Functional Programming as a Career (Elixir and Beyond)

Who am I?

• My name is Nikolay, some call me Meddle.
• I've been professional programmer for ~18 years now.
• I'm an Elixir developer, doing things mainly on the backend of the world.
• I'm part of the Sofia University Elixir course.
• I'm a musician and a poet, other things too, but that's not important.

Blog: https://themeddle.com
Github: https://github.com/meddle0x53
Bandcamp: https://smerch.bandcamp.com

Who are you?

• People that are intereseted in learning about functional programming
• People that like functional programming but don't work with it?
• People that work with functional technologies (JavaScript??)
• Anyway, we'll be talking about why it is viable option now

FMI Elixir course site: https://elixir-lang.bg

The Past

• Around 15 years ago, to find backend job you had two main choices Java and PHP.
• Why was it like that?
• Well because the requirements...

The Past, requirements

• Nobody required 100 000 users at the same time..
• Nobody required the site to be 99.999% available.
• Nonody required voice over IP.
• Nobody required collaboration in real time.
• Simpler times! (Actually there were niches that required the above things).

But does this super cool search engine backed advertising business site support IE6??

The Past and the niches

• Interesting is, that even in the 80s there were businesses that had very different requirements.
• The Telecommunications Companies!

The Past and the Telecoms

Telecom software had to be:

• Concurrent (had to be able to support 1000s transactions happening at the same time).
• Fault tolerant - To be tolerant to errors and troubles, both software and hardware.
• No down time at all!
• The code had to be replacable while they were running (see the above requirement)

The Past and the Telecoms

Well, there was a language/technology/ecosystem designed for that:

Erlang!

The Past and the reality

• That's true but that was a niche thing. There were others like that.
• The great imperative OOP idea was the corporate buzz word.
• And that's normal, most computers were with CPUs that had just one core and not much power.
• Requirements drive the marketplace and that's OK!

Times change!

Times change!

• With time we started receiving similar requirements to the ones of the Telecoms.
• For example Netflix came with the idea of streaming movies to the homes of its customers.
• What were the requirements : multiple concurrent data streams to 1000s of users.
• What they did to acieve that : they came up with RX (The Reactive idea), a very functional idea.

Times change!

• Computers got multi-core, more powerful, great ideas of the past that were not easy to implement before were now possible.
• Collaboration software - collaborate on writing books, designing UI, coming with diagrams and ideas!
• Servers had to be very concurrent, state had to be shared between 1000s of people at the same time, threads and locks were getting complex!

Life is complex...

Life is complex...

• Turns out the physics make sense!
• You can't phisically have the same data in two places at the same time.
• You can copy it!
• Be pure, be immutable, make your life simple!
• People started thinking about these old ideas - functional programming?

Life is complex...

Changes!

• What about the old Actor model? Have you seen Erlang?
• What about transforming by copying and reusing immutable data, not mutating data?
• What about pure functions that we can pass and return from another function?
• What about persistent data structures?

Changes!

• OOP languages like Java got "lambda functions" and RXJava.
• Languages like Scala and F# were created - they were "functional".
• BTW F# is very cool, have you seen OCaml??
• Akka anyone?
• Use the roots of JavaScript - write functional code!

Monkeys writing books!

Also different minds, different productivity!

Also different minds, different productivity!

My message!

• My message is that functional programming is in demand!
• If you want to be concurrent, fault-tolerant, resilient - that's the easiest way.
• Even imperative languages are integrating functional idioms! Rust,C#,Java,C++,etc
• Learning some Erlang/Haskell/OCaml/Common lisp for the greater good is always a bonus!

Elixir!

• But for me Elixir is the technology for the win.
• It's Erlang, but it's also more, it has all the layers of erlang:
  • Functional : Simple sequential functional languages inside the processes
  • Concurrent : All runs in actor-like processes that run concurrently and don't share state.
  • Fault-tolerant and resilient : Comes with the great OTP behaviors that if used right lead to 99.999% availability.
  • Distributed : if a process is running on a node in Bulgaria it can just send and receive messages to and from a node in Japan.

Elixir!

• Elixir is wonderful for:
  • IOT : 1000s of devices sending streams of data to the same (distributted) server at the same time.
  • Instant Messaging and Voice Over IP : Have you heard of Discord?
  • Blockchain : For listening for new blocks and updating indexes on the chain, for managing transactions, for good integration with low level langs like Rust!
  • Even for machine learning : Check Nx/Axon, maybe we'll get rid of Python some day?!
  • Web : Rails, PHP, JEE??, Express : Why not Phoenix? We have Live View

Elixir!

Who uses Elixir?

• Pepsi - Yup the sugar bombs, they use it for their marketing software.
• Spotify - 1000s of requests in second for their sites work good for them.
• Discord - Calls, messages, many requests in real time.
• Apple - Environment and supply chain innovation (ESCI)

Who uses Elixir?

• Pinterest - Niche stuff has traffic too you know!
• Toyota - Servers for traffic updates, car sharing services
• Financial Times - Inside GraphQL APIs.
• Square Enix - User accounts for their games.

Who uses Elixir?

• Aeternity - Bockchains, smart contract management (btw also us, Eiger)
• Weedmaps - 420 man!
• Sketch - Designers use it a lot.
• Moodle - Yup, they have now MoodleNet a teacher's social network.

Who uses Elixir?

• Me!
• My friends!
• Other people!
• Why not you??

Thanks!

• Thanks to F# for the |> pipe, and thanks to OCaml for F# and Rust!
• Thanks to Haskell for making our lives interesting.
• Thanks to Math (and FMI) for showing us the way!

Thanks!

• Thanks to Ivan from the Elixir course for providing half of the content of that lecture : we did it for the opening of our course!
• Thanks to José Valim for Elixir!

Thanks and bye!

• Thanks to Pure:#code that we met!
• Thank you for spending your time with me!

Thanks and bye!