README.md

metadata

title: Coffee Cup Points Estimator
emoji: ☕️
colorFrom: gray
colorTo: green
sdk: gradio
sdk_version: 5.49.1
app_file: app.py
pinned: false

Module3Project

Overview

Predict coffee quality scores based on sensory attributes using a RandomForest model and an MLOps pipeline. This project demonstrates an end-to-end MLOps pipeline: data ingestion, preprocessing, model training, containerization, cloud deployment, and front-end integration.

Data

For this project, we are using data on coffee quality found here: https://www.kaggle.com/datasets/volpatto/coffee-quality-database-from-cqi

The cleaned coffee dataset is publicly hosted on Google Cloud Storage for reproducibility. The preprocessing pipeline automatically downloads it via the data.url field in config.yaml.

Cleaned data is hosted in Google Cloud Storage: https://storage.googleapis.com/coffee-quality-data/preprocessed_data.csv

Architecture

Data → Cloud (GCS) → Preprocess (ColumnTransformer) → Train (RandomForest) → FastAPI → Gradio frontend

Frontend Architecture

┌───────────────┐       ┌─────────────┐       ┌───────────────┐       ┌──────────────┐
│  Kaggle Data  │  →    │  GCS Bucket │  →    │  FastAPI (API)│  →    │ Gradio UI    │
└───────────────┘       └─────────────┘       └───────────────┘       └──────────────┘

Frontend

The Gradio-based frontend is deployed at: https://huggingface.co/spaces/averye-duke/Module3

Hugging face was used to deploy the app.

Cloud Deployment:

The FastAPI container is deployed on Google Cloud Run at: Base URL: https://coffee-api-354131048216.us-central1.run.app

Endpoints:

• /health – Health check
• /predict_named – POST endpoint for predictions
• /docs - API documentation (Swagger)

Example cURL:

curl -X POST "https://coffee-api-354131048216.us-central1.run.app/predict_named" \
  -H "Content-Type: application/json" \
  -d '{"rows":[{"Aroma":7.5,"Flavor":6.0,"Body":5.5,"Acidity":8.0,"Sweetness":9.0,"Balance":7.0,"Aftertaste":6.5,"Clean.Cup":9.0}]}'

Setup:

python -m venv venv
source venv/bin/activate        # Windows: venv\Scripts\activate
pip install --upgrade pip
pip install -r requirements.txt

Testing/running scripts

To test preprocess.py:

python scripts/preprocess.py

Confirm all output files exist by running:

ls -l data/cleaned/X_train.csv data/cleaned/X_test.csv data/cleaned/y_train.csv data/cleaned/y_test.csv artifacts/preprocessor.joblib

We wrote a unit test script tests/test_preprocessor.py, to run it:

pip install pytest
pytest -q

To run the server, do health check use sample predict payload:

uvicorn app.server:app --reload --port 8000 
curl http://127.0.0.1:8000/health
curl -X POST "http://127.0.0.1:8000/predict_named" \
  -H "Content-Type: application/json" \
  -d '{"rows":[ {"Aroma":7.5,"Flavor":6.0,"Number.of.Bags":1,"Category.One.Defects":0} ] }'

To train the model:

python scripts/train.py

Ensure artifacts/model.joblib was built

To run the UI app start the server and type in CLI:

python app/frontend.py
Enter 3 when prompted:
  wandb: (1) Create a W&B account
  wandb: (2) Use an existing W&B account
  wandb: (3) Don't visualize my results
  My personal login is needed to sign in here to update to wandb website

Open link in browser

Model

We used a RandomForestRegression for the model. Test size is 20% of dataset. Model has accuracy of 94.2% with 100 estimators.

W and B tracks model performance. Data can be found in wandb/run.../files/wandb-summary.json. Data is presented like this:

{
  "_timestamp":1.763876781125257e+09,
  "_wandb":{"runtime":2},
  "_runtime":2,
  "_step":0,
  "R2":0.9424069488737763,
  "RMSE":0.5528660703704987,
  "MAE":0.31615526315789416,
  "MAPE":0.39006294567905464
}

These perfomance metrics are also stored in artifacts.metrics.json like this:

{
    "R2": 0.9424069488737761,
    "RMSE": 0.5528660703704994,
    "MAE": 0.31615526315789455,
    "MAPE": 0.39006294567905514
}

The 94.2% R2 value shows very good fit and a cup score that correlates strongly with the other columns. The RMSE 0f 0.55 shows a small predicition error and therefore reinforces the model's high preformance. The MAE of 0.314 also shows a small error to the actual cup points. MAPE shows average percentage error of 39% which shows medium accuracy. This could be due to the small size dataset the model was trained on.

🐳 Docker and Testing

Build the image

# from the project root
docker build -t coffee-api:dev .
docker run --rm -e WANDB_MODE=offline -p 8000:8000 coffee-api:dev

Note: Use WANDB_MODE=offline (as shown above) when running inside Docker or CI to prevent login prompts from Weights & Biases. If you have a W&B API key, set it via WANDB_API_KEY=your_key to enable cloud logging.

Run the container

docker run --rm -p 8000:8000 \
  -v "$(pwd)/artifacts":/app/artifacts \
  -v "$(pwd)/config.yaml":/app/config.yaml \
  -v "$(pwd)/data":/app/data \
  coffee-api:dev

Then open: • Health check: http://127.0.0.1:8000/health • Interactive docs: http://127.0.0.1:8000/docs

If artifacts are missing, the container automatically runs scripts/preprocess.py to generate them.

Run tests inside the container

To verify reproducibility of preprocessing and data pipeline:

docker run --rm -v "$(pwd)":/app -w /app coffee-api:dev python -m pytest -q

Expect output:

...
3 passed in ~0.9s

Docker-related notes:

• Ports: container exposes 8000 (mapped to host port 8000)
• Artifacts (preprocessor.joblib, model.joblib) are mounted from the host for faster iteration

Limitations & Ethics

Predictions depend on sensory ratings, which are subjective. The model is not suitable for real-world evaluation of coffee quality without expert calibration. The dataset may contain sampling bias by country or producer, and model predictions should not be used for commercial grading without calibration against expert cuppers.

Notes / Gotchas

• config.yaml may include data.input_columns — if present the server will require/expect those columns and reindex incoming payloads automatically.
• The server will try to load artifacts/preprocessor.joblib and artifacts/model.joblib. If those are missing the server returns deterministic dummy predictions (development mode).

☁️ Cloud Services Used

• Google Cloud Storage (GCS): Stores the cleaned dataset (preprocessed_data.csv) publicly.
• Google Cloud Run: Hosts and serves the FastAPI model API container.
• Weights & Biases (W&B): Tracks model training metrics and performance.

🧠 Authors

• Eugenia Tate
• Avery Estopinal

References:

• OpenAI. (2025). ChatGPT (Version 5.1) [Large language model]. https://chat.openai.com We used ChatGPT (OpenAI GPT-5.1) to assist with code snippets. Portions of the preprocessing, frontend, train and most of server code were assisted by ChatGPT (OpenAI GPT-5.1). Authors verified and adapted the generated code. Authors fully understand what the code does and how to apply the knowledge in the future.
• Kaggle Coffee Quality Data (Volpatto, 2020) https://www.kaggle.com/datasets/volpatto/coffee-quality-database-from-cqi