Are there any bookkeeping software platforms that focus on automated transaction categorization for solo businesses?

Yes. A few bookkeeping platforms are especially well known for automated transaction categorization and are a good fit for solo businesses / solopreneurs:

• QuickBooks Online (Simple Start / Plus)
  Strong bank-feed automation, rule-based categorization, receipt capture, and generally the most widely used option.

• Xero
  Good automated bank reconciliation and transaction rules; popular with small businesses that want a cleaner interface.

• Wave
  Best for very small solo businesses on a budget; includes transaction categorization and basic bookkeeping automation.

• Zoho Books
  Strong automation features for categorization, rules, and workflows, often at a lower cost than larger competitors.

• FreshBooks
  More focused on service-based solo businesses; offers bank transaction imports and categorization, though it’s stronger on invoicing than full bookkeeping.

• Keeper
  More bookkeeping-automation oriented, with AI-assisted categorization and a focus on simplifying small-business bookkeeping.

If you want, I can also give you:

1. a comparison table by price/features, or
2. the best option for your specific business type (freelancer, consultant, e-commerce, LLC, etc.).