This I 100% agree with. The parent post was essentially that Rails doesn't scale and "everything else scales better".
Most battle tested languages and frameworks can be adequately scaled if you have the right devs. I think that a lot of the reason we see system rewrites due to scalability is more because startups tend to hire developers that like to "build new things fast" and those aren't necessarily the same as the developers that have already dealt with 1M+ users at petabyte scale.
Once you become that successful sometimes the solution is to bring in people that have solved these problems of scalability previously. This sometimes results in rewrites in whole or in part because their experience is on a different stack.
In one of the PHP to Rails (for scalability) projects I worked on I was contacted quite early in the process. I am a longtime friend with one of the business owners. The existing developers could not scale the product horizontally and were already on the largest instances available at the time so there was no more ability to scale vertically.
They had hired a new technical lead that had extensive experience scaling Rails, but most of the team only knew PHP. My team did both Rails and PHP consulting at the time and we were hired to speed up the rewrite in Rails while the PHP devs were doing a mix of trying to keep things running and learn Rails so they could support after the rewrite.
The first thing I did was review the existing PHP codebase. I then advised that they not switch to Rails because I firmly believed that in about 3 months the PHP version could be refactored to allow for adequate horizontal scalability. The full rewrite was expected to take a little over a year.
The owner agreed that my assessment was probably right, but he still opted for the rewrite because the new lead was competent at scalability and likely would have quit if they stayed on PHP.
Most battle tested languages and frameworks can be adequately scaled if you have the right devs. I think that a lot of the reason we see system rewrites due to scalability is more because startups tend to hire developers that like to "build new things fast" and those aren't necessarily the same as the developers that have already dealt with 1M+ users at petabyte scale.
Once you become that successful sometimes the solution is to bring in people that have solved these problems of scalability previously. This sometimes results in rewrites in whole or in part because their experience is on a different stack.
In one of the PHP to Rails (for scalability) projects I worked on I was contacted quite early in the process. I am a longtime friend with one of the business owners. The existing developers could not scale the product horizontally and were already on the largest instances available at the time so there was no more ability to scale vertically.
They had hired a new technical lead that had extensive experience scaling Rails, but most of the team only knew PHP. My team did both Rails and PHP consulting at the time and we were hired to speed up the rewrite in Rails while the PHP devs were doing a mix of trying to keep things running and learn Rails so they could support after the rewrite.
The first thing I did was review the existing PHP codebase. I then advised that they not switch to Rails because I firmly believed that in about 3 months the PHP version could be refactored to allow for adequate horizontal scalability. The full rewrite was expected to take a little over a year.
The owner agreed that my assessment was probably right, but he still opted for the rewrite because the new lead was competent at scalability and likely would have quit if they stayed on PHP.