Ruby vs Elixir
Side-by-side comparison of Ruby and Elixir — syntax, concurrency, and trade-offs.
Both Ruby and Elixir prioritize developer happiness, but they take fundamentally different approaches to concurrency. Ruby is object-oriented and interpreted; Elixir is functional and runs on the Erlang VM.
| Feature | Ruby | Elixir |
|---|---|---|
| Paradigm | Object-oriented | Functional |
| Typing | Dynamic, interpreted | Dynamic, compiled to BEAM |
| Variable | x = 42 (mutable) |
x = 42 (immutable rebinding) |
| Function | def add(a, b) = a + b |
def add(a, b), do: a + b |
| Array | nums = [1, 2, 3] |
nums = [1, 2, 3] (linked list) |
| Map | m = { "a" => 1 } |
m = %{a: 1} |
| Struct | User = Struct.new(:name) |
%User{name: "Ada"} |
| Error handling | begin/rescue |
try/rescue + pattern matching |
| Pattern match | Limited (case with ===) |
Pervasive ({a, b} = {1, 2}) |
| Loop | 5.times { |i| } |
Recursion / Enum.each |
| String interp | "Hello #{name}" |
"Hello #{name}" |
| Concurrency | Threads (GIL-limited) | Actor model (millions of processes) |
| Module | require / gems |
use / mix deps |
| Testing | rspec |
ExUnit (built-in) |
| Hot reload | No | Yes (BEAM) |
| Fault tolerance | Application-level | Supervisor trees built-in |
Concurrency Comparison
Ruby — Thread + Queue
queue = Queue.new
Thread.new { queue.push(42) }
val = queue.pop
Elixir — Actor Model / Task
task = Task.async(fn -> 42 end)
val = Task.await(task)
Elixir processes are isolated, lightweight (~300 bytes), and killed independently. Supervisors automatically restart failed processes. Ruby threads share memory and are constrained by the GIL for CPU-bound work.
When to Choose Ruby
- You want the Rails ecosystem and convention-over-configuration
- Your app is CRUD-heavy with moderate traffic
- Your team is already proficient in Ruby
- You need rich metaprogramming capabilities
When to Choose Elixir
- You need massive concurrency (WebSockets, real-time, chat)
- Fault tolerance and hot code upgrades matter
- You want functional programming with pattern matching
- You’re building distributed systems that must stay up