There is no single best programming language, and anyone who tells you otherwise is selling something. The honest answer to "which should I use?" is a mix of three things: what you're building, what you already know, and which ecosystem has the libraries you'll need. Falix runs a dozen runtimes, so this guide helps you choose — and then hands you off to the guide for the one you pick.
| At a glance | |
|---|---|
| You need | Nothing yet — this is the decision before you create a server |
| Plan | Every runtime runs on free and premium |
| Time | Ten minutes |
| Ready to build? | Create your first app server |
Start with what you're building
The project usually narrows the field on its own. Here's where most people land, with the guide for each:
| I want to build… | Good picks | Start here |
|---|---|---|
| A Discord bot | Node.js (discord.js), Python (discord.py), Java (JDA), Rust (Serenity) | Your first Discord bot |
| A website or web app | Node.js, Python, PHP, Bun, Go | Your first web app |
| A REST API | Node.js/Bun, Python (FastAPI), Go | Build an Express website + API |
| A background worker / script | Python, Node.js, PHP CLI | Long-running PHP workers |
| A high-concurrency service | Go, Rust (Tokio), Elixir (OTP) | Async Rust with Tokio |
| My first-ever code | Python or JavaScript (Node.js) | Python on Falix |
Notice most rows list several options. That's real — most projects can be built well in several languages, which is why the next two questions matter more than the project type.
Then: use what you already know
If you're fluent in one language, that fluency almost always beats the "theoretically ideal" choice. You'll ship faster, debug faster, and actually finish. A perfectly-suited language you're fighting is slower than a merely-fine one you know cold.
🎯 Good to know: The single most common mistake here is picking the "impressive" language (Rust, usually) for a first project, then bouncing off the learning curve. Rust is excellent — but if you've never written it, your Discord bot will be done far sooner in the language you already speak. You can always learn the fancy one on a project where the stakes are lower.
And: does the ecosystem have what you need?
Some tasks lean hard on libraries. Scraping and data work have the richest support in Python (PyPI). JavaScript/TypeScript (Node.js, Bun) has the largest package registry overall (npm) and the best Discord and web tooling. If your project depends on a specific library, go where that library lives — that single dependency can decide the whole thing.
How each runtime actually runs on Falix
Beyond taste, one Falix-shaped difference matters when you choose: interpreted runtimes just run your source, while compiled ones need a build — either a long compile on the server or a binary you produce first. Here's the whole catalogue:
| Runtime | Build model on Falix | TypeScript? | Best known for | Guide |
|---|---|---|---|---|
| Node.js | Runs node index.js; auto npm install |
Needs a build recipe | Bots, web, the biggest ecosystem | nodejs |
| Bun | Runs bun run; auto bun install |
Native | A fast, Node-compatible runtime | bun |
| Python | Runs python app.py; installs requirements.txt |
— | Bots, scripting, data, web | python |
| PHP | CLI / Composer / Web Server variants | — | Websites and scripts | php |
| Go | Runs a prebuilt app binary you build first |
— | Fast services, APIs, tiny footprints | go |
| Rust | cargo run --release compiles on start (slow first) |
— | Maximum performance, systems work | rust |
| Java | Runs a fat app.jar you build and upload |
— | Large apps, JDA bots | java |
| C# / .NET | dotnet restore + dotnet run on start |
— | The .NET ecosystem, workers | dotnet-console-apps |
| Deno | ./deno run app.js; permission flags gated |
Native | Permissionless TS scripts | deno-on-falix-deep |
| Dart | dart pub get; dart run; needs a package layout |
— | Dart/Flutter-adjacent backends | more-runtimes |
| Elixir | mix run --no-halt; needs a Mix project |
— | Always-up, concurrent systems | elixir-otp-basics |
| Lua (Luvit) | ./luvit app.lua |
— | Lightweight async Lua | lua-luvit-deep |
Two honest gotchas hide in that table:
- TypeScript runs natively on Bun and Deno. On Node.js it needs a build-on-install recipe (a bare
.tsentry file won't run) — see Node.js on Falix. - Deno is secure by default, so a Deno web server needs permission flags that require editing the startup command — a premium feature. If you want a web app on the free plan, Node, Bun, Python, PHP, and Go all serve out of the box. The full story is in Deno on Falix in depth.
No favourites — really
Every runtime in that table is a good choice for the right project, and Falix runs them all the same way underneath: your code in /home/container, one public port from SERVER_PORT, dependencies that install on start (or a build you provide). The worst language is the one you'll abandon halfway. Pick the one that gets your project shipped, open its guide, and go.