Premature optimization is not about "optimizing before you need it", it's about optimizing before you've measured it. In this case, you have already measured it

Premature optimization is not about "optimizing before you need it", it's about optimizing before you've measured it. In this case, you have already measured it; you know the cost. There's nothing premature of optimizing at this moment. I would consider spending a day profiling the current setup to figure out exactly how much you could optimize. > and takes a lot less programmer time I don't see how this is true. You've already spent time setting up a distributed system from scratch (pretty much at least), and you also need to maintain it. Distributed systems are complicated stuff; lots of stuff that can go wrong. If the optimization made it possible to use a single machine, it would be much easier to grasp and debug.