and communication skills, with a team\-first attitude. **Extra points** * Experience working in high\-traffic production environments. * Experience with Kubernetes and Helm. * Experience working with queue\-based or asynchronous systems. * Experience with non\-relational databases. * Experience with CI/CD pipelines and practices. * Experience with observability and monitoring tools such as Datadog and Grafana. **Hiring process** * First interview with our People team, to get to know your profile and explain the company and the role. * Second interview with the Hiring Manager and the Tech Lead, to review your technical skills and provide more information about the team and position. * Technical test, do it when you can, no time constraints. Optionally you can show us one of your projects. * Third interview with the Tech Lead and a Developer from the team to review the technical test and ask follow\-up questions * Offer **Benefits** * Private Health and Dental Insurance plan * Subsidized gym memberships and fitness classes * Monthly internet allowance * Working from home setup allowance * Sponsored training and development * Top\-notch Apple equipment * Remote policy and flexible working hours * Flexible Bank Holidays — design your own working calendar with a lengthy consecutive vacation policy * Day off for your birthday * Hybrid remote model office Sounds good? Apply now for this position! Please note: All applications must be submitted in English.