You’re leaving a W2 job and starting an LLC (no partners or employees)

You need banking, invoicing, expense management, taxes, and a credit card.

Whats your software stack to keep life as simple as possible?

Banking: Mercury/Brex
Invoicing: Stripe
Expense management: Brex
Credit card: Brex

Briefly used Puzzle for bookkeeping, and no experience on taxes side.

I heard good stuff about Ramp too, but they do not provide business accounts unlike Brex. Never tried but arc.tech also seems very useful on the banking side, especially with the treasury accounts etc.