First off, most of those languages/frameworks aren't even modern, let alone "more modern" than PHP. Next most of them are not significantly faster than PHP, if

First off, most of those languages/frameworks aren't even modern, let alone "more modern" than PHP. Next most of them are not significantly faster than PHP, if they're not definitely slower than PHP. If you're not using modern PHP, you can upgrade to PHP7.x faster than a full rewrite. I would avoid rewriting anything non-trivial, because you have no guarantee that your new codebase will be completed in a predictable amount of time, let alone be faster. If a specific sub-module needs to be in a faster language, rewrite that small part in something like golang or elixir. You need to be really careful with full rewrites, you're more likely to end up with a whole year of lost productivity than a success story. I'd recommend learning how to profile and optimize performance _after_ migrating to PHP7+.