Workflow engines sound complicated, but they don’t have to be. I’ll show you how Reactor uses a dead simple graph algorithm (find nodes with no dependencies, run them, remove them, repeat) to build something genuinely useful. We’ll dig into how this basic approach, combined with OTP, gives you concurrent execution with concurrency limits, automatic retries, compensation when things go wrong (and they will), and the ability to compose workflows inside each other. You’ll see how we made the simple cases easy without making the complex cases impossible.

Bio: James Harton is a Principal Engineer at Alembic, creator of Beam Bots, and Ash core team member. He is the author of Reactor, Ash Authentication, and many other libraries in the Elixir ecosystem. Based in New Zealand, James has been building with Elixir for over a decade and has a particular interest in embedded systems and Nerves. When not writing Elixir, he’s probably soldering something.

James Harton is a Principal Engineer at Alembic, creator of Beam Bots, and Ash core team member. He is the author of Reactor, Ash Authentication, and many other libraries in the Elixir ecosystem. Based in New Zealand, James has been building with Elixir for over a decade and has a particular interest in embedded systems and Nerves. When not writing Elixir, he’s probably soldering something.