Behind the Commit

The Best of Two Languages: Connecting C++ & Python with Cristián Maureira-Fredes

Thu, 09 Jul 2026 18:05:33 GMT

What does a PhD in Astrophysics have in common with the software running in your car, your coffee machine, and NASA’s internal tools? In this episode I sit down with Cristian Maureira-Fredes, a Research and Development Principal Manager at The Qt Company. Cristian leads the team behind Qt for Python (PySide6) and the Qt Core team.

Inside PyPI: Maria Ashna on Supporting Python's Package Index

Fri, 05 Jun 2026 14:12:24 GMT

In this episode, I'm chatting with Maria Ashna — PyPI support specialist at the Python Software Foundation and founder of Magic Lightbulb, a tech and product consulting firm. PyPI serves nearly a million developers and is the backbone of Python's entire package ecosystem — maintained by a team of just four people. Maria shares what her role actually looks like day to day, how she cleared a backlog that was delayed by over a year, what happens when a package maintainer passes away, and what's coming next for PyPI organizations.

Outline

0:00 Episode highlights

0:45 Introduction to Maria Ashna

1:11 What does a PyPI support specialist actually do?

2:07 The history of PyPI — born in 2003, formerly "the cheese shop"

2:47 How many people work on PyPI?

3:27 Most common support issues: account recovery and 2FA

3:48 2FA is now 100% mandatory on PyPI

4:10 Clearing a 500+ ticket backlog delayed by over a year

6:14 What is PEP 541?

7:01 What happens when users don't respond?

8:07 The edge case nobody thinks about: users who have passed away

8:30 How to open a ticket with the PyPI team

10:43 PyPI Organizations: what are they and who are they for?

13:17 Is PyPI going commercial? (No)

15:01 Nearly 1 million users, team of 4

15:38 How do you actually pronounce PyPI?

16:13 Where to find Maria online

Episode links

– PyPI: https://pypi.org

– PEP 541: https://peps.python.org/pep-0541/

– Maria on GitHub: https://github.com/despy-brain

– Contact Maria: maria@python.org

Trailer – Inside PyPI: Maria Ashna on Supporting Python's Package Index

Fri, 05 Jun 2026 14:10:31 GMT

In this upcoming episode, I chat with Maria Ashna, PyPI support specialist at the Python Software Foundation. We discuss what it's actually like to support nearly a million Python developers with a team of four, the edge cases nobody thinks about, and what PyPI was called before it was PyPI.

Full episode coming out soon!

Why Python is Slow: Antonio Cuni on SPy and Statically Compiled Python

Thu, 30 Apr 2026 12:02:08 GMT

Antonio Cuni (principal engineer at Anaconda, author of SPy, developer of PyScript and PyPy, co-founder of the HPy project, and creator of PDB++, Fancy Completer, and VMProf) shares why Python is slow and how SPy, a new statically compiled variant of Python, aims to be as fast as C while staying as Pythonic as Python. We discuss the trade-off between dynamic features and performance, how SPy's "red and blue" code model replaces best-effort JIT with predictable errors, why PyPy struggles with C extensions, and what "Pythonic" really means.

Outline

00:00 - Episode highlights and introduction

00:40 - Why is Python so slow?

01:31 - Would a static Python be fast?

02:13 - What is SPy?

02:28 - What motivated you to create SPy? (Spoiler: frustration)

03:52 - Which ideas from PyPy and HPy went into SPy?

06:36 - Biggest challenges of building SPy

07:49 - What does "Pythonic" actually mean?

10:39 - Current roadmap and the two-level language idea

12:24 - Walking through the SPy compilation pipeline

13:57 - Red-shifting and the blue/red AST nodes

14:40 - Why blue and red? (No, it's not from The Matrix)

15:52 - PyPy vs SPy: when to use which

19:34 - C extensions and the C API problem

20:04 - How to actually make your Python code faster

23:34 - Memory management and garbage collection in SPy

24:44 - When will SPy be production-ready?

25:44 - How to contribute to SPy

26:26 - Where does the name "SPy" come from?

Note: the episode was recorded in July 2025 and some features, such as list type, garbage collector, and documentation, have been implemented in the meantime. In the section below you can find the links to those features.

Episode links

– SPy on GitHub: https://github.com/spylang/spy

– PyPy: https://pypy.org/

– HPy project: https://hpyproject.org/

– PyScript: https://pyscript.net/

– Anaconda: https://www.anaconda.com/

– decorators in SPy: https://github.com/spylang/spy/pull/225

– SPy roadmap: https://github.com/spylang/spy/blob/main/ROADMAP.md

– list type in SPy: https://github.com/spylang/spy/blob/main/stdlib/_list.spy

– garbage collector in SPy: https://github.com/spylang/spy/pull/390

– SPy documentation: https://spylang.github.io/docs/dev/

– series of blog posts on SPy: https://antocuni.eu/2025/10/29/inside-spy-part-1-motivations-and-goals/

Trailer – Why Python is Slow: Antonio Cuni on SPy and Statically Compiled Python

Thu, 30 Apr 2026 10:40:12 GMT

In this upcoming episode, I chat with Antonio Cuni, the creator of SPy and long-time PyPy developer. We discuss why Python is slow, how a statically compiled Python variant can be as fast as C while still feeling Pythonic, and the "red and blue" model behind SPy's compilation pipeline.

Full episode coming out soon!

Maintaining 80 OSS Projects: Anthony Sottile on pre-commit and Developer Tooling

Mon, 30 Mar 2026 13:56:00 GMT

In this episode, I'm chatting with Anthony Sottile — creator of pre-commit, primary maintainer of flake8, core contributor to pytest, and maintainer of around 80 open source projects across the Python ecosystem. He's also a GitHub Star and a popular live coding streamer on Twitch under the name "anthonywritescode". We dig into how he actually manages all of it, the origin story of pre-commit, the psychological side of open source maintenance, and how to get started contributing.

Outline

00:00 Episode highlights & Intro

0:59 The all-repos tool — distributed refactoring across repos

2:04 Where the idea came from (Yelp's microservices explosion)

2:42 Tools for managing multiple repositories

3:34 How pre-commit got started (a college group project)

4:15 Rewriting pre-commit for Yelp in 2018

4:46 Hardest technical challenge: supporting 13 programming languages

6:07 Surprising bugs found in NPM and Git

7:05 GitHub Stars and open source funding

8:10 How Sentry approaches funding open source

8:43 The psychological challenges of open source maintenance

10:06 What would you tell your past self?

11:32 How to start contributing to open source

13:05 Why Anthony started streaming on Twitch

13:52 What motivates him to keep streaming

14:58 Has community interaction changed how you design code?

15:48 Where to find Anthony online

Episode links

– pre-commit: https://pre-commit.com

– all-repos: https://github.com/asottile/all-repos

– Anthony's YouTube: https://www.youtube.com/@anthonywritescode

– Anthony's Twitch: https://www.twitch.tv/anthonywritescode

Trailer – Maintaining 80 OSS Projects: Anthony Sottile on pre-commit and Developer Tooling

Wed, 25 Mar 2026 09:25:22 GMT

In this upcoming episode, I chat with Anthony Sottile — creator of pre-commit and maintainer of around 80 open source projects. We talk about how he actually manages it all, the surprising bugs he's found in NPM and Git along the way, and the psychological side of open source that nobody talks about.

AI-Written Code: Armin Ronacher on AI Agents and the Future of Programming

Fri, 13 Feb 2026 08:15:00 GMT

Armin Ronacher (creator of Flask, previously Sentry’s VP of Platform, and currently founder of a startup Earendil) shares his experience building a startup where 90% of the code is AI-generated. We discuss which programming languages work best with AI agents, why Python's ecosystem makes life harder for AI, and what skills programmers need to stay relevant in the age of AI.

Outline

00:00 Episode highlights and introduction

0:43 - How much code do you write yourself vs AI agents?

2:03 - What kind of problems are suitable for AI and what do you solve yourself?

4:02 - Why do AI agents work better with certain languages like Go vs Python?

7:15 - How to steer AI agents in certain directions?

12:01 - What patterns can AI agents handle well?

15:28 - When starting a new project, what language do you use now?

16:27 - Do you monitor agents and what safeguards do you have?

18:48 - How do you handle parallelization with multiple agents?

19:34 - How should we handle licenses for AI-generated open source libraries?

24:07 - What is the future of programming jobs?

26:31 - What skills should programmers learn to stay competitive?

31:05 - Tips on how to get started with AI agents?

33:44 - How to stay up to date with all the recent changes?

36:16 - Where can people find you online?

Episode links

– Claude Code: https://claude.ai/

– UV (Python package manager): https://github.com/astral-sh/uv

– Simon Willison's blog: https://simonwillison.net/

– Armin's blog: https://lucumr.pocoo.org/

Trailer – AI-Written Code: Armin Ronacher on AI Agents and the Future of Programming

Thu, 12 Feb 2026 23:48:33 GMT

In this upcoming episode, I chat with Armin Ronacher, the creator of Flask. We discuss which programming languages work best with AI agents, why Python's ecosystem makes life harder for both humans and AI, and what skills programmers need to stay relevant in the age of AI.

AI-Generated Music: Tech, Copyright & Real-World Applications with Mateusz Modrzejewski

Wed, 03 Dec 2025 16:29:16 GMT

In this episode, I talk with Mateusz Modrzejewski, a professional musician and AI researcher and assistant professor at the Warsaw University of Technology, about AI-generated music: how it works, what artists think about it, the big copyright questions, and where AI tools can genuinely support the creative process instead of replacing it.

Outline

00:00 Episode highlights and introduction

00:49 Thoughts on AI-generated music

02:09 The good sides of AI

03:40 The bad sides of AI

04:43 How do professional musicians feel?

08:03 The data scraping problem and data poisoning research

11:33 How AI music generation actually works

15:04 How to start experimenting with AI music

18:26 Future of the music industry

25:22 The AI song contest

29:15 Resources to learn more

🎙️ This episode was recorded live at the Venture café at PyWaw in Warsaw.

Episode links

AI song contest: https://www.aisongcontest.com/
Librosa library: https://github.com/librosa/librosa
Pedalboard library: https://github.com/spotify/pedalboard
Intelligent Instruments Lab: https://iil.is/
PanGenerator: https://pangenerator.com/
Pyo library: https://github.com/belangeo/pyo
ISMIR tutorials: https://ismir.net/resources/tutorials/
Beyond supervised learning book: https://music-classification.github.io/tutorial/landing-page.html
Fundamentals of Music Processing book: https://www.researchgate.net/publication/288774112_Fundamentals_of_Music_Processing
NIME conference: https://www.nime.org/
ZAiKS Lab https://www.zaikslab.tech
⁠Warsaw University of Technology https://www.pw.edu.pl

Trailer – AI-Generated Music: Tech, Copyright & Real-World Applications with Mateusz Modrzejewski

Tue, 02 Dec 2025 21:29:07 GMT

AI-generated music is on the rise, but what does that mean from a technical and creative perspective? In this upcoming episode, I talk with Mateusz Modrzejewski, a professional musician and AI researcher, about AI-generated music: how it works, what artists think about it, the big copyright questions, and where AI tools can genuinely support the creative process instead of replacing it.

How To Make Web More Sustainable? – Chat with Thibaud Colas

Fri, 14 Nov 2025 11:59:59 GMT

In this episode, I’m chatting with Thibaud Colas — Product Lead & Engineering Manager at Torchbox, Wagtail product lead, and current President of the Django Software Foundation. We talk about digital sustainability: why the internet’s energy use matters, how to measure it, why performance is important for emissions, whether rewriting everything in Rust is the only solution, and why we should keep AI businesses more accountable.

Outline

0:00 — Episode highlights

0:58 — Guest intro

1:21 — Is carbon footprint a popular topic among developers?

3:44 — What’s the carbon impact of the web and software in general?

5:35 — How can we measure a website’s carbon footprint?

8:26 — What are Django’s and Wagtail’s plans to reduce their footprint?

9:35 — Does the programming language we use (e.g., Python or Rust) make a difference?

11:42 — What practical steps can developers take to lower their software’s impact?

12:25 — How do we raise awareness and make sustainability a mainstream topic in tech?

15:34 — Should businesses be accountable for their software’s footprint?

16:59 — What should AI companies and cloud providers be more transparent about?

Episode links

– Sustainable Web Design (methodology): https://sustainablewebdesign.org/

– Wagtail CMS (Torchbox): https://wagtail.org/

– Django Software Foundation: https://www.djangoproject.com/foundation/

– Climate Action Tech community: https://climateaction.tech/

– W3C work on web sustainability: https://w3c.github.io/sustainableweb-wsg/

Trailer – How To Make Web More Sustainable? – Chat with Thibaud Colas

Fri, 14 Nov 2025 11:41:03 GMT

What is digital sustainability and why does it matter?

In this upcoming episode, I chat with Thibaud Colas, Product Lead & Engineering Manager at Torchbox, Wagtail product lead, and current President of the Django Software Foundation. We talk about digital sustainability: why the internet’s energy use matters, how to measure it, why performance is important for emissions, whether rewriting everything in Rust is the only solution, and why we should keep AI businesses more accountable.

Why FastAPI Became Python’s Fastest‑Growing Framework – Chat with Sebastián Ramírez

Thu, 30 Oct 2025 17:13:28 GMT

In this episode, I’m chatting with Sebastián Ramírez — the creator of FastAPI, Typer, and SQLModel, and founder of FastAPI Labs. FastAPI has become one of Python’s fastest-growing web frameworks (adoption jumped from 14% to 25% among developers between 2021 and 2023!), and we dig into how it got here and what’s next on the roadmap. Sebastián shares behind-the-scenes insights into its success, his take on developer experience, the story behind FastAPI Labs and FastAPI Cloud, and how he handles life in open source.

Outline

0:00 Why FastAPI Became So Popular

1:43 The Philosophy Behind FastAPI Development

3:18 Challenges of Maintaining a Popular Open Source Project

5:50 Community Contributions & Recognition System

8:42 FastAPI Roadmap

11:13 Amazing Use Cases - From Particle Accelerators to Space Research

12:29 FastAPI's Performance Architecture & Python Core Team

15:19 Meeting Your Heroes & Being Popular in the Community

16:30 Dealing with Negative Comments & Online Criticism

23:25 FastAPI Cloud & FastAPI Labs Announcement

28:08 Deployment Challenges & Platform as a Service Solution

31:17 The SQLModel Challenge - Combining Old and New Magic

34:29 Thoughts on Education & Self-Taught Development

40:22 How to Contribute to FastAPI

42:33 Closing Thoughts

Episode links

– JetBrains Developers Survey 2023: https://www.jetbrains.com/lp/devecosystem-2023/python/#python_web_libs_two_years

– FastAPI documentation: https://fastapi.tiangolo.com

– Sebastián Ramírez’s website: https://tiangolo.com

– FastAPI Labs (FastAPI Cloud): https://fastapilabs.com/

Trailer - Why FastAPI Became Python’s Fastest‑Growing Framework – Chat with Its Creator

Thu, 23 Oct 2025 13:17:16 GMT

FastAPI has become one of Python’s fastest-growing web frameworks!

In this upcoming episode, I chat with Sebastián Ramírez, the creator of FastAPI, Typer, and SQLModel, and founder of FastAPI Labs. We talk about why FastAPI became so popular, the challenges of maintaining a fast-growing open source project, and what’s next for FastAPI and FastAPI Cloud.

Full episode coming out next week!

Behind the Python Release: Motivation, Fails & Rituals with Łukasz, Pablo & Hugo

Tue, 14 Oct 2025 16:06:16 GMT

Have you ever wondered how a CPython release works? In this episode, I talk with Hugo van Kemenade, Pablo Galindo Salgado, and Łukasz Langa about CPython release management.

About the guests

Hugo van Kemenade – Release Manager for Python 3.14 & 3.15, currently employed at the Sovereign Tech Agency as a fellow. Maintainer of open-source projects such as Pillow. Co-organizer of local Python events in Helsinki.
Pablo Galindo Salgado – Core Python developer, currently employed in the Software Infrastructure department at Bloomberg. Release Manager for Python 3.10 & 3.11, and a member of the Steering Council. Co-host of the core.py podcast.
Łukasz Langa – Python’s Developer in Residence at the PSF and Release Manager for Python 3.8 & 3.9. Creator of Black, the opinionated Python code formatter, and co-host of the core.py podcast.

Outline

01:34 Most & Least Successful Releases

05:34 Evolution of Release Process

11:37 Release Schedule and Annual Releases

15:05 Handling PRs and Reverts

18:07 Becoming a Python Release Manager

25:24 Motivation and Time Zone Challenges

29:36 Release Rituals and YouTube Party

35:11 Sustainable Open Source Funding Models

42:10 Getting Involved & Further Listening

🎙️ This episode was recorded live at EuroPython in July 2025 in Prague.

Episode links

- core.py podcast https://open.spotify.com/show/1PGRfdrLEwgXjQbPBNk1pW

- Python’s Developer Guide https://devguide.python.org/

- PEP 101 https://peps.python.org/pep-0101/

Trailer – Behind the Python Release: Motivation, Fails & Rituals with Łukasz, Pablo & Hugo

Sat, 11 Oct 2025 21:14:52 GMT

Sneak peak of the episode about CPython release. Have you ever wondered how a CPython release works? In this episode, we talk with Hugo van Kemenade, Łukasz Langa, and Pablo Galindo Salgado about Python release management.

About the guests

Hugo van Kemenade – Release Manager for Python 3.14 & 3.15, currently employed at the Sovereign Tech Agency as a fellow. Maintainer of open-source projects such as Pillow. Co-organizer of local Python events in Helsinki.
Pablo Galindo Salgado – Core Python developer, currently employed in the Software Infrastructure department at Bloomberg. Release Manager for Python 3.10 & 3.11, and a member of the Steering Council. Co-host of the core.py podcast.
Łukasz Langa – Python’s Developer in Residence at the PSF and Release Manager for Python 3.8 & 3.9. Creator of Black, the opinionated Python code formatter, and co-host of the core.py podcast.