Stack directory
What real companies actually run, and why they chose it.
Airbnb
Airbnb's core booking platform, internally nicknamed Monorail, is a large Ruby on Rails application that the company has invested heavily i…
Amazon
Amazon originally built standardized infrastructure to run its own retail business more efficiently; that internal infrastructure, includin…
Basecamp
Basecamp (formerly 37signals) is the company that built and open-sourced Ruby on Rails in the first place, extracting it from its own produ…
Discord
Discord uses Elixir, which runs on the same virtual machine as Erlang, to power the real-time messaging gateway that keeps millions of conc…
Dropbox
Dropbox leaned heavily on Python across its backend and desktop client for years, later rewriting performance-critical parts of its sync en…
Etsy
Etsy built its marketplace on PHP and became well known in the engineering community for a culture of shipping small, frequent changes safe…
GitHub
GitHub has run on Ruby on Rails since it started, and is frequently cited as one of the largest and longest-lived Rails applications in the…
Google created the Go programming language and Kubernetes, and its early internal papers on MapReduce and Bigtable directly inspired the op…
Instagram was built fast, on Python and Django, by a small founding team that valued speed of iteration over almost anything else in the ap…
LinkedIn built and open-sourced Apache Kafka to handle its internal streams of activity data, later followed by the related stream-processi…
Meta (Facebook)
Facebook grew up on PHP, and rather than rewrite everything, the company built its own compiler and later a new language, Hack, plus the HH…
Netflix
Netflix's backend is a large ecosystem of Java-based microservices, supported by resilience tools like Hystrix, Eureka and Chaos Monkey tha…
Pinterest started as a small Python and Django application, and its early engineering writing is well known for documenting how the team sc…
Reddit was very briefly written in Common Lisp before the founders rewrote it in Python within its first few months in 2005; Python has bee…
Shopify
Shopify runs one of the largest Ruby on Rails deployments anywhere, handling huge, spiky traffic during major sales events on the same fram…
Slack
Slack was originally built primarily in PHP, and as it scaled the team began migrating performance-sensitive parts of the backend toward Ha…
Spotify
Spotify runs the bulk of its backend services on the JVM using Java, while relying on Python separately for data science and machine learni…
Stripe
Stripe's core API and much of its backend are written in Ruby, and the company later built and open-sourced Sorbet, a type checker that add…
Twitter (X)
Twitter started on Ruby on Rails during its "fail whale" era, then moved much of its backend onto the JVM using Scala as it grew, while als…