C language full expert that understands existing long code and helps to modify the required parts.

I am seeking assistance for a large, highly complex C language codebase. I am somewhat familiar with the codebase, but I need help with debugging and optimizing it. This project will require an experienced and knowledgeable C language expert who can help with understanding existing code and identifying areas for modification and improvement. If you think you have the skills and knowledge to get this job done, please reach out and let me know. I look forward to working with you soon!