[Python] Is it a best practice to send confirmation emails inside a Stripe...

I'm working on a Flask web application where users can purchase a subscription via Stripe Checkout. I've implemented a webhook endpoint to handle the checkout.session.completed event.

Here’s what currently happens inside the webhook handler:

1. 
   Stripe sends the checkout.session.completed event.
   
   
2. 
   I verify the event signature.
   
   
3. 
   I update the user's subscription status in the database.
   
   
4. 
   I send a confirmation email (e.g., "Your subscription is now active").
   

The relevant logic is synchronous (the email is sent before responding 200 OK to Stripe).

Here is a simple code snippet:

try:
event = stripe.Webhook.construct_event(payload, sig_header, STRIPE_WEBHOOK_SECRET)
except stripe.error.SignatureVerificationError:
return 'Invalid signature', 400

if event['type'] == 'checkout.session.completed':
session = event['data']['object']
user = User.query.filter_by(email=session['customer_email']).first()
user.is_subscribed = True
db.session.commit()

# Send confirmation email
send_email(
to=user.email,
subject='Subscription Confirmed',
body='Your subscription is now active.'
)

return '', 200


My questions: Is it considered efficient and best practice to send transactional emails (like confirmations) inside the webhook handler?

Should I offload email sending to a background job (e.g., Celery or RQ) and just respond to Stripe immediately to avoid webhook timeouts or retry issues?

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