Jack Marchant

Principal Software Engineer @ Deputy

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Lonestar ElixirConf 2019 Highlights

Last week was Lonestar ElixirConf 2019 held in Austin, Texas. The conference ran over 2 days and was the first Elixir conference I had been to.

In this article, I will recap some of my personal highlights from the conference, including my thoughts about some of the talks. Before I get into that however, I’d just like to say upfront how great it was to be in a room full of Elixir enthusiasts of all levels of experience. Some people were there to find a way to help sell their organisations on Elixir, and others had helpful insights into running Elixir in production. The conference was really well organised and the schedule allowed for plenty of breaks between all of the awesome talks.


Opening the conference was a keynote delivered by Justin Schneck, author of Nerves Project. Embedded systems are really taking off in the Elixir community and Justin made it clear to see why, as he showed how easy it was to get started with Nerves, and how to use NervesHub, which is a tool that allows you to manage firmware updates to physical devices, making deployments easy and secure.

While I haven’t done any work with Nerves yet it did make me interested to find a side project I could work on to give it a try.

Most of my work at Vamp is on the web so it’s unlikely there will be a need for embedded systems, but it speaks to the flexibility and uniqueness of Elixir that something like Nerves can allow anyone to get started working with real devices.

Distributed State Management

A hot topic in the Elixir community revolves around distributed state management and common pitfalls, paired with potential solution.

We all know Elixir is great at concurrency and provides a programming model that makes it much simpler to think about but what makes Elixir really shine is when you add extra nodes as the application scales.

This was the subject of the talks from the first morning of the conference with both describing the complexities involved in great detail.

The talks didn’t really offer a specific solution (although they mentioned the likes of Swarm - a distributed process registry) but instead referred to trade offs that anyone facing these problems will have to make, most notably CAP theorem and the balancing scale of Consistency and Availability, given that there will always be a Network Partition in a distributed system.

I really enjoyed this section, so it was a great start to the conference.


With the recent split of the Ecto library into two parts: ecto, and ecto_sql in an effort to make it more visible to developers that Ecto can be used without a database, it was only fitting that there would be a few talks about Ecto. I particularly enjoyed Greg Vaughn's "Ecto without a DB", in which Greg presented practical examples of using Ecto Changesets to validate external data, mapping to structs and applying certain actions to achieve the same validation you would expect with Repo callbacks such as insert/1 and update/1.

Generally, this approach seemed to highlight the fact that having data structures in your application instead of ad-hoc maps in domain logic makes handling errors easier and prevents messy code.

The Business Case for Elixir

Brian Cardarella (CEO of Dockyard) presented his views on the business case for Elixir, specifically referring to 4 main points (paraphrasing):

Phoenix LiveView

Although it had already been announced (but not released yet), Phoenix LiveView was presented to the audience at Lonestar ElixirConf with a promise from Chris McCord to be released as early as the end of the month but at least in the coming months.

Chris spoke about the motivations for building LiveView and stressed the goal of delaying the inevitable single page application path for as long as possible. How long that is will be determined after release when people have had time to use it.

I am personally quite optimistic about it and although I'm happy to keep writing JavaScript on the frontend whenever I need to, it will make building prototype apps to showcase Elixir's real-time capabilities much easier.

The conceptual programming model for LiveView is very similar to that of React and other JavaScript libraries, in that each component has a parent-child relationship, with the default behaviour that if a child component fails, it can be restarted back to its last known state. It is in this way they behave like children in a supervision tree. The similarities between frontend view libraries like React and Elixir/Erlang supervision Trees is a topic I have written about before.

Erlang Ecosystem Foundation

In Jose Valim’s keynote, which capped off the presentations for the conference, he introduced the EEF (Erlang Ecosystem Foundation) as a new organisation run for the community of Elixir and Erlang (and any other languages running on the BEAM (the virtual machine on which Erlang runs). It’s goal is to procure funding for projects within the community to help improve the tooling that surrounds Erlang.


Jose also presented Broadway, a new library that was released only a week ago. Broadway is an extension of GenStage, which models producers and consumers as stages in a pipeline that ingests and processes data.

The new library is meant to allow for distributed pipelines to operate in parallel.

Rather than adding these features into the Elixir language, the core team prefers to keep the standard API small and closely matching with Erlang.

Wrapping up

It’s an exciting time to be an Elixir developer as the language has definitely matured over the years without making any drastic changes. In the years to come I hope there will be more success stories from companies using Elixir along with promoting the success coming from developer productivity and happiness building Elixir applications and scaling them.

Lonestar ElixirConf 2019 seemed to be very successful and I certainly enjoyed being there.

I would like to thank Vamp for sponsoring me to make the journey from Australia and hope to see more Australian companies take part in the global Elixir community.

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broken windows

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lonestar elixir 2019

Last week was Lonestar ElixirConf 2019 held in Austin, Texas. The conference ran over 2 days and was the first Elixir conference I had been to.

genserver async concurrent tasks

In most cases I have found inter-process communication to be an unnecessary overhead for the work I have been doing. Although Elixir is known for this (along with Erlang), it really depends on what you’re trying to achieve and processes shouldn’t be spawned just for the fun of it. I have recently come across a scenario where I thought having a separate process be responsible for performing concurrent and asynchronous jobs would be the best way to approach the problem. In this article I will explain the problem and the solution.

best practices third party integrations

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offset cursor pagination

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Recently, I've been writing a tonne of Elixir code, some Phoenix websites and a few other small Elixir applications. One thing that was bugging me every time I would create a new project is that I would want to add Docker to it either straight away because I knew there would be a dependency on Redis or Postgres etc, or halfway through a project and it would really slow down the speed at which I could hack something together.

working with tasks

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understanding concurrency

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composing ecto queries

Ecto is an Elixir library, which allows you to define schemas that map to database tables. It's a super light weight ORM, (Object-Relational Mapper) that allows you to define structs to represent data.

streaming datasets

We often think about Streaming as being the way we watch multimedia content such as video/audio. We press play and the content is bufferred and starts sending data over the wire. The client receiving the data will handle those packets and show the content, while at the same time requesting more data. Streaming has allowed us to consume large media content types such as tv shows or movies over the internet.

elixir queues

A Queue is a collection data structure, which uses the FIFO (First In, First Out) method. This means that when you add items to a queue, often called enqueuing, the item takes its place at the end of the queue. When you dequeue an item, we remove the item from the front of the queue.

composing plugs

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elixir supervision trees

A Supervision Tree in Elixir has quite a number of parallels to how developers using React think about a component tree. In this article I will attempt to describe parallel concepts between the two - and if you've used React and are interested in functional programming, it might prompt you to take a look at Elixir.

surviving tech debt

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pattern matching elixir

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write unit tests

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