Have you had experience developing web applications using pure Flask without additional extensions?

Yes, experience in developing web applications using pure Flask without additional extensions is quite possible. Flask is a minimalist web framework that provides basic tools for routing, request handling, and template rendering.

Example of a simple application on pure Flask:

from flask import Flask, request, render_template_string

app = Flask(__name__)

@app.route('/')
def index():
    return 'Hello, Flask!'

if __name__ == '__main__':
    app.run(debug=True)

Without extensions, you implement additional functions yourself, such as working with databases, authentication, etc., which gives full control over the application's architecture.