The Modern Python Data Stack: Polars, DuckDB and Marimo
Pandas is no longer the default. Here is the lean Python data stack I reach for in 2026 — and why it is 10x faster on most workloads.

If you are still reaching for pandas + Jupyter by reflex, your stack is a generation behind.
Polars
A DataFrame library written in Rust with a query optimizer. The API is similar to pandas but eager and lazy execution are first-class. On 10M-row joins it is routinely 5-20x faster.
DuckDB
An in-process analytical SQL engine. Read Parquet, CSV, JSON or Arrow directly with zero ETL. Pair it with Polars and you have a local data warehouse on your laptop.
Marimo
A reactive notebook that stores files as plain .py. No hidden state, real git diffs, deployable as an app. Jupyter still has the mindshare, but Marimo wins on every objective axis.
A typical pipeline
import polars as pl
import duckdb
df = pl.scan_parquet("events/*.parquet")
agg = duckdb.sql("SELECT country, count(*) FROM df GROUP BY 1").pl()
Three tools, no Spark cluster, no Airflow, and it scales further than most people need.