Continue the development of the site-catalog on Laravel. Take on Support

We are developing a website-catalog on Laravel https://new.ruzhbi.ru/. The project is not quite typical, relatively complex. The programmer implemented ~2/3, but the most difficult part remained, and he did not take it out.Requires an executor with good experience in Laravel-development, responsible, able to understand someone elses code. The basic requirements for the finished product are compliance with the TK high speed of loading pages scalability.
Features of the project:
1) The contents of the catalog are completely taken from another internal service of the company (also written in Laravel), the catalog is synchronized with the base of this service, this part is implemented.
2) Product cards are not sold. Non-functional cards are currently displayed.
3) Incl. the calculation of the delivery of goods to the users region is not implemented. We have a logistics table with several thousand real flights to different regions of the Russian Federation. Based on this table, you need to derive a formula for calculating the approximate cost of delivery (the cost is calculated and displayed in the card of each product), you need an approximate calculation - the exact calculation will still be performed by the logistician manually.
4) The admin panel is mostly implemented, but a number of improvements are needed (TK later).
5) There will be no online payment.

Now we need to bring this MVP to mind and release it in prod. Then we will proceed to the next stages of the project development, for example, the development of a personal account with the history of orders sms / email notifications, import of documents for each order from Bitrix24, etc., but we do not talk about them yet.

Payment is phased, you determine the stages yourself. It is desirable that for the first time this project becomes your main one, or one of the main ones, because the implementation time is already very long.
In the comments, please clarify your work experience, conditions (contract, payment) and give a benchmark for the cost.