We are seeking a highly skilled and experienced Senior PHP Developer to take on a critical role in maintaining, analyzing, and modernizing our established backend systems. This position offers a unique challenge to dive deep into an existing platform to ensure its stability while strategically planning and executing its technological evolution. You will be a key player in solving current business problems and shaping the future technical direction of our products.This position is responsible for:Take lead responsibility for understanding the current system architecture and source code developing with an old PHP framework.Analyze, debug, and resolve complex issues within the existing PHP codebase to ensure business continuity.Lead the analysis and propose viable, data-driven solutions for modernizing the platform, recommending new frameworks/technologies, architectural patterns.Design, develop, and maintain robust, scalable, and secure backend services, APIs, and business logic.Integrate with various payment gateways and processors, including ACH, credit/debit cards processing, and digital wallets like Google Pay/Apple Pay.Collaborate with product managers and clients to refine requirements and translate business needs into technical solutions.Implementing with high-quality, clean source code, comprehensive unit tests, managing code through version control, and participating in peer code reviews.Create and maintain clear technical documentation for the existing system and future enhancements.Mentoring skills, providing technical guidance/design is a plus.Manage all development stages from initial specification and design through to integration, release, and ongoing maintenance. Follow tightly the Agile methodology.