【Rust日报】 2019-07-29：关于创建「更小的」Rust的思考

There are no language X job advertisements.

I think there is a misunderstanding here; you see an advertisement asking for C++ experience and conclude that not knowing C++ you are unfit. There's a slim possibility that you are right, and a near overwhelming possibility that you misunderstood the ad.

Now, before going further, there are possibly some places where "X years of experience in Y" is a sacrosanct requirement; the company may be looking for an expert in Y for some reasons. And there are cases where HR may even believe it is sacrosanct, if they have no idea what they are doing.

In the vast, overwhelming, majority of cases though, "X years of experience in Y" is really a rough guideline:

X aims at giving a hint of the seniority required; 0-1 is aimed at beginners, 2-4 at juniors, 5-10 at regulars and 10+ at seniors. The varying level of seniority is also a hint at the kind of work (senior may imply mentorship, technological/architecture decisions, ...) and compensation.

Y aims at giving a hint at the domain, for example C++ could mean: systems programming (kernel, driver, embedded), high-performance computing (numerical, scientific, machine-learning), real-time (embedded, audio/video), low-latency, ... A technical interviewer would understand that anybody with experience in C or Rust in the same domains would be able to adapt relatively quickly.

The only quasi-certainty in "X years of experience in Y" is that the job involves working with Y; if you don't like it, or do not want to work with it, better pass your way.

Learning

X developers are pointless.

I've never seen a job which required me to only ever program with a single language. There's usually a main language, certainly, but:

My first job was mainly C++, with some SQL, HTML, CSS, JavaScript, and Python/Bash.

My second job was mainly C++, with a lot of SQL, and some Python/Bash.

My current job is mainly C++, with some x64 assembly (debugging), Java, and some Python/Bash. The occasional glance at Systems Verilog too.

Furthermore, the more languages you see, the more your realize just how much in common those languages have. The first time you see a concept, you'll struggle with it, but the fourth or fifth time, it's just like getting back on a bicycle after a couple years, it just comes back instantly.

My advice, therefore, is NOT to make the mistake of focusing on learning a single language in depth and instead aim for breadth:

Computer Science is awesome: data-structures and algorithms are not something you code daily, but understanding them and applying complexity analysis is great.

Languages have a lot of different programming paradigms, in no particular order: C/C++/Rust, Java/C#, JavaScript, Haskell, Python/Ruby, Lisp, Forth, Eiffel, ... Each of these groups bring something novel to the mix.

Real world != assignments: assignments tend to be small, well-defined, and immediately forgotten. The real-world has large code-bases which grew organically for decades and have high-level functional requirements that are only defined on a coarse-grained level (and even then, there's often leeway). If you want early experience with the real world, either find a part-time job at a programming shop or an existing open-source project -- insisting on existing, as it means already large and laden with technical debt.

You could read books, like Clean Code, etc... but honestly, you'll only appreciate their advice after experiencing the mess of the real world first-hand ;)

Broader Learning

Also, just in case you are under the misconception that a programming job is about coding; it's a lot more than that.

Programming also involves:

Communication: English. If your first language is not English, that's your first priority in University -- take extra courses if needed, start reading/writing in English daily, start watching movies in English. If your first language is English (lucky you), but you're not too good at it, then it's also your first priority. Spelling mistakes are an embarrassment in any professional e-mail, fumbling for words in a conversation is always awkward, and having to repeat because you mumble makes you wonder how many times you were misunderstood.

Communication: Clarity & Concision. Remember when I mentioned coarse-grained specifications? Guess who it falls onto to clarify them? YOU! It means listening/speaking and reading/writing, of course. It also means communicating with technical peers and non-technical clients. It means rephrasing to ensure you understood. It means summarizing discussions to leave a trace you can come back to.

Planning. At the very least, planning your work, knowing how to divide a large task in small chunks, understanding business priorities, ...

In Parting

Learning a programming language in depth should be the least of your worries.

Instead you should learn programming in the broad sense: puzzle-solving, navigating large code-bases, communicating clearly and efficiently, and getting comfortable with a variety of programming paradigms and syntax so as to be flexible.

Oh, and if you're looking to get your feet wet by contributing to open-source, may I suggest the Rust community? It's welcoming, and there are a lot of exciting projects on a broad variety of topics ;)