What is the best way to run long running task, but that returns response to a client in the same session?

[martinenkoEduard]

I am not very familliar with flask.
I need to run long running tasks (mostly requests to REST API)
But for simplicity I want to return response in the same sessions.
So without queques like celery and rabbitMQ.

What is the proper way to do this.

For instance:

from compreface import CompreFace
from compreface.service import RecognitionService
from compreface.service import DetectionService
from compreface.collections import FaceCollection
from compreface.collections.face_collections import Subjects


from pymilvus import (
    connections,
    utility,
    FieldSchema,
    CollectionSchema,
    DataType,
    Collection,
)
from pymilvus import utility

from pprint import pprint
import numpy
import os

from flask import Flask


app = Flask(__name__)
@app.route('/')
def hello():
    connections.connect("default", host="localhost", port="19530")
    DOMAIN: str = 'http://localhost'
    PORT: str = '8000'
    API_KEY: str = '00000000-0000-0000-0000-000000000002'
    DETECTION_API_KEY = '00000000-0000-0000-0000-000000000003'
    image_path: str = "test.jpg"

    compre_face: CompreFace = CompreFace(DOMAIN, PORT, 
    options={
        "face_plugins": "calculator"})
    detection: DetectionService = compre_face.init_face_detection(DETECTION_API_KEY)
    response = detection.detect(image_path)
    embedings = response['result'][0]['embedding']

    collection = Collection("photos")
    collection.load()

    search_param = {
            "data": [embedings],
            "anns_field": "embeddings",
            "param": {"metric_type": "L2", "params": {}},
            "limit": 5}
    results = collection.search(**search_param)
    return results

How do I improve this?
considering that
collection.search(**search_param) and detection.detect(image_path) can take a while.

And where do I need to put connection to databases and so on?
After app = Flask(name)
or
inside

@app.route('/')
def hello():