Even though I'm a backend developer, my main programming language is JavaScript, and the reason is simple:

JavaScript, like English, has many inconsistencies, historical quirks, and flaws, but it is EVERYWHERE.

Atwood's law: "Any application that can be written in JavaScript, will eventually be written in JavaScript".

There is a JavaScript runtime environment on almost every phone and computer—your browser.

You can’t run away from it - One of my friends hates English and uses it only because he needs it for his PhD. Same with JS. It’s everywhere.

Personal Opinion: I didn’t struggle much because of my choice of main programming language. Other issues are more challenging.

Why Use JavaScript on the Backend?

• Unified Language Stack (Full-Stack Development) - You don’t need another programming language—no context switching.
• An asynchronous, single-thread, Non-Blocking I/O Model
• Asynchronous means that tasks can run independently of the main program flow
• A single-threaded system means the program can only execute one task at a time
• Input/Output: Great for I/O tasks like Network requests, Data queries, API calls
• Scale applications horizontally i.e., Use multiple servers
• Fast Execution Speed

When to avoid it:

• Scale applications vertically AKA CPU-intensive processes.

Tip: Match your language choice to your goals

Don’t use Javascript to develop an AAA video game

Technically, you could achieve this using worker threads or child processes, but this is not Node's default or ideal use case.

Next topic: Monoliths vs Microservices. Stay tuned!