Elixir & Phoenix

Why Elixir

Most backend technologies force you to choose. Fast or maintainable. Concurrent or simple. Reliable or cheap to run. Elixir doesn’t make you choose.

Elixir runs on the Erlang VM (BEAM) — the same technology that powers telecom systems handling millions of concurrent connections. Ericsson built it in the 1980s for phone switches that couldn’t go down. Thirty years later, that same reliability runs WhatsApp, Discord, and financial trading systems. When we need a backend that handles real-time updates, massive concurrency, and genuine fault tolerance, Elixir is our first choice.

The language itself is a joy. Pattern matching makes complex logic readable. Immutable data structures eliminate entire categories of bugs. The pipe operator chains transformations elegantly. Code reviews become discussions about business logic, not defensive programming. Developers who learn Elixir rarely want to go back.

Phoenix Framework

Phoenix gives you Rails-like productivity with Elixir’s performance. The framework handles the boring stuff — routing, templates, database migrations — so you focus on building features. But unlike Rails, Phoenix doesn’t fall over when traffic spikes.

LiveView changed everything. You can build reactive, real-time UIs without writing JavaScript. The server tracks state and pushes diffs over WebSockets. Forms validate instantly. Dashboards update in real time. All in Elixir, all type-safe, all with the same debugging tools. For many applications, you don’t need a separate frontend framework at all.

Channels make real-time features trivial. Chat? A few dozen lines. Collaborative editing? Straightforward. Live notifications? Built-in. We’ve shipped real-time features in days that would take weeks in other stacks.

What We Build With It

We reach for Elixir when systems need to stay up and stay fast. Real-time collaboration tools where users see each other’s changes instantly. High-traffic APIs that handle Black Friday without provisioning extra servers. IoT backends ingesting thousands of sensor readings per second. Financial systems where downtime costs money and data loss costs more.

Chat and messaging platforms are a natural fit. Each conversation can be its own process, isolated from others. One misbehaving user can’t crash the system. Presence tracking — knowing who’s online — comes out of the box. We’ve built platforms handling millions of messages without breaking a sweat.

Healthcare applications benefit from Elixir’s reliability. When you’re tracking patient data or coordinating care, you need the system to work. Elixir’s supervisor trees restart failed processes automatically. Problems stay contained. Logs capture everything. Auditors love it.

Our Experience

We’ve shipped production Elixir systems handling thousands of concurrent users. We know the ecosystem inside and out. Ecto for database work. Oban for background jobs. Broadway for data pipelines. ExUnit for testing. We’ve built umbrella apps, designed supervision trees, and debugged production systems under load.

Our patterns have evolved through real projects. Contexts for bounded domains. Service modules for complex business logic. Changesets for validation that tells users what went wrong. We write the kind of Elixir code that makes the next developer’s job easier.

When to Use Elixir

Choose Elixir when you need real-time features, high concurrency, or systems that can’t afford downtime. When you’re building something that will scale to thousands of simultaneous users. When you want a codebase that stays maintainable as it grows.

Skip Elixir if you’re building a simple CRUD app that will never need real-time features. If your team only knows JavaScript and doesn’t have time to learn. If you need CPU-heavy computation — Elixir is concurrent, not fast at number crunching.

Common Challenges

Deployment used to be tricky. Releases solved that. We use mix release with Docker for consistent, reproducible deployments. Health checks, graceful shutdowns, and rolling updates work out of the box.

The learning curve is real. Functional programming feels strange at first. Pattern matching clicks after a few weeks. OTP concepts take longer. We’ve onboarded plenty of developers — the investment pays off within a month.

Finding Elixir developers is harder than finding JavaScript developers. But the ones you find tend to be experienced and thoughtful. They chose Elixir for a reason. We’ve never regretted hiring for Elixir skills.

Debugging distributed systems requires different tools. Observer shows you what’s happening across nodes. Telemetry captures metrics. We instrument everything from the start. When something goes wrong at 3 AM, we know exactly where to look.