yvnalvworks

Data Preprocessing

I clean, normalize, and transform raw data into analysis- and model-ready datasets, so your dashboards, metrics, and machine learning results are built on reliable foundations.

CleaningNormalizationFeature EngineeringData QualityPipelines

Outcomes

  • Higher data quality: fewer missing values, duplicates, and inconsistencies
  • More reliable KPIs and dashboards (less “garbage in, garbage out”)
  • Feature-ready datasets for modeling and forecasting
  • Reproducible transformations (not manual Excel steps)
  • Clear documentation of assumptions and preprocessing rules

Common use cases

Messy scraped or semi-structured data

Normalize inconsistent fields, fix parsing issues, and enforce schema consistency.

Machine learning dataset preparation

Handle missing values, encoding, scaling, and train/test splitting safely.

Time-series cleanup

Resample, handle gaps, align timestamps, and create reliable aggregates.

Feature engineering pipelines

Create meaningful features and ensure they’re reproducible across environments.

How I work

  1. Understand goals + downstream usage (analysis vs ML vs dashboard)
  2. Data audit (schema, missingness, duplicates, outliers, leakage)
  3. Define cleaning rules and transformations with clear assumptions
  4. Implement reproducible pipelines (scripts/notebooks/jobs)
  5. Validation checks (row counts, ranges, constraints, drift checks)
  6. Documentation + handover (so it’s maintainable)

What you get

  • Clean dataset in your desired format (CSV/Parquet/DB tables)
  • Reusable preprocessing pipeline (Python + config)
  • Data quality checks and validation rules
  • Documentation of transformations and assumptions
  • Optional: feature set ready for modeling

Ready to talk?

Email me your dataset context and what you’re trying to achieve. I’ll propose a cleaning and preprocessing plan that’s measurable and reproducible.

What to prepare

  • Data sample or schema
  • Known issues (missing values, duplicates, outliers)
  • Downstream usage (analysis, ML, dashboards)
  • Preferred output format
Email me