The comprehensive guide on Three Levels of Machine Learning Software: Data, Model, and Code Engineering 2024
Machine Learning (ML) is revolutionizing industries by enabling intelligent automation, predictive analytics, and decision-making. However, building an ML system is not just about training a model; it requires careful handling of data, models, and code to ensure efficiency, scalability, and robustness.
This blog explores: β
The three levels of ML software development
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Key methodologies for handling data, model, and code engineering
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Tools and technologies for each stage
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Challenges and best practices for deployment and monitoring
1. Understanding the Three Levels of ML Software

An ML-based application consists of three key components:
| Component | Purpose | Key Focus Areas |
|---|---|---|
| Data Engineering | Collects, processes, and prepares data for training | Ingestion, cleaning, transformation, labeling |
| Model Engineering | Develops, trains, and optimizes ML models | Feature engineering, training, tuning, evaluation |
| Code Engineering | Deploys ML models into software applications | API development, model serving, monitoring |
π Example:
A fraud detection system must collect customer transaction data (Data Engineering), train ML models to detect fraudulent behavior (Model Engineering), and integrate predictions into a banking application (Code Engineering).
2. Data Engineering: The Backbone of ML Systems

πΉ Why is Data Engineering Crucial?
Data Engineering accounts for 80% of the effort in ML projects. If data is unreliable, biased, or incomplete, ML models will fail in production.
Key Steps in Data Engineering
| Stage | Purpose | Common Tools |
|---|---|---|
| Data Ingestion | Collects raw data from multiple sources | Kafka, Flink, Airbyte |
| Data Exploration | Understands structure, distributions, and anomalies | Pandas, Dask, Great Expectations |
| Data Cleaning | Removes missing values, duplicates, and inconsistencies | Apache Spark, dbt |
| Data Transformation | Converts raw data into ML-ready features | Feature Store, Data Wrangling (Pandas, Scikit-learn) |
| Data Labeling | Annotates data for supervised learning | Labelbox, Amazon SageMaker Ground Truth |
| Data Splitting | Divides data into training, validation, and test sets | Scikit-learn, TensorFlow |
π Example:
A self-driving car collects real-time camera feeds and sensor data (ingestion), removes blurry images (cleaning), and labels road signs (labeling).
Best Practices for Data Engineering
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Use scalable data storage solutions (BigQuery, AWS S3, Delta Lake).
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Automate data validation to prevent bad data from entering pipelines.
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Ensure compliance with data privacy regulations (GDPR, HIPAA).
3. Model Engineering: Training and Optimizing ML Models

πΉ What is Model Engineering?
Model Engineering is the process of selecting, training, tuning, and evaluating ML models to make accurate predictions.
Key Steps in Model Engineering
| Stage | Purpose | Common Tools |
|---|---|---|
| Feature Engineering | Extracts meaningful features for ML models | Scikit-learn, Feature Stores (Feast) |
| Model Selection | Chooses the best algorithm for the problem | XGBoost, TensorFlow, PyTorch |
| Hyperparameter Tuning | Optimizes ML parameters for better accuracy | Optuna, Ray Tune |
| Model Evaluation | Tests model performance on unseen data | MLflow, Weights & Biases |
| Model Packaging | Converts the trained model into a deployable format | ONNX, TensorFlow SavedModel |
π Example:
A recommendation system trains a deep learning model on user purchase history, optimizes hyperparameters using Bayesian Optimization, and evaluates precision before deployment.
Best Practices for Model Engineering
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Use automated hyperparameter tuning to reduce manual experimentation.
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Track model versions using MLOps tools like MLflow.
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Ensure explainability and fairness to prevent biased predictions.
4. Code Engineering: Deploying and Scaling ML Models

πΉ Why is Code Engineering Critical?
A trained ML model is useless unless it is integrated into an application for real-time or batch inference.
Key Steps in Code Engineering
| Stage | Purpose | Common Tools |
|---|---|---|
| Model Deployment | Exposes trained models via REST APIs or microservices | TensorFlow Serving, FastAPI, Flask |
| Model Serving | Handles live inference requests | Kubernetes, TorchServe |
| Performance Monitoring | Tracks model drift and accuracy in production | Prometheus, EvidentlyAI |
| Model Retraining | Updates the model when performance drops | Airflow, Kubeflow |
π Example:
A chatbot uses NLP models deployed as a microservice with FastAPI and continuously monitors user feedback for retraining.
Best Practices for Code Engineering
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Use containerization (Docker, Kubernetes) to simplify deployment.
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Monitor models in production for accuracy decay.
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Implement rollback mechanisms in case a model update degrades performance.
5. Challenges in ML Software Development
| Challenge | Solution |
|---|---|
| Data Quality Issues | Use validation pipelines (Great Expectations) |
| Model Drift | Implement continuous monitoring & retraining |
| Scalability Issues | Use cloud-based model serving (AWS SageMaker, Vertex AI) |
| Security & Compliance | Apply role-based access and data encryption |
π Trend:
Companies are adopting MLOps (Machine Learning Operations) to automate and streamline data, model, and deployment workflows.
6. Emerging Trends in ML Software Engineering
π AutoML (Automated Machine Learning) β Reducing manual feature engineering and hyperparameter tuning.
π Federated Learning β Training models on decentralized data while preserving privacy.
π Explainable AI (XAI) β Enhancing model transparency for compliance and trust.
π Serverless ML β Deploying models without managing infrastructure (Google Cloud Functions, AWS Lambda).
π Edge AI β Running ML models on devices (IoT, mobile) instead of cloud servers.
7. Final Thoughts
Building ML-based applications requires expertise in data engineering, model development, and software deployment. By following best practices and leveraging modern MLOps tools, organizations can ensure reliability, scalability, and performance.
β Key Takeaways:
- Data Engineering ensures ML models are trained on clean, high-quality data.
- Model Engineering focuses on tuning, optimizing, and evaluating ML models.
- Code Engineering integrates ML models into production-ready applications.
- Automation and monitoring improve model reliability over time.
π‘ What challenges have you faced in ML software development? Letβs discuss in the comments! π