Ask HN: Would you use Python as the main lang in a potentially large project?

tl;dr Would you advocate for using Python as the main language in a potentially large-scale project and long running standalone project (not a library)? Such as if you are a startup aiming to build a sustainable SaaS that becomes your full time occupation, or for enterprise projects?

I've been using Python for over 4 years from writing web applications for enterprise to startups in Django and Flask, and to RF test frameworks leveraging GNURadio. Python was a suitable choice for many problems I have encountered as because the ecosystem is extremely broad and it is very easy to get started, not just because the language is simple, but because of the popular "battery-included" frameworks. This means I can deliver value must faster from the beginning.

But having worked in a company which develops many different production systems developed over a period of 10 years, some running on platforms such as Debian etch, I can't help to think that had an enterprise language and ecosystem such as Java or .NET been chosen, maintenance and new features would have been significantly easier, because you hit performance issues much later and understanding legacy code bases are easier even if poorly written because of the static typing, and migration between different runtime versions is first-class.

I see Python (or similarly, Ruby) being used at large-scale at consumer-facing businesses such as Reddit, Digg, Uber, Dropbox, etc. but many eventually integrate to a JVM based language into their production system.

Would you advocate for using Python as the main language in a potentially large-scale project and long running standalone project? For people who have had the experience, it is worth using Python at the beginning and bearing the cost of adding another language and ecosystem in the mix when to support/replace Python when you hit scaling issues?

In your case, if you are just planning to de a web API with the majority of the workload being I/O (such as hitting other APIs), then node.js (outperform Python and Ruby out of the box in this case IMO). Otherwise, Python is a more versatile choice. All 3 are relatively easy to start, but given you like Rails, which is big on convention over configuration, the closest you'll get, that has a large community is Django, and a Node.JS counterpart would be sails.js. The biggest difference is in the languages itself, all 3 have some distinct differences in design.

But all 3 suffer from the same issues that dynamic languages have, and weren't designed for enterprise. Node.js is also being added to existing enterprise applications, but normally for anything web facing.

EDIT: Add opinion relating back to main question.

True, I've been using type notations with all my Python 3.5+ projects (and works very well with PyCharm), though noting that this is only a recent addition, available (officially) for very recent Python releases and is not enforced out of the box. And yes, delivering on the project is critical, especially for startups at the very beginning where you're still trying to find product-market fit so sudden production changes need to be swift.

> Python as the main language in a potentially large-scale project

This is the flaw in your thinking, the word Potentially. Good engineering means you worry about actual problems and not potential problems (within reason ofc). Your actual problem is that you haven't written the web application, so you do that first. For doing that, Python is an excellent choice.

"But what about web-scale?" Well, chances are your product will fail for some reason and never become successful therefore thinking about scaling problems now is a waste of time. In my experience, scaling problems comes much later than most people think. I've worked on an interactive site in Django that served 60k visitors per day without problems. It was the database that gave us the most performance problems not Python.

>I've been using Python for over 4 years from writing web applications for enterprise to startups in Django and Flask

He has used python to write web applications.