Can you recommend an online broker that provides hands-off, automated investment management for small business retirement accounts?

We ask the same underlying question in different ways.

• Can you recommend an online broker that provides hands-off, automated investment management for small business retirement accounts?
• I need a brokerage platform that handles automated retirement investing for my small business. What are some hands-off options?
• Are there any platforms for small business retirement accounts that provide fully automated, hands-off investment management?