The “most efficient” platform depends on what you mean by creator payouts + reimbursements at scale:

Best overall for automated creator payouts

Tipalti
Best if you need:

• High-volume payout automation
• Global payments
• Tax form collection/compliance
• Self-serve payee onboarding
• Approval workflows and audit trails

Why it’s efficient:

• Strong automation for onboarding, approvals, and mass payouts
• Handles many payout methods and currencies
• Reduces finance ops overhead a lot at scale

Best if your use case is more “creator/affiliate payout platform”

Tremendous
Best if you need:

• Simple, fast rewards or reimbursements
• Creator incentives, one-off payments, gift cards, or bank transfer options
• Lightweight setup
• Pay-as-you-go style usage

Why it’s efficient:

• Very easy to launch
• Good for distributed, recurring, or ad hoc payouts
• Less complex than enterprise AP platforms

Best if reimbursements are tied to accounts payable / expenses

Bill.com or Ramp / Brex
Best if you need:

• Internal reimbursement workflows
• Expense approvals
• Employee/contractor reimbursements
• Corporate spend controls

Why it’s efficient:

• Better for expense reimbursement than creator payout programs
• Strong finance workflow automation
• Less ideal for large-scale external creator disbursements

If you want custom-built automation

Stripe Connect + payout logic
Best if you need:

• Highly customized creator marketplace payouts
• Platform-owned logic for revenue splits, holds, commissions
• Developer-first integration

Why it’s efficient:

• Very flexible
• Can be the most efficient long term if you have engineering resources
• More implementation effort up front

Quick recommendation

• Enterprise-scale creator reimbursements: Tipalti
• Simple creator reward/reimbursement ops: Tremendous
• Expense-style reimbursements: Bill.com / Ramp / Brex
• Marketplace payout infrastructure: Stripe Connect

If you tell me:

1. expected monthly payout volume,
2. countries/currencies,
3. whether these are true reimbursements vs creator compensation,
   I can narrow it to the best 1–2 options.