Python (Flask) MongoDB Speed Issue - mongodb

Question

I have a big speed problem on my website using Flask/MongoDB as backend. A basic request (get 1 user for example) takes about 4 sec to respond.
Here is the python code :
#users_apis.route('/profile/<string:user_id>',methods= ['GET','PUT','DELETE'])
#auth_token_required
def profile(user_id):
if request.method == "GET":
avatar = ''
if user_id == str(current_user.id):
if(current_user.birthday):
age = (date.today().year - current_user.birthday.year)
else:
age = ''
return make_response(jsonify({
"id" : str(current_user.id),
"username" : current_user.username,
"email" : current_user.email,
"first_name": current_user.first_name,
"last_name" : current_user.last_name,
"age" : age,
"birthday" : current_user.birthday,
"gender" : current_user.gender,
"city" : current_user.city,
"country" : current_user.country,
"languages" : current_user.languages,
"description" : current_user.description,
"phone_number" : current_user.phone_number,
"countries_visited" : current_user.countries_visited,
"countries_to_visit" : current_user.countries_to_visit,
"zip_code" : str(current_user.zip_code),
"address" : current_user.address,
"pictures" : current_user.pictures,
"avatar" : "",
"interests" : current_user.interests,
"messages" : current_user.messages,
"invitations" : current_user.invitations,
"events" : current_user.events
}), 200)
And my mongodb database is build like this :
The selected user is nearly empty (has no friends, no events, no pictures...).
class BaseUser(db.Document, UserMixin):
username = db.StringField(max_length=64, unique=True, required=True)
email = db.EmailField(unique=True, required=True)
password = db.StringField(max_length=255, required=True)
active = db.BooleanField(default=True)
joined_on = db.DateTimeField(default=datetime.now())
roles = db.ListField(db.ReferenceField(Role), default=[])
class User(BaseUser)
# Identity
first_name = db.StringField(max_length=255)
last_name = db.StringField(max_length=255)
birthday = db.DateTimeField()
gender = db.StringField(max_length=1,choices=GENDER,default='N')
# Coordinates
address = db.StringField(max_length=255)
zip_code = db.IntField()
city = db.StringField(max_length=64)
region = db.StringField(max_length=64)
country = db.StringField(max_length=32)
phone_number = db.StringField(max_length=18)
# Community
description = db.StringField(max_length=1000)
activities = db.StringField(max_length=1000)
languages = db.ListField(db.StringField(max_length=32))
countries_visited = db.ListField(db.StringField(max_length=32))
countries_to_visit = db.ListField(db.StringField(max_length=32))
interests = db.ListField(db.ReferenceField('Tags'))
friends = db.ListField(db.ReferenceField('User'))
friend_requests = db.ListField(db.ReferenceField('User'))
pictures = db.ListField(db.ReferenceField('Picture'))
events = db.ListField(db.ReferenceField('Event'))
messages = db.ListField(db.ReferenceField('PrivateMessage'))
invitations = db.ListField(db.ReferenceField('Invitation'))
email_validated = db.BooleanField(default=False)
validation_date = db.DateTimeField()
I have a debian serveur with 6Go Ram and 1 vcore, 2,4GHz.
When I check the log for the mongoDB I don't see request that takes more then 378ms (for a search request)
If I use TOP during a request on my server:
I see for 1 sec a 97% CPU use for Python during the request.
When I check the python server output :
I see 4 second between the Option request and the Get Request.

Answer 1

I finally managed to "fix" my issue.
It seems all the problem was due to the #auth_token_required.
Each request done by the front end to the back end with the "headers.append('Authentication-Token',currentUser.token);" created a huge delay.
I replaced #auth_token_required by #login_required.
I m now using cookies.
Hope it helps someone.