Few days ago I’ve received email where I was asked for an advice from a web developer who was considering switching from Ruby to something else. I was asked in the email:

If you would start from scratch, what would you choose: Ruby, Elixir or maybe even JS for the backend?

Another important part of the email was that he was mainly interested in writing own side projects where main consideration is development speed and ease.

I’ve started to write a response when I’ve realized the email is quite long. So I’ve decided to turn it into an article.

So for those interested on my take on this here it is.

First I’ll go trough some philosophical points of web-development, work life and then I’ll shine some light on the technologies themself to better explain what they aim for.


To long to read ? I’ll place the conclusion to the top of the article then and you don’t have to read the rest.

In retrospect I would choose “Ruby on Rails” as my primary technology again even in 2018.

I like the projects that this technology attracts (startups mostly) and people similar to me I meet on the journey. So it’s my personal choice, you may be different.

Rails is not obsolete, Ruby is not dying (they are more awesome then ever before) market for this technologies is really good ($$$).

Anyone who want to fight my opinions pleas read the entire article first. Thank you.

I would focus on my primary tool (Rails) at the same time I would keep learning plain Ruby, Elixir, Phoenix and JavaScript as my side tools (everyone can find 20 minutes a day).

I wouldn’t spend too much time learning programming languages outside that list as you need more tools in your toolbox but too many tools may get your toolbox cluttered and not really able to have the skill required to operate the tool. Rather learn underlying technologies an problems, like Databases, Caching, Coding practices, DevOps, team maintenance, testing, …

You can learn new programming languages when you are senior developer.

They are just tools

Any programming language any library any framework any database any coding rules: they are just tools.

You may want to use hammer when you are nailing a nail to the wall, or maybe when you want to smash bricks you would use a bigger hammer. But using hammer to fix a car may not be good idea.

Truth is that during your career you will be forced to use / try / learn multiple different technologies and different product development approaches. Being a web developer is not a job but a lifestyle !. It’s a never ending cycle of self improvement.

Re “lifestyle”: I’m not talking about work-life balance, I’m talking about work-life mindset. Developer is like a MMA fighter, you will have to learn and endlessly practice different martial arts.

So you need to realize that it’s not just programming languages that are important but also technologies that the programming language works with (databases, cloud solutions, caching, libraries ….). Also important are architectures(Monolith vs Microservices), team organization practices(e.g. agile, Scrum, Kamban, XP, github-flow,…), coding practices & styles(SOLID, DCI, bounded contexts, OODD, many many more …) Programming language is just the glue.

You can work with the fastest programming language out there, but still if you have no idea how to effectively query in a MySQL database you will create supper slow application.

Developer happiness

You will work with that programming language 8-10 (maybe even 16) hours a day. Don’t underestimate the importance of “developer happiness”

If tools that you work with or the project that you work for doesn’t make you happy then it’s you that failed not the Programming language.

I love my job because I’ve picked a job with the right set of technologies, with the right team, with the right project that has the right set of values.

Junior developers often have to sustain jobs that they may not like to gain experience but I honestly don’t understand how in the year 2018 any decent senior role web-developer may be miserable in his job. There are definitely days that are stressful or frustrating but those are temporary states. But miserable ? Either change the project/job, the technology, or the way how you work (e.g. push for remote working). If none of that is possible then you are probably not that decent web-developer after all and try work on your self improvement harder (then revisit this paragraph in couple of months.)

Working 10 years as a web-developer doesn’t mean you have 10 year experience. Maybe you just repeated the same year 10 times !

No winners

There is no “bad” programming language, only badly chosen project where you would use that programming language.

Way to often I hear or read software developers dismiss languages like Ruby as too slow” not realizing that their strength was never the speed. Lot of times when you investigate background of those claims you will discover that someone was trying to fit couple of thousand request to non-load balanced server or had no idea what caching is.

Developer need’s to focus to optimize overall performance of application with tools like newrelic not focus on how many loop cycles the language can handle. You are building real life applications used by real people.

Often I read developers complaining about languages like Java as too complex or non-pragmatic for real applications. Those languages were designed for enterprise use where applications are developed in larger teams with the desire to run couple of decades. For example banks will choose Java over Ruby without hesitation. The main reason is that Java almost never drops a feature (even the bad ideas in languages are supported pretty much forever once they were released). Ruby feeling less pressure from enterprise giants can afford to do radical changes that may break code but introduce better features more often.

If you are working on Google size project with a billion users you may not want to use Ruby. At the same time if you are at that size it will be nearly impossible to deal with a monolith application. You would most likely deal with a form of microservice architecture where the limitations of the language would be hidden behind smaller chunks of application running on different servers.

more on monolith vs microservice

It’s often to see some major companies move from one language to another simply because the language no longer make sense for their scenarios. Years ago Twitter moved away from Ruby because they became this giant social media monster. Github needed to refactor parts of it application to different technology as well. That doesn’t mean the original language was a mistake. It was good choice at the time that helped them to grown into what they are now.

This happens not only with programming languages, but also with databases (SQL vs NoSQL), or storage solutions (Dropbox moved away from AWS S3), or.. pretty much anything ! It’s only programming languages people tend to freak out for some reason.

It’s perfectly normal to let go.

Also we see this countless times with monolith applications becoming refactored into microservices when they become too successful.

If you are startup that has only couple of thousands in founding to develop a successful application from scratch you will burn that money before you ever launch the product if you choose something unnecessary complex like Java or even Elixir Phoenix

Yes Elixir & Phoenix is awesome and really really productive but lets be honest here: Rails is much faster for product development speed.

When a brand new startups without previous web-development experience drafts out requirements for they “revolutionary” project, almost always one of the requirements is: “it needs to support million users”. Because it’s obvious that the product will be overnight success. The ego plays huge role in downfall of many such companies. Six months after the launch they will probably have couple of thousand users not more. It’s ok to prepare for a larger traffic but honestly don’t kid yourself.

Investment in supporting overoptimistic expectations always comes with price of delivery time. You can build same feature in couple of days, weeks or months depending whether it needs to withstand traffic from couple of hundreds, thousands or hundred-thousands of users.

In highly competitive market survive those startups that are able to adapt existing features to requirements or introduce new features quickly. Those that won’t be able to keep up fade in time. Your customers and investors don’t care that your application can potentially handle two million users if the application experience sucks so bad than only couple of hundred will use it.

Like I said it’s always goes from project to project. You may be building a chat application where Ruby would struggle from day one and Elixir will dominate. You really need to analyze the bottlenecks of the project.

Reason why I stick with Ruby (and mainly Rails) is simple: I love to work on projects where I develop many interesting features rather than I spend months optimizing the heck out of same one feature. I deliberately choose projects that are neither too large or too small. Medium size projects are always fun and challenging just the right way.

So really ask yourself what projects would you want to work on in couple of years and according to that choose the technology.


Don’t underestimate the size and nature of the community as well. Too small language community may mean that there are not that many libraries and senior developers willing to jump to fix the bugs.

Too larger programming language communities may get toxic pretty quickly. It may not sound as a big deal but I’ve heard stories where community around certain language was quite cool and open minded when it was small but as soon as they start dominating market and gaining popularity they become more a political correctness group. Long story short some decent friendly developers were highly criticized over minor jokes they say on social media.

I’m not going to name that language as it would just spawn a fire of outrage comments from that community. It would just prove my point but at the same time I’m not suicidal.


Ok lets finally analyze the languages in question:

Ruby is an excellent Object Oriented programming language where the primary goal (in my opinion) is excellent OOP experience and developer happiness. But speed of the code is not a primary goal.

Ruby on Rails is web framework built upon Ruby language where the primary goal is productivity and developer happiness. Speed of the code and true decoupled OOP experience is not the main goal and socket connection is ok but not great.

Elixir is excellent functional programming language where the primary goal (in my opinion) is multi-core processing (code speed) and socket connection support while keeping in mind developer happiness and reasonable productivity.

Elixir also has Phoenix web framework but more you read about it more you understand that it’s really collection of libraries that go hand in hand with Elixir primary goals.

Therefore Elixir vs Ruby vs Ruby on Rails :)

My explanation sounds really similar but devil is in the details:


More you will learn deeper concepts of object oriented programming (SOLID principles, object composition, DCI, object oriented decomposition and design, simple design, bounded contexts, DDD, BDD, TDD, etc..) you will discover how well Ruby works with these concepts.

My opinion is that Ruby is the best language to express yourself which is more important than some developers tend to admit. Most of your career you will work in a team. It’s important to understand what you and your colleague try to say with the code (it’s called language after all)

It’s often misconception that one cannot build much usable web-applications with Ruby without Rails. There are several alternatives out there (e.g.: https://hanamirb.org, http://sinatrarb.com)

Remember that Ruby is generic programming language not just web-development language. During past 9 years I’ve manage to build several dozen custom plain Ruby CLI tools for personal use and companies I’ve worked for. Applications like Google Sketchup are running Ruby and in Japan Ruby is quite a preferred language.

Every now and then you can find an article that Ruby is dead but rarely those articles provide any evidence. Usually those articles are just developers personal opinions or personal experiences not tackling global data. Just because one company decides to use other technology doesn’t means that the entire language is dead.

Ruby is very much alive:

…just because Ruby is not the major player doesn’t mean that that is bad. Like I’ve explained in the community section, it may be actually preferred state.

Ruby is around for over 25 years now. It will not go away that soon.

To provide full perspective more often with evidence you read how Rails is falling in favor e.g. this article on how Rails is being replaced in coding bootcamps. I’ll get to that in next section

Ruby on Rails

Rails a framework (collection of libraries that work well together) but is also a philosophy on how to write code so you build your products fast.

Many developers from different languages jump into Rails world without realizing history and highly different system of values:

More you read and truly understand intention of Rails you will discover that the way how authors propose solving problems in 2018 are similar then those from 10 years ago because they just work. Server rendered HTML & CSS with sprinkles of JavaScript (and yes RJS is still a thing).

Proof that that approach works is Basecamp and Shopify revenue (they are profitable) and developers are happy (source)

Many things in Rails are coupled together because they make developer more productive. For example the way how Rails models write directly to database or how Frontend is coupled with Backend by default.

Now the biggest trend out there these days are SPA (single page applications to which Rails is not oppose to, Rails authors just prefers not to use SPA.

So you can build SPA frontend with Rails but it will definitely have it’s own unique taste. Only recently Webpack was introduced to Rails 5 as standard thing. Up till certain point Rails Asset pipeline (via ruby gems) render SPA lib was common thing. This created tension between Rails Backend developers and Frontend only developers that dislike this shotgun marriage of JS and Rails.

Another approach is to just generate Rails application as an API only and just have SPA on a completely separate VM but that add extra step for DevOps and developer team synchronization as you are literally building two different projects now.

So the point is that Rails prefers not to use SPA but if you want to use SPA there is at least 3 different ways how to use them now days. This in my opinion sends a confusing message to Rails newcomers that wont to learn and also coding bootcamps that want to teach latest technology “trends” like SPA. So they just drop off Rails in favor plain JS backend.

I’ll explain why in section reserved for JavaScript language.

That’s why it may seen that Rails is dropping in favor. But is not. Boot camps may just gave up Rails but startups are still choosing it for new projects.

Remember one thing from this. Just because something is trendy it doesn’t mean it’s the only way how to do it. We seen this several years ago with NoSQL databases. There was a huge movement on how databases like MongoDB, Casandra, Riak will completely replace SQL database like MySQL or PostgreSQL. And guess what, they didn’t. There are scenarios where you want to use SQL database there are scenarios where NoSQL database makes more sense.

Another similar trend these days is Microservices. Same scenario. Everyone is saying how microservices are the “best practice” how to do applications in 2018, yet they don’t explain you will run out of money before you release the product.

Anyway, developers may find Rails good for monolith applications but for microservice you may find it bit too heavy in memory. So you would pick something lighter like Sinatra.

Same will apply for “best practices of coding”, “best practices of testing”, deployments, …

Every team and project is different. It’s up to you to sit down and discuss with your team how you are going to build the project, what technologies you want to use and create a plan to which you would stick to. Worst thing you can do to a project is to change opinions all the time.

So if your main concern is “development speed and ease” then I would go with Rails without SPA (turbolinks is more powerful than you think). Especially if it’s just one man project (not a team of developers)

If your main goal is to have a separate team of FE only developers that will write just SPA JavaScript and team of BE developers that will just provide SPA then go with Rails API only option (rails new myapp --api)

If this API needs to really handle lot of traffic use Rails but maybe check engine alternatives like Eventmachine That being said, default Rails Puma webserver is really powerful too. And if you learn to apply caching properly you can get away with a lot.

If you need mega traffic on your API (like millions of requests) then Elixir/Phoenix may be much better choice.

I heard a story in one podcast that in one USA city had their crime reporting software running on Rails on like 6 servers on average due to heavy traffic. They refactored it to Elixir and they have it on 2 servers. They really need just one server as average load is 30% but they keep two servers up just in case one goes down.

Elixir & Phoenix

Elixir is an excellent functional programming language where primary goal (in my opinion) is multi-core processing (code speed) and socket connection support while keeping in mind developer happiness and reasonable productivity.

Phoenix is web framework built in Elixir language but more you read about it it’s really collection of libraries that go hand in hand with Elixir primary goals. So there is not a major philosophy fight between language and framework.

Elixir is built upon Erlang VM which is really powerful functional programming language designed for telecommunication industry where you need to guarantee fault tolerant system If you have telecommunication tower deep in the forest it better run on 99.9999999%.

Other requirement of telecommunication industry that Erlang fulfils is that one communication tower can take over responsibility of the other tower so caller don’t experience interruptions. Some smart people noticed that this distribution capability matches multicore communication requirements and therefore if you have server machine with lot of CPU cores (like 32, 64 and even more) Erlang will be able to effectively execute your application on all of them.

You may argue that there are already lot of OOP languages (like Java or even Ruby) that handles multicore. Well newsflash, all OOP languages sucks at multicore processing. Yes you can do it but you will not get to results like with Functional programming languages.

Root of all evil is state. It’s supper hard to exchange state without mutations between CPU cores. As OOP is functions+state you are done.

Functional programming languages don’t mutate state that means no side effects. (I’m explaining it in more depth here)

So as Elixir is built upon Erlang this benefit is passed on to it too.

Another important point is socket connections. You see any webserver can handle request&response type of communication. But when you are building real time application (e.g. chat, videocall) you need to use “sockets” that means to hold connection on your server.

Now Rails or Java can handle couple of thousands on one server at once.

Erlang & Elixir can handle like 2 million connections (Erlang proof, Elixir proof). Truth be told those are light connections on a huge like 40 core CPU and 128 GB RAM server but still pretty impressive.

So Elixir and Phoenix are truly awesome. Why is not everyone using it?. Like I said everything comes with a price. Doh Phoenix and Elixir are trying to do all the best to help developers be productive, when you are a technology that promises such a huge scale you need to introduce practices that need to be decoupled => bit slower for developers.

Good example of this how a “model” writes to database. Module (with schema) need to call a changeset, changeset call repository, repository writes to database (example). That’s 3 manual steps where in Rails you have in in one

Now this 3 steps is much better practice from coding perspective. You are writing clean decoupled easy to test code. But it will definitely take more time than with Rails. Rails has worse coding practice but implementation is focused on productivity and faster implementation time.

It’s not a design choice. Functional programming is more explicit way of writing code, so you need to pass everything, therefore it complicates your code (again that’s both good and bad thing)

So if you are building application to withstand lot of traffic, or application that will heavily rely on socket communication or you are working for company that can afford longer delivery time: Go with Elixir and Phoenix

Please watch some talks from Elixir and Phoenix before you jump on the train. Not to distract you but to get you more motivated and understand philosophy not just code. Here are two I recommend:


At least minimum level of JavaScript knowledge is essential for frontend web-development when one is building fullstack side project. So given or take JavaScript must be learned to some degree.

For backend I’ve tried it couple of years ago on a side projects and didn’t like the experience so I’ve never really returned to it. I’m not saying it’s good or bad I just feel it’s not the right choice for me. I’m pretty sure there are many happy Backend JS developers out there I’m just not one of them. That’s why I’ll not say much on JS in this article.

One good argument that I’ve heard is that the developer in modern web-applications can write backend in NodeJS (JavaScript), frontend in React or Angular or VueJS (all JavaScript), BE and FE will be communicating with each other via JSON (JavaScript object exchange) and the database can be MongoDB where you store JSON documents.

So entire experience of web-development feels like you just need to know one programming language. No wonder that coding bootcamps prefere to learn JS these days as it’s a simpler for them.

But like I’ve said in previous sections that’s not true forever. Sooner or later you will reach a point in your professional life where you will have to add more tools to your toolbox.

Also when developing BE with Node JS you will work with “event loop” which is bit different philosophy than you would be used to with synchronous Ruby MRI. If you have no idea what I’m talking about and you understand Ruby try to play around with eventmachine it’s similar principle than Node JS.

One more benefit of JavaScript is also that is supported language on many FaaS providers (serverless) like AWS Lambda.

One last note

There are many many things you need to learn (There are still many things I need to learn) No mater what you choose be prepared you will have to read, study and implement many coding practices in your free time otherwise you will suck no mater what is the language.

Recommended topics to start with for next couple of years:

  • try both object oriented and functional programming
  • SOLID principles, DCI, Simple design, Object composition
  • learn design patterns (e.g. M. Fawler)
  • DDD (domain driven design)
  • Bounded Contexts
  • why to use of TDD and BDD and why to stop using TDD and BDD
  • try FE development even if you are BE developer
  • learn how to be a professional (e.g.book Clean Coder)
  • try microservices, then stop using them.

Techniques like TDD or SOLID principles are good, but they are not unquestionable truth (Yes I said it!) Don’t be religious about them. Definitely worth learning and to apply them when needed, definitely not worth breaking a stable productive team because of them. Much better practice is to be a good team member.

Most importantly work on your own project in a free time. Do the experiments there not on your job project. Bring the knowledge to your job.

Worst attitude developer can have is “I’m not going to learn in my free time, I’ll just learn on the spot in my company”. Web developer is a lifestyle not a job. Deal with it!