Demand Forecasting PoC
Benchmarked an early vendor demand-forecasting model against ARIMA on ~600 GB of retail sales history.
- role
- Python Developer
- period
- 2020 – 2021
Problem
A large US retailer weighing an alpha-stage automl-based demand-forecasting model before committing to it.
What was built
- Analysis of ~600 GB of sales history (BigQuery, three years, apparel).
- Feature engineering plus training and validation code around the vendor AutoML model.
- A benchmark against ARMA / ARIMA / ARIMAX and a summary report for the client.
Outcome
The simple ARMA baseline outperformed the alpha-stage vendor model — a data-backed technology assessment delivered before any rollout decision.
Challenges and Lessons
- Communication is key to project success — even small message counts.
- Each query against a large dataset has a real cost — a FinOps lesson; use BigQuery’s row-preview instead of a full query when it’s sufficient.
- Feature engineering often matters more than model choice.
- Simpler solutions (ARIMAX-class models) can be more accurate and cheaper than very complex ones (AutoML).
- Before constructing models, one should deeply understand the data and its characteristics.