Senior Backend Engineer role with PHP expertise, leadership on complex, scalable systems. Responsibilities include architecting systems, building core backend services, performance optimization, security/compliance, mentoring, code reviews, cross-functional collaboration, database management, testing strategies, incident management, and staying current with industry trends. Requirements: Bachelor's degree in CS/Software Eng or equivalent, 5+ years backend experience with leadership on complex projects, expert PHP, knowledge of Python/Go/Node.js a plus, scalable architecture, SQL/NoSQL DBs, robust API design (REST/GraphQL), cloud services (AWS/GCP), Docker, Kubernetes, security, Git, CI/CD, automated testing, DevOps. Compensation: USD salary, fully remote work with flexible hours, medical insurance, fast career growth.