Why Quora Chose Python Over PHP and Other Languages

Since Facebook founder Adam D'Angelo joined the heavily PHP‑based site, I have wondered why he chose Python rather than PHP for building Quora.

Adam D'Angelo, Quora founder:

We are certain we will not use PHP. Facebook uses PHP for historical reasons, not because it is the best choice.

Choosing a programming language is crucial and changing it later can be very costly.

Python is a language both Charlie and I know well (and I now know even better). We also briefly considered C#, Java, and Scala, but Python’s main drawbacks are execution speed and lack of static type checking.

C# seemed promising and is a great language, but:

We did not want to be locked into the Microsoft stack; most engineers prefer open‑source resources, and .NET would require many secondary open‑source integrations.

We were not willing to risk using Mono (the open‑source implementation of .NET) because of its uncertain future and known issues.

We also briefly looked at OCaml and Haskell, but neither had a large ecosystem or a sufficiently good standard library for designers, data analysts, or non‑engineers.

Ultimately we decided Python was fast enough for most of our needs (critical backend code is written in C++). For type checking we rely on comprehensive unit tests, which achieve similar goals. Over the past five years Python has continued to improve, giving us confidence in its future.

Our team is happy with this choice. Early employees who previously used other languages transitioned smoothly to Python, especially those coming from PHP, after several key events:

Python 2.6 became a turning point, offering enough libraries for easy migration.

The open‑source release of Tornado allowed us to move our real‑time update service onto it.

PyPy proved usable and promised significant speed gains.

These factors reinforced our belief that Python and its ecosystem are moving in the right direction.

Charlie Cheever, Quora co‑founder:

Additional points in favor of Python:

Excellent debugging tools and mature frameworks such as Django and Pylons.

Python data structures map naturally to JavaScript, simplifying client‑server data exchange.

Python code is highly readable, which is important when many people collaborate on the site.

There is a rich ecosystem of Python libraries for mail servers, task queues, and more.

Ruby was also a reasonable alternative, sharing many advantages with Python, but both Adam and I know Python slightly better.

Original English article: https://www.quora.com/Why-did-Quora-choose-Python-for-its-development Translator: cmsl