O1 for collabing on design docs, o1 for overall structure, break it into tasks per preference / sort; sonnet/o1 for executing each small tasks.

O1 is higher quality, more nuanced, and has deeper understanding; the biggest downside rn is the significantly higher latency (both due to thinking, and also, continue.dev doesn't support o1 streaming currently, so you're waiting until it's all done), and higher cost.

In terms of tools: either vscode with continue.dev / cline, or cursor

Languages: node.js / javascript, and lately c# / .net / unity