Before vs After FinFeedAPI
| Feature engineering | Before | After (with Flat Files S3) |
| Pulling historical data | Slow, paginated API calls or manual exports. | Bulk downloads of complete daily OHLCV datasets. |
| Dataset consistency | Data differs between runs, breaking reproducibility. | Stable, date-based files reused across experiments. |
| Preprocessing effort | Significant time spent cleaning and aligning data. | Clean CSV structure reduces preparation work. |
| Scaling experiments | Pipelines slow down as symbols or time ranges grow. | Parallel-friendly access supports large feature pipelines. |
| Debugging features | Hidden data issues surface late in modeling. | Clear raw inputs make edge cases visible early. |
| Tool integration | Custom ingestion logic for each environment. | Works with standard S3 tools and data science stacks. |
| Experiment repeatability | Hard to reproduce exact feature inputs. | Exact datasets can be reused and referenced. |
| Time to iteration | Long feedback loops slow feature discovery. | discovery. Faster iteration from data to features to models. |







