"My 2015 Programming Languages Tool Belt"
March 25, 2015
A friend of mine approached me recently with a question: "What are your current thoughts on go-to platforms for building web apps? What would you choose for a web app? Ie. app that both should work as API, admin console, some end user facing stuff, etc".
Because this is a topic I've been recently researching I find a reply to this question a fantastic way to express my current point of view. Let me first set the background and tell you where I'm coming from.
The change to my relationship with Ruby correlates with my interest in programming languages in general, and getting familiar with the ones that showed up in the last ~decade in particular.
Let's come back to my friend's question. Even though he asked about "go-to platform for web apps" I replied with a list of languages I would consider using for building software in general these days - my programming languages tool belt. The list includes both the ones I'm familiar with and the ones I'm looking at from a close distance. It doesn't include my pre-Ruby languages though, as I either don't enjoy them anymore or I simply find them problematic these days.
Here's what I replied to him (edited):
Ruby/Rails. These days I find Ruby not really well suited to anything that's more complicated than a simple CRUD app or a reasonably simple API. I've been using it professionally for 8 years, and I've seen too many Ruby (Rails in particular) apps grow and become a mess which is extremely hard to work with and reason about. And that includes projects built and maintained by experienced software engineers too. That's in part because of the "Rails Way", which leads to achieving results quickly, and in part because of the Ruby language itself. In last few years I've seen many Ruby/Rails developers looking for solutions to build bigger things with this stack. But it requires a hell lot of a discipline and experience from the whole team. Also, by not following the "Rails Way" you loose ability to benefit from the Rails ecosystem and its plethora of ready made gems. The other part is Ruby, which is a very unpredictable and unreliable language. No proper namespaces/imports so everything is essentially global. Everything is mutable during runtime. Good luck chasing issues in your app after adding a new gem to your Gemfile which happens to monkey patch something etc. And last but not least dynamic typing doesn't "scale" in Ruby (does it scale anywhere else?). After writing several things in statically typed languages I don't trust most of Ruby code (even mine!). Every change brings anxiety and requires additional tests that check things that you wouldn't have to check if you used a language with static typing. I could go on about Ruby/Rails for hours :) But my opinion these days is that this stack is nice to build something simple very quickly. Sustainability and reliability is not its biggest strength. Job market visibility is pretty high though so it's worth having it in your skill set if you're deep into "web" apps.
Go (aka Golang). Given a fair amount of lines of code I wrote in Go I think I got to a point where I finally see its use cases clearly. It was a perfect match for git-archive-daemon and gitorious-proto (ssh and http repository access). It brought safety and speed to this critical piece of Gitorious backend. It really shines when you do systems and/or networking stuff. On the other side, it kinda sucks when it comes to modeling domain logic. It's neither OO (structs with behavior but that's it), nor functional (has closures, has functions as first class citizens, but no functional constructs), and while being statically typed it doesn't have generics which makes you write the same boring, imperative code for anything that is slightly higher level. Concurrency built into the language in the shape of channels and Goroutines makes it a fantastic fit for building robust, high-scale, multi-core, networked apps though. It's great for command line apps too, because these don't usually have lots of business logic, most often they deal with files, streams and network, and it's awesome to have a single self-sufficient binary for distribution. I'm not sure if I would build a whole "web app" (API, client facing pages, admin part) in Go. Probably not. I'd probably limit the Go part to API, but only provided that the business logic isn't very rich in that case. I haven't written an actual "web app" in Go yet, but I have a strong feeling that it is too low-level for that. I can also see risks when it comes to finding libraries that relate to other stuff than systems/networking. That's probably one of the reasons why I would be cautious when considering it for a typical web app. One thing I'd like to point out here is its learning curve. Go is one of the most easy to learn languages out there due to its explicitness, simplicity and thin syntax surface.
Clojure. It's a language I now use in place of Ruby (when I can). It solves many of the problems I have with Ruby. It has proper namespaces/imports, immutable data structures and trivial syntax (it's pretty much only an AST after all). These 3 alone put it in a more favorable position than Ruby when it comes to building something slightly bigger. It's very pragmatic - it's highly functional but it allows you to use atoms, refs and other state-keeping constructs when you really need them. It also allows you to access IO with no fuss (spit/slurp functions for example), contrary to other functional languages like Haskell, where IO is pushed to I/O Monad. This makes it a really approachable functional language. Thanks to macros it supports pattern matching (core.match), gradual typing (core.typed) and sane async programming, similar to Go (core.async). So I see Clojure as a "much better Ruby, which runs on JVM" (and I think being on JVM is a plus here). Clojure is dynamically typed just like Ruby (which also has many functional constructs), hence the comparison here. Oh, it also has ClojureScript/Om which brings sanity to building rich browser UIs \o/. One downside of Clojure is its low position on job market. It's getting better with every year though.
Haskell. I haven't used Haskell on a real-world project yet but it seems to have all the ingredients I'm looking for in a language today: functional, immutability, serious type system, powerful pattern matching, and failure handling with Maybe type. Btw, I talked to a guy on LambdaDays conf recently who owns a consulting company that began as a Rails shop and now they're moving towards building their web apps in Haskell. 6 out of 25 Ruby devs switched to full time Haskell already, and more to come. Interesting, isn't it?
Scala. This one got my attention recently again. It has more or less the same qualities I find in Haskell: functional (mostly), immutability (mostly), static typing with generics, Option (Maybe) type, powerful pattern matching. I wrote some small piece of code in Scala some time ago, but I did it in a very imperative, and not really idiomatic style back then. I'm inclined to try it out again on some side project, there are several things which put me off a bit though. It's very close to Java, so it's close to XML/SOAP/Enterprise ecosystem and type of work/projects. It also has like a half-dozen types meaning "nothing": Null, null, Nil, Nothing, None, and Unit. O_o. This may be nitpicking but it doesn't show it as a consistent and simple language IMHO. And its "syntax surface" feels to be very wide, which is something I try to avoid these days. From HR POV it's definitely not as "dramatic" as Haskell or Clojure.
Rust. I looked at it recently and I find it to be a way better designed language than Go (if we compare languages advertised as "systems language"). Functional constructs built-in, immutability, static typing with generics, Option type, powerful pattern matching, and no exception handling (solved by Option). <3 <3 <3. However, there's one thing I miss in Rust: garbage collector. I understand why it's not there. They (Mozilla) wanted systems language with predictable performance, that would replace C++. And I think it delivers on that promise. But that makes it a bit too complicated (memory is managed for you but with your help) and not well suited for building web apps. I guess I could have skipped Rust in this already long list, but I love discussing programming languages recently, sorry. Note that I compared Rust to Go in the first sentence of this paragraph, but it's only because both are called "systems" languages. In reality they seem to have different use-cases and excel in different niches.
Elixir. It's on my list of languages to have a closer look at. It builds on Erlang/OTP and as Erlang it is best suited for building scalable, fault-tolerant distributed systems. It's dynamic, functional, has pattern matching and includes several Ruby-inspired features like modules/mixins and similar syntax. Phoenix seems to be its most popular web framework. If I had to compare it to other language from this list it would probably stand somewhere near statically typed Scala with AKKA toolkit/runtime. Feel free to bash me for this comparison.
So, this list didn't really give a direct answer to my friend's question. But I hope it is still useful for him and anyone else looking for a great tool to fit for the next job. There's no single programming language that excels in everything and it's important to understand that languages are just tools. Sometimes I'm choosing multiple languages for different components of a single system (Gitorious' frontend was a Rails app, its backend was built in Go and bash). Sometimes I'm building UI as a HTML5/JS/ClojureScript app, fully decoupled from the backend. It all varies from case to case.
I hope to have lots of opportunities to try more of these "tools" in the future, finding out how well they fit specific applications, and adding the proven ones to my programming languages tool belt.
I'd love to discuss this topic more so I'm looking forward to your opinion on this!