Claude Code Tip: Enter ultrathink when tasks become more difficult to boost reasoning effort for the current turn.

Addy Osmani shares a Claude Code tip: when tasks prove more difficult than expected, typing ultrathink during the session boosts reasoning effort for the remainder of that turn. This feature is available in the latest terminal versions. He cites a post by @dmwlff noting that ultrathink has returned to the Claude Code CLI after being shut down previously for appearing odd and potentially confusing.