As someone who has been working with PHP and MySQL for over 12 years, I'm confident that I'll be able to solve the issue you're facing with Firebase notifications. My knowledge and experience in Odoo, AWS and ROR gives me a strong foundation in understanding complex backend systems like the one you mentioned.
I've worked on several ready-made applications, including those using PHP and MySQL, which required integrating Firebase's API for the notification feature. Drawing from this experience, I'm well-versed in troubleshooting, debugging and resolving any compatibility and functionality issues.
In conclusion, my expertise in PHP, MySQL along with my ability to solve complex problems makes me an ideal fit for your project. I understand how important proper functioning of notifications is to user experience and I guarantee that after working with me, your application will be firing all notifications without a hitch. I look forward to hearing more about your project and how I can assist you further.