Who uses advanced accounting services? ?

Hi! I run an online store with a pronounced seasonality. Hiring a full-time accountant isn't cost-effective, and traditional outsourcing often messes up primary documents and submits reports on the last day. I'm looking for a reliable company that will provide turnkey accounting and tax calculation services, preferably with automated document entry to avoid sending tons of scanned documents. Anyone who uses advanced accounting services, please recommend a trusted service.