Phoenix

Phoenix (Elixir) provides real-time scalability (millions of connections). v1.7 + LiveView allows building rich SPAs without writing JavaScript.

When to Use

• Real-time: Chat apps, live dashboards (Channels).
• High Concurrency: Leveraging the BEAM VM (Erlang).
• Low JS: LiveView handles the UI state on the server.

Core Concepts

LiveView

Server-rendered HTML that updates over WebSockets. "The server is the state source".

Ecto

The database wrapper. Using Changeset for validation.

PubSub

Built-in, distributed publish-subscribe system.

Best Practices (2025)

Do:

• Use Verified Routes: ~p"/users/#{@user}" ensures compile-time link safety.
• Use Tailwind: Default in 1.7.
• Use Function Components: HEEx templates with declarative assigns.

Don't:

• Don't use SPA unless needed: LiveView covers 95% of use cases.

References

• Phoenix Documentation