Fixes in CMS in PHP7 laravel MYSQL & Jquery

We have CMS/CRM, API for the site, integration with external services, heavy filtering sql queries.

Our current stack:
PHP 7
LARAVEL
MYSQL
JQUERY

You need a person who has experience in writing complex business logic on Laravel, taking into account Best Practices and with the appropriate application of design patterns. With a deep understanding of SQL in general (aggregation, indexing, optimization of the structure of tables and queries) and Eloquent in particular.

First, there is a small task for a pack of minor corrections.

Please send a sample of your code and similar projects when you respond.