What is scala_school?

twitter/scala_school — explained in plain English

Analysis updated 2026-07-03

★ 3,696HTMLAudience · developerComplexity · 1/5Setup · easy

Mindmap

mindmap
  root((repo))
    What it does
      Teaches Scala basics
      Static lesson website
      Twitter-authored content
    Tech stack
      HTML
      Jekyll static site
      Ruby gems
    Use cases
      Learn Scala basics
      Host custom lessons
      Onboard team to Scala
    Audience
      Developers
      Learners

mindmap root((repo)) What it does Teaches Scala basics Static lesson website Twitter-authored content Tech stack HTML Jekyll static site Ruby gems Use cases Learn Scala basics Host custom lessons Onboard team to Scala Audience Developers Learners

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What do people build with it?

USE CASE 1

Read the Scala fundamentals lessons online at twitter.github.io/scala_school to learn Scala from scratch without any setup.

USE CASE 2

Clone the repository and run it locally with Jekyll to preview or adapt the lessons for your own Scala training course.

USE CASE 3

Use the lesson content to onboard a team of engineers to Scala, as Twitter originally did internally.

What is it built with?

HTMLJekyllRubyRedCloth

How does it compare?

	twitter/scala_school	tc39/proposal-temporal	mciastek/sal
Stars	3,696	3,693	3,692
Language	HTML	HTML	HTML
Setup difficulty	easy	easy	easy
Complexity	1/5	2/5	1/5
Audience	developer	developer	developer

Figures from each repo's GitHub metadata at analysis time.

How do you get it running?

Difficulty · easy Time to first run · 5min

Requires Ruby with Jekyll and RedCloth gems to build locally, the published site at twitter.github.io/scala_school works immediately with no install.

So what is it?

Scala School is a set of lessons on the Scala programming language, originally created and used by Twitter to teach Scala to its engineers. The lessons are published as a website at twitter.github.io/scala_school and cover the fundamentals of the language for people who want to learn it from the ground up. The repository contains the source files for that website. The lessons are written in a text-based markup format and turned into HTML pages using Jekyll, a tool that generates static websites from text files. The README covers only the technical side of building and publishing the site: how to install the required tools (Jekyll and RedCloth, both Ruby libraries), how to build the lesson pages locally, and how to run a local web server on port 4000 so you can preview changes as you make them. The README does not describe the lesson content itself, so it is not clear from the source file alone which specific Scala topics are covered or at what depth. Based on the project description, the scope is fundamentals, meaning the lessons are likely aimed at people who are new to Scala rather than experienced Scala developers. The published site is where the actual learning content lives. The project is maintained by Twitter and is publicly available for anyone who wants to study Scala or adapt the lessons for their own teaching purposes.

Copy-paste prompts

Prompt 1

I'm working through Twitter Scala School. Explain Scala's collections hierarchy to me as if I just finished the basics and want to understand when to use List vs Vector vs Seq.

Prompt 2

How do I build and preview the Twitter Scala School website locally? Walk me through the Ruby gem dependencies and the Jekyll commands to run a local server.

Prompt 3

I want to add a new lesson to Twitter Scala School covering Scala implicits. Show me the file format, Jekyll front matter, and a skeleton lesson structure I should follow.

Prompt 4

Based on Scala fundamentals from Twitter Scala School, give me a 5-question quiz covering type inference, case classes, and pattern matching, with answers.

Frequently asked questions