Your AI feels slow? Maybe it's not dumb—you're making it work one thing at a time

📖 Originally published on my blog . Part of a series on building with Claude Code. For a while I'd watch the AI work and quietly grumble: a fairly big task, and it would finish one module before starting the next, while I just sat there waiting for it to clear one before the other's turn came up. The work itself was fine—it was just slow. Slow because it was stuck in a queue. Then it clicked: a lot of these modules have nothing to do with each other, so why make them go one after another? Split them up, let several agents work at the same time, done. What I want, and where it stops What I want is simple: the same work, for roughly the same tokens, with the wall-clock time cut way down. But let me put the boundary up front— not every task can be split this way . This is just an approach I've worked out for myself; take what's useful. The prerequisite: a clean architecture For several agents to work at once without stepping on each other, the prerequisite isn't the AI—it's your architecture . That task of mine could be split because it was already several modules, talking to each other through interfaces, with internal implementations that don't affect one another—as long as each one honors the interface contract, it can be built independently. Loosely coupled, highly cohesive, in other words. And I'd nailed that design down together with opus before writing a line: opus helps me think it through and lays out options, but I'm the one who decides . You can't cut corners here. Forcing parallelism onto an architecture you haven't cleanly split is like cutting a tangle of yarn into a few pieces that are all still knotted together—it only gets messier. Who runs the show, who plans, who does the work With the design settled, it's time to assign roles. The split I tend to use: opus runs the show —holds the big picture, hands out work, does the final check; sonnet does the TDD planning —per the design, it lays out how each module gets tested and implemented; haiku writes the