Working within a schedule

I have new work on the horizon, and I have to juggle designing and programming. Context switching is a bitch, but I've got to do it and do it well. I'm starting work on a new product tomorrow, and during the next three days, Identify current UX flaws, set up user-flows, create a design system, look through client feedback, etc.
The product is a business intelligence tool in the eCommerce/Shopify ecosystem. It is pretty interesting; this time, currently in BETA, this product seems to be going super well despite its terrible UX and UI. They sort of found product-market fit, but half of the product is still under consideration. I'm curious to see what I'm going to come up with.

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