With a PHP background such as yours, I'd very strongly suggest Go over Rust. You'll pick up Go very easily (far faster than Rust, which has a high learning curve), Go jobs pay as well as Rust, it's in high demand, and it's going to remain in high demand for a long time. Most people can become productive in Go the first week they start learning it. Go lends itself to a webdev orientation far better than Rust; Rust is very weak in the webdev arena, you'll be endlessly frustrated by that fact.
My background is 25 or so years of webdev experience, with an early background in Java, Perl, ColdFusion and I've been using PHP since 2005 or thereabouts (I use it for CRUD work). Over time I added Python and then Go. I was able to be productive in Go immediately, and you'll find similar stories all over the Web. It's mostly a delight to learn.
I've also been handling nearly every aspect of the backend infrastructure for two decades now (servers, cache, security, database, etc), and Go is also very nice to deploy. It's dead simple and lightning fast for most things.
One side note, if you don't have much experience building APIs, I would put some focus there in tandem with Go. Being good at building and deploying APIs is a valuable skillset to have. I regularly use Go for such services and it performs like a champ.
Out of curiosity, what's the appeal of learning Rust ? What kind of projects do you use it for ?
I find that I can solve mostly everything with a blend of PHP/JS, but I also never escaped web CRUDy stuff, and PHP is very well suited for these.
Personally I would say learn it because it's one of those languages that changes how you think about programming as a whole and learning it will make you a better programmer in every language.
That said, I think Rust shows the most promise in a few places:
1. Pretty much anywhere you'd historically use C or C++.
2. WASM
Because Rust can expose C style FFIs you can use it to speed up hot code paths in almost all scripting languages(Python, Ruby, PHP, JS etc). This can be very useful because it allows you to keep most of your code in the scripting language that you and your collaborators are familiar with, while benefiting from Rust's strengths too.
For WASM I think Rust is currently the best choice, it has excellent tooling to work with the web, it's by far the most approachable suitable language for someone who already knows JS, and it doesn't have a big runtime or GC which makes many languages non-starters for the WASM usecase.
Some people would tell you it's a good choice for general purpose backend and there is an ecosystem around that, but I would say if that is your goal Rust offers nothing that Go doesn't do better or at least as well.
It has some nice features. Personally I never found myself besotted with it, in fact I rather dislike it and suggest ada instead. But rust is much more likely to get you a job.
Still playing with it for funsies, though.
Ada is part of the Pascal family, but goes further as it were in all the Pascal aspects, making it essentially the ultimate Pascal. In that regard it's interesting just by being different from C.
It's much more verbose than a lot of languages, which some people like, some people don't, I do. But even if you don't, it's nice to explore some of the design decisions taken in a language designed for use in large-scale systems with long lives.
It was created as /the/ language of the US Department of Defense, which once again may not interest you. I think that in itself makes it exciting, despite having almost no interest in any other aspect of the US.
The compiler has a linter (I guess is the right word) built in, similar to Go or something. It also checks for all sorts of other little errors or potential problems like misspellings, scope, overflows, and off-by-ones. As a language designed to be used in systems controlling space equipment, train networks, and other massive and important things, these features are quite important. I guess more languages have these things now but they were an Ada priority from the beginning.
Useful is definitely relative and for a lot of things Ada won't be the best choice. I've used it for very little, but I think it's a really well done language for the most part that suffers from not being so popular. Now that a lot of other systems languages are getting thrown around - Rust, Go, and things like Nim and Zig - I think Ada should get a share of the light too.
But ultimately I just think that "learn Rust" is said much too often with much too little justification when so many other languages that could be equally as enlightening or fun are around.
Here they come! Right on cue.
"ESP32 Tutorial using MicroPython - Let's Get Started!" https://www.youtube.com/watch?v=QopRAwUP5ds
A ESP32 mounted on a breakout board is super easy to pickup and run with-- https://www.adafruit.com/product/4172
However, it's always good to learn more. I have a couple of suggestions:
1. Rust. The Rust book is an excellent introduction to lower-level programming languages, and also to more functional patterns. I went into it from a primarily JS/PHP, and it's been a wonderfully refreshing experience. And it's also been an excellent way to level-up my programming experience.
2. Embedded programming. Get yourself an Arduino or an ESP32, and make something that connects to the physical world. Lot's of fun. You can technically combined this with Rust, but I'd recommend sticking to C/C++ for embedded work (at least at first) because it's much better supported.
3. AWS / Kubernetes / Cloud computing. Managing large amounts of infrastructure on these platforms is an art unto itself. And it's worth learning if it's something you have an interest in. I'm not usually a "training" kind of guy, but I'd recommend doing some kind of course / using structured learning materials for this. Because there's so much tribal knowledge that needs to be acquired.