Senior PHP Full Stack Developer for Existing Web Application

We are looking for a senior full stack developer to work on an established web application that is already in production. The immediate work includes reviewing the existing architecture, resolving backend issues, improving current features, and developing several new application workflows. This is not a greenfield build, so you should be comfortable joining an existing project, understanding unfamiliar code, and making changes without disrupting live functionality. Most of the backend is PHP-based, with Laravel and Symfony used across different parts of the application. You should have strong experience building REST APIs, working with relational databases, handling authentication and permissions, and integrating external services. Typical tasks may include: Developing and extending PHP/Laravel application features Maintaining Symfony and custom PHP components Building and updating REST API endpoints Integrating third-party APIs and external services Troubleshooting production bugs and application errors Improving MySQL queries and backend performance Working with authentication, roles, sessions, and permissions Connecting frontend interfaces with backend APIs Reviewing existing code and refactoring where appropriate Using Git for version control and collaborative development The frontend includes JavaScript, React, HTML5, CSS3, Bootstrap, and some legacy jQuery. You do not need to be primarily a frontend specialist, but you should be comfortable tracing issues across the full application stack. Experience with Node.js, Python, WordPress, server-side integrations, or maintaining older PHP applications is helpful but not required. We are looking for someone who can work independently, communicate technical issues clearly, and make practical decisions inside an existing production system. Please include a short description of a PHP/Laravel or Symfony project where you inherited an existing codebase and had to troubleshoot or extend it.