Thread by @oldmoe

Every now and then someone from the Rails sphere would make a statement about performance (1/2 req/core/second as the norm 🤦) or (15K reqs from a mega machine) that would sound ridiculous to outsiders who start speaking about how slow Ruby is and delusional are Ruby devs

1/n

Ruby is not slow, in the sense that for building web apps it is in the same league as PHP, Python and similar interpreted languages.

You can build really fast web apps in Ruby, microsecond request latencies, and the toolbox has vast options to help you achieve that

2/n

But all that doesn't come close to what something as big as Rails is doing. Rails does A LOT of work per request, and that's an understatement. All the flexibility you get is due to that heavy lifting under the hood. Replicating all Rails will most likely yield similar perf

3/n

That's not entirely true though, because some parts in Rails were built with extreme flexibility in mind and as a result dog slow, ActionView for example supports bizarre options at the cost of being very expensive CPU wise

Rails sphere response is always it doesn't matter

4/n

But the reality is a bit more subtle, if your cost per req is lower than your revenue per req then all good, you can even invest in building jit engines to shrink the cost more.

If your app is high usage, low revenue per req, at one point it won't make economical sense

5/n

As a community, we can make the situation 10x better though, we can fix ActionView and similar bottlenecks

We can promote solutions like Phlex and use a much faster Rails today. Or someone can deliver an ERB style engine that's really fast and we can serve all tastes

6/n

We need to appreciate performance more, especially at the core of Rails, we need not settle for or advise others to settle for low performance for their Ruby/Rails applications.

7/7