Streamlit

I ship Python data apps quickly with Streamlit: clean UI, Altair charts, CSV/Parquet export, and robust back-end patterns (secrets via env / st.secrets, pagination & retries, SQLite caching, and small feature flags through query params).

• pandas transforms, input validation, and data quality checks.
• Altair v5 interactive charts; responsive layouts.
• Export buttons & friendly error handling.
• Lightweight deploys with clear configuration.