Website Functionality Upgrades Needed

I have an existing site that runs well visually but now needs solid functionality work. The priorities are threefold:

• Integrate a secure user-authentication system so visitors can register, log in, and manage their own profiles without hiccups.
• Hunt down and repair the bugs that have crept into the current codebase, particularly those affecting form submissions and occasional 500 errors.
• Optimise performance—page-load speed, database queries, and any front-end bottlenecks—so we hit faster Lighthouse scores and lower server strain.

You can review the current stack with me (PHP/Laravel on the back end, a modest MySQL database, and vanilla JS on the front). I will grant repo access and staging credentials for testing.

Deliverables are:
1. Fully implemented, tested user authentication (registration, login, password reset, session management).
2. A concise changelog of all bugs fixed, including the root cause and solution for each.
3. Performance report showing at least a 20 % improvement in key metrics, plus the code/config changes that achieved it.

Please outline your approach, expected timeline, and any similar projects you’ve handled. I’m ready to start as soon as we agree on the plan.