Day 16 – Deploying ML Models with Flask & FastAPI


Introduction

Building and training machine learning models is only part of the journey. Deploying ML models to production enables real-world applications such as recommendation systems, spam detection, and predictive analytics.

At CuriosityTech.in (Nagpur, Wardha Road, Gajanan Nagar), we emphasize hands-on deployment training. By integrating Flask and FastAPI, ML engineers can serve models as APIs, making them accessible to web and mobile applications.


1. Understanding Model Deployment

Definition: Deployment is the process of making a trained ML model available for real-time or batch predictions in production.

Benefits of Deployment:

  • Real-time predictions for users or systems
  • Integration with web and mobile applications
  • Continuous monitoring and updates
  • Scalable and reproducible solutions

CuriosityTech Insight: Many beginners build models but struggle with deployment. Deployment is mandatory for ML engineers who want to create end-to-end solutions.


2. Deployment Options

Deployment TypeDescriptionUse Case
Local DeploymentRun on local machineTesting and development
Cloud DeploymentAWS, GCP, AzureScalable production applications
Dockerized DeploymentContainerize modelsReproducibility and scalability
MicroservicesDeploy as APIIntegrate multiple models into applications

3. Flask vs FastAPI

FeatureFlaskFastAPI
SpeedModerateHigh (async support)
API DocumentationManualAutomatic Swagger UI
Learning CurveBeginner-friendlySlightly advanced
Use CaseSmall-scale projectsHigh-performance APIs, modern apps

At CuriosityTech.in, learners often start with Flask for hands-on practice and then move to FastAPI for scalable and performant APIs.


4. Stepwise Deployment Workflow

Diagram Description: Trained ML Model → Save as Pickle/Joblib → Flask/FastAPI App → API Endpoint → Client Request → Prediction Response

Workflow Stages:

  1. Train and Save Model: Serialize using Pickle or Joblib
  2. Create Flask/FastAPI App: Define API routes for prediction
  3. Load Model in App: Load serialized model for inference
  4. Accept Input Data: Receive JSON or form data from client
  5. Return Prediction: Send JSON response with prediction results
  6. Optional: Implement logging, monitoring, and validation

5. Example: Deploying a Spam Detection Model

  • Step 1: Save the Model
    • import joblib
    • joblib.dump(model, ‘spam_model.pkl’)
  • Step 2: Create Flask App
    • from flask import Flask, request, jsonify
    • import joblib
    • app = Flask(__name__)
    • model = joblib.load(‘spam_model.pkl’)
    • @app.route(‘/predict’, methods=[‘POST’])
    • def predict():
    • data = request.get_json()
    • message = data[‘message’]
    • vect = vectorizer.transform([message])
    • prediction = model.predict(vect)[0]
    • return jsonify({‘prediction’: prediction})
    • if __name__ == ‘__main__’:
    • app.run(debug=True)
  • Step 3: Testing API
    • Use Postman or curl to send POST requests
    • Receive real-time predictions

Practical Insight: Riya at CuriosityTech Park deploys a spam detection API, demonstrating how users can access model predictions via a web interface.


6. FastAPI Deployment Advantages

  • Asynchronous Endpoints: Handle multiple requests concurrently
  • Automatic Documentation: Swagger UI and ReDoc
  • Input Validation: Pydantic models ensure structured data

FastAPI Example Snippet:

from fastapi import FastAPI

from pydantic import BaseModel

import joblib

app = FastAPI()

model = joblib.load(‘spam_model.pkl’)

class Message(BaseModel):

    message: str

@app.post(“/predict/”)

def predict_spam(data: Message):

    vect = vectorizer.transform([data.message])

    prediction = model.predict(vect)[0]

    return {“prediction”: prediction}

Students at CuriosityTech.in appreciate automatic documentation, which allows stakeholders to test APIs without writing additional code.


7. Deployment Best Practices

  • Version Control Models: Track multiple versions using MLflow
  • Input Validation: Prevent errors and malicious input
  • Logging & Monitoring: Record requests and responses for analysis
  • Dockerize Applications: Ensure reproducibility and easier scaling
  • Continuous Integration (CI/CD): Automate deployment pipelines

Scenario Storytelling: Arjun implements a Dockerized FastAPI deployment of a recommendation system. The model serves thousands of requests per day, and automatic logging helps identify when retraining is needed.


8. Real-World Applications

ApplicationDeployment TypeExample
Spam DetectionFlask APIWeb and mobile apps
Sentiment AnalysisFastAPI + DockerSocial media analytics
Image RecognitionCloud APIHealthcare imaging
Predictive MaintenanceMicroservicesIoT sensor data
Recommendation SystemsFlask/FastAPIE-commerce and streaming

9. Key Takeaways

  • Deployment makes ML models accessible and actionable
  • Flask is easy for beginners, FastAPI is ideal for performance and scalability
  • Automation, validation, logging, and monitoring are mandatory for production-ready systems
  • Hands-on practice bridges the gap between training models and creating usable ML services

CuriosityTech.in trains learners in end-to-end ML model deployment, preparing them for real-world applications.


Conclusion

Deploying ML models with Flask and FastAPI equips ML engineers to turn models into usable services, accessible by web or mobile applications. Mastery of deployment ensures:

  • Scalable production solutions
  • Real-time predictions for users
  • Smooth integration with enterprise systems

Contact CuriosityTech.in at +91-9860555369 or contact@curiositytech.in to learn hands-on deployment and API integration for ML projects.


Leave a Comment

Your email address will not be published. Required fields are marked *