What is Erlang?

Erlang is a programming language created for building systems that need to run nonstop, like phone networks. It focuses on handling many tasks at once and keeping the system alive even when parts fail.

Let's break it down

  • Programming language: a set of rules and symbols that tell a computer what to do.
  • Created for building systems: it was designed to help developers make large software projects.
  • Run nonstop: the software can keep working 24/7 without stopping.
  • Phone networks: the original use was for telephone switches that connect calls.
  • Handling many tasks at once: it can manage thousands of small jobs (processes) simultaneously.
  • Keeping the system alive: if one part crashes, the rest keep working; the language helps recover automatically.

Why does it matter?

If you need software that must never go down-like messaging apps, online banking, or IoT back-ends-Erlang gives you tools to build that reliability and scalability without huge engineering effort.

Where is it used?

  • Telecom switches and signaling systems (e.g., Ericsson, Nokia).
  • Real-time chat and messaging platforms such as WhatsApp.
  • Distributed databases and message brokers like CouchDB and RabbitMQ.
  • IoT device management platforms that require high availability.

Good things about it

  • Fault tolerance: crashes are isolated, so the whole system stays up.
  • Massive concurrency: can run millions of lightweight processes efficiently.
  • Hot code swapping: update code while the system is running without downtime.
  • Built-in distribution: nodes can easily talk to each other across a network.
  • Simple, immutable data: reduces bugs caused by unexpected state changes.

Not-so-good things

  • Steep learning curve: its syntax and functional style are unfamiliar to many developers.
  • Limited ecosystem: fewer libraries and tools compared to mainstream languages like JavaScript or Python.
  • Performance for CPU-heavy tasks: not as fast as compiled languages like C or Rust for intensive calculations.
  • Smaller talent pool: harder to hire experienced Erlang engineers.