We know nothing about the details, of course, but there's something fishy about the performance story. If I were to take a guess it sounds more like a problem w

We know nothing about the details, of course, but there's something fishy about the performance story. If I were to take a guess it sounds more like a problem with misconfigured software than having used fundamentally wrong tools for the job. It sounds like the concurrency was set much too low. That's not limited to the configured max workers but there will be similar settings for the web server, database connection layer and the database itself. A similar thing would have happened with C++ or Java if there was a connection pool of two and database queries that took 500 ms to complete. I've seen worse mistakes in producion code. The lesson to learn from this is probably not that goroutines makes everything faster, but that you have to understand the tools you use. Also, test demos. And always keep a backup plan. That's what Steve Jobs did, relentlessly, for all his demos.