Help With Slow Wordpress Backend

Description

We are a WooCommerce store that has recently seen a spike in ram and CPU usage, leading to regular 502 errors on both the front end and back end. This makes the backend unstable and means any significant changes to products or orders, frequently lead to page time-outs.
I have tried using a number of debugging and logging tools to identify the issue, but have struggled to identify anything specific due to limited development knowledge.
We require a developer to look into this issue for us and identify what is causing the spike in usage. From there, we would ask for the site to be optimised accordingly (depending on issues found) to hopefully rectify the performance issues.
Please ask for site URL and for more information if required.
BUDGET FLEXIBLE - PLEASE PROVIDE REASONABLE OFFERS