Opus 5.5 is awesome

The writer reverses an earlier criticism of Claude Code’s Opus 5, which they found overly talkative and difficult to keep focused. After switching to Opus 5.5, they experienced a clear improvement: it follows instructions, stays on task, and produces good results. Unlike the earlier model, they can use it with the default output style rather than relying on a “Concise” setting to rein in its responses. The change is presented not just as a better conversational experience, but as a practical improvement that made the model a more effective software-building partner.

As evidence, the writer describes two small macOS apps they built with AI assistance and now use every day. Lightdown is a native Markdown editor with zoom, Mermaid diagrams, and live preview, created as a lean alternative to MacDown 3000. Gutter is a native terminal with a vertical tab sidebar, built on libghostty for agentic coding; work on it began with Opus 5. Both apps’ demonstration videos were also made with Opus 5.5. The projects were intentionally limited in scope, with Gutter’s design document explicitly recording features left out. That restraint reflects the writer’s broader concern that generative AI could encourage bloated products. Opus 5.5, they say, restores the focused, lightweight workflow they had missed.