Finalize WordPress WooCommerce Checkout Flow -- 2

I’m looking for a skilled WordPress developer to connect and finalize an already-developed custom service calculator and a custom 4-step checkout process.

What’s already done:
The custom service price calculator is fully developed.

The 4-step checkout flow is also designed and built.

I have the API for the payment gateway ready and documented.

What I need:
Link the calculator to the WooCommerce cart (add total price as a product or cart item).

Ensure smooth transition from calculator → cart → custom checkout.

Integrate the custom 4-step checkout with the payment gateway via API.

Make sure the full purchase flow works flawlessly from start to payment confirmation.

Requirements:
Strong experience with WooCommerce, custom flows, and API integrations.

Must be comfortable debugging and polishing existing custom code.

Ability to ensure all components work together smoothly.

This is a clear, contained task for someone who knows their way around WordPress and WooCommerce. I need someone reliable and efficient to connect the dots and finalize the system.

Please share relevant past work or similar integrations you’ve completed.