The Test Set by Posit

dbt Labs CEO Tristan Handy drops into The Test Set to map the fault lines between the data science world and the enterprise data world — and explain why analytics engineers are basically pissed-off data analysts who decided to organize the bookshelf. We get into SQL's glow-up, the community magic of dbt Slack, what AI agents mean for data warehouses, and why everyone's building iOS apps with Claude now.
What's inside:
What analytics engineers *actually* do
SQL's journey from deeply unsexy to indispensable
How dbt turned source control into a source of truth
Building a tech community without the RTFM energy
AI agents on your data lake: permissions get personal
Will LLMs kill the open-source package ecosystem?
Edible gardening, welding dreams, and digital dysphoria

Nell Thomas has spent two decades in data — from equity research to the DNC to Facebook to leading a 400-person data org at Shopify. She walks Michael and Wes through the modern data stack role by role, gets honest about what AI is and isn't changing about data work, and admits the semantic layer has been her greatest leadership failure. Plus: Sneakers gets the respect it deserves.
Episode Notes
What does it actually look like to run data infrastructure for millions of merchants while the entire industry reinvents itself in real time? Nell Thomas (VP of Data, Shopify) talks vibe-coded dashboards, political campaign data scarcity, blameless postmortems, and why no one should be locking in on an AI strategy just yet. Recorded live in Times Square.
What’s Inside
Mapping the modern data stack, role by role
Why data quality is still the #1 problem
What "good scrutiny" looks like on a data team
Vibe coded dashboards and the trust problem
Shopify's MCP for their data warehouse
The throwaway tech problem in political campaigns
Why the semantic layer is so damn hard
Sneakers!

Phillip Cloud has been shaping the Python data ecosystem since the early pandas days — and he has *opinions*. Now a principal engineer at NVIDIA leading the Ibis project, Phillip talks about how he stumbled into open source via an eye movement lab, why he prefers his coding agents cold and emotionless, and what happens when you ask an LLM for woodworking trig. Plus: terminal user interfaces, the file hierarchy standard hot take nobody asked for, and the pineapple-on-pizza hill he's willing to die on.
Episode Notes
Phillip Cloud (NVIDIA, Ibis project) joins Michael Chow, Wes McKinney, and Hadley Wickham to talk about his path from eye movement labs to pandas core team, why developer productivity tools have quietly gotten amazing, his brutally honest take on coding agents, and what it would actually take to impress him. Also: VisiData love, NixOS evangelism, and yard work as therapy.
What’s Inside
From eye movement labs and MATLAB to pandas core team
Column multi-indexes: the feature nobody likes but Phillip needed
Why your command line tool better have a sweet TUI
VisiData: the terminal data tool you're sleeping on
Are we writing code for humans or for agents now?
Phillip's AI skepticism journey: Cursor, Claude Code, and frustration
The Numba CUDA test suite port that would finally impress him

Charlie Marsh built Ruff, uv, and Ty — the tools that mass-fixed Python's worst pain points. Now he's grappling with what happens when agents start writing most of the code. In this episode, Charlie gets real about his team trusting his PRs less, the gnarly middle of coding with agents, and whether Python is even the right language for an agentic future. It's honest, a wee existential, and deeply relatable if you ship code for a living.
Episode Notes
Charlie Marsh is the founder and CEO of Astral — the company behind Ruff, uv, and Ty. He sits down with Michael and Wes to talk about what it's actually like building with coding agents every day, why his team's code review dynamics completely changed, and big open questions about code quality, open source community, and Python's future nobody has answers to yet.
What’s Inside
How Ruff convinced mass adoption when switching tools is painful
Why "just uv run it" became the killer feature
Hiring outside Python's ecosystem to build tools for it
His team said "we trust your PRs less now"
Engineers screen-sharing their actual agent workflows at Astral
The "Lisp Curse" reborn: cheap code breaking open sourceIs 
Python the wrong language for an agentic world?

Alenka Frim went from teaching yoga full-time to becoming a committer and PMC Member on Apache Arrow. In this episode, Alenka joins The Test Set hosts to talk about how Arrow grew from spec to critical infrastructure, and why she started contributing to a project she had never even used. She reflects on imposter syndrome, the discipline of showing up (on the mat and in GitHub), and how agents are changing what it means to write code. Plus: managing 4,000 open issues without losing your mind.

Episode Notes
Alenka's path into Arrow is unconventional: Sshe wasn't looking for a job, she wasn't using the tool, and she'd spent the previous five years focusing on mind-body fitness. But open source felt like the right place to learn, have fun, and figure things out, so she jumped in. What followed was a journey from her first R bindings to becoming a PMC member on one of the most critical pieces of data infrastructure in the world.

What’s Inside
Alenka's journey, from yogi to Arrow committer
Signs of a healthy open source community: people, dialogue, and turnover
Arrow as critical infrastructure: DuckDB, Polars, Pandas, and the spec that unifies them
Managing 4,000 open issues without losing your mindImposter syndrome in open source
What the yoga mat teaches you about discipline and collaborationAI and the future of programming: 100x more software or 10x better software?