Awesome Elixir and CQRS

A curated list of awesome Elixir, Command Query Responsibility Segregation (CQRS), and event sourcing resources.

Contents

• Libraries
• Community resources
• Books
• Articles
• Presentations
• Podcasts
• Research papers
• Screencasts
• Example applications

Libraries

• Chronik - A lightweight event sourcing micro framework for Elixir.

• Commanded - Use Commanded to build your own Elixir applications following the CQRS/ES pattern. Provides support for command registration and dispatch, hosting and delegation to aggregate roots, event handling, and long running process managers.

  • Commanded audit middleware - Command auditing middleware for Commanded CQRS/ES applications using Ecto for persistence.

  • Commanded Ecto projections - Read model projections for Commanded using Ecto.

  • Commanded scheduler - Schedule one-off and recurring commands for Commanded CQRS/ES applications .

  • Commanded Swarm registry - Distributed process registry using Swarm for Commanded.

• Disco - Simple, opinionated yet flexible library to build CQRS/ES driven systems.

• Eidetic - An event sourcing library for Elixir.

• ES - Event Sourcing for Ecto and Postgresl/Dynamodb events storage.

• EventBus - Traceable, extendable and minimalist event bus implementation for Elixir with built-in event store and event watcher based on ETS.

• Eventlog - A simple event log backed by dynamodb and dynamodb streams.

• EventStore - An Elixir event store using PostgreSQL for persistence.

• Extreme - Elixir adapter for Greg Young's Event Store.

• Fable - An Elixir event sourcing library.

• Helios.Aggregate - Elixir library defining Aggregate behaviour and providing extendable facility for aggregate command pipeline.

• Incident - Event Sourcing and CQRS in Elixir abstractions.

• Maestro - An Elixir event store + CQRS library.

• Pachyderm - A virtual/immortal/durable/resilient/global actor "always exists" and "never fails".

• Perhap - Purely functional event store and service framework inspired by domain driven design and reactive architectures.

• Seven Otters - A CQRS/ES Starter Kit for the BEAM.

• TeaVent - TeaVent allows you to perform event-dispatching in a style that is a mixture of Event Sourcing and The "Elm Architecture" (TEA).

Community resources

• Awesome Domain-Driven Design - A (non language specific) curated list of Domain-Driven Design (DDD), Command Query Responsibility Segregation (CQRS), Event Sourcing, and Event Storming resources.

• DDD/CQRS/ES Discord - A Discord server for those who want to chat about domain-driven design, CQRS, event sourcing, and sometimes random things. Main channel is language and framework agnostic. Join ddd-cqrs-es Discord server

• Elixir lang Slack - This offical Elixir language Slack team includes an #eventsourcing channel for CQRS/ES and Elixir discussion. Join Elixir on Slack to get an invite.

Books

• Building Conduit - Applying CQRS/ES to an Elixir and Phoenix web app.
• Real-World Event Sourcing - Distribute, Evolve, and Scale Your Elixir Applications

Articles

• A Functional Foundation for CQRS/ES by Mathias Verraes - A CQRS architecture can be seen as a set of referentially transparent functions that model decisions and interpretation.

• Building a CQRS/ES web application in Elixir using Phoenix by Ben Smith - Case study describing how a web application was built using CQRS/ES.

• CQRS with Elixir and Phoenix by Jean-François Cloutier - Implementing the CQRS pattern in Elixir.

• DDD within Elixir/Phoenix project: Umbrella apps & Service Object by David McLeod.

• Elixir: Domain driven design with Actor Model by Naveen Negi.

• Event Sourcing in Elixir by Derek Kraan - Explore how we can use some of Elixir’s more interesting features to implement event sourcing.

• Event Sourcing in React, Redux & Elixir by Gary McAdam - How we write fast, scalable, real-time apps at Rapport.

• My First Event Sourced Application by Leif Gensert - Building an event sourced application using Commanded.

2019

• Event Sourcing With Elixir by Bruno Antunes - A multi-part blog series on event sourcing with Elixir using Commanded.

• My Journey into CQRS and Event Sourcing by Rodrigo Botti - Learning these patterns by building a patient consent example application in Elixir.

• Creating a single-node Elixir/Phoenix web app with Commanded & Postgres by Ben Moss - A blog post series to walk the reader through installing and configuring Commanded for use in a single-node Phoenix web app backed by Postgres.

2021

• Building an event-sourced game with Phoenix Liveview by Charles Desneuf - A series on building an event-sourced game in Elixir with Phoenix Liveview.

• Getting started with Elixir and EventStoreDB with the Spear gRPC client by Michael Davis.

• Tackling software complexity with the CELP stack by Cees de Groot.

2022

• Adding soft delete to a Phoenix Commanded (CQRS) API by Christian Alexander

• Supercharging our event-sourcing capabilities with Phoenix LiveView by Simone D'Avico - Building visual tools to tame event sourcing architecture complexity.

• Using CQRS in a simple Phoenix API with Commanded by Christian Alexander

Presentations

2014

• CQRS with Erlang by Bryan Hunter @ NDC 2014 - Dive into CQRS, and explore a sample implementation written in Erlang. [ slides | source code ]

2016

• Implementing CQRS on top of OTP (in Elixir) by Hubert Łępicki. [ video ]

2017

• Building CQRS/ES web applications in Elixir using Phoenix by Ben Smith.

• Event Sourcing with Commanded by Andriy Drozdyuk. [ slides | [source code](https://bitbucket.org/drozdyuk/bank-commanded-presentation-sep-25-