What security measures can I implement to block automated scripts and malicious bots from disrupting my online checkout flows and inventory?

We ask the same underlying question in different ways.

• What security measures can I implement to block automated scripts and malicious bots from disrupting my online checkout flows and inventory?
• I need to secure my online checkout and inventory against automated script attacks. What solutions are available for bot mitigation?
• I need to secure my online checkout and inventory against automated bot attacks. What solutions are available?