CF Bolz-Tereick
@cfbolz.bsky.social
PyPy/RPython contributor. Half time teaching at Uni Düsseldorf. Works on dynamic language implementations. Love street art and art in public spaces, hiking, reading.
they/them
they/them
Reposted by CF Bolz-Tereick
lol @hikikomorphism.bsky.social just described Ea-Nāṡir as "CMOT Dibbler (Assyrian Edition)"
November 6, 2025 at 2:31 AM
lol @hikikomorphism.bsky.social just described Ea-Nāṡir as "CMOT Dibbler (Assyrian Edition)"
Reposted by CF Bolz-Tereick
Tlingit artist Nicholas Galanin, “Architecture of return, escape (The British Museum)”, a deerskin map a floor plan of the British Museum and possible escape routes for various Indigenous cultural belongings held there.
September 6, 2025 at 5:46 PM
Tlingit artist Nicholas Galanin, “Architecture of return, escape (The British Museum)”, a deerskin map a floor plan of the British Museum and possible escape routes for various Indigenous cultural belongings held there.
Interpreter alignment chart
October 15, 2025 at 7:56 PM
Interpreter alignment chart
Reposted by CF Bolz-Tereick
it has been 0 days since I wrote a tiny interpreter to prototype some new database features. you will never regret writing a tiny interpreter
October 14, 2025 at 5:18 PM
it has been 0 days since I wrote a tiny interpreter to prototype some new database features. you will never regret writing a tiny interpreter
Reposted by CF Bolz-Tereick
It's spooky season! So I reviewed four great recent scary books:
Fiend by @almakatsu.bsky.social
Moonflow by @bitterkarella.bsky.social
Slashed Beauties by A Rushby
You Weren't Meant to be Human by @ajwhiteauthor.bsky.social
www.washingtonpost.com/books/2025/1...
Fiend by @almakatsu.bsky.social
Moonflow by @bitterkarella.bsky.social
Slashed Beauties by A Rushby
You Weren't Meant to be Human by @ajwhiteauthor.bsky.social
www.washingtonpost.com/books/2025/1...
4 terrifying new novels to get you through the scariest season
With an emphasis on body horror, these books by Alma Katsu, Bitter Karella, Andrew Joseph White and A. Rushby will leave you with a lingering sense of dread.
www.washingtonpost.com
October 14, 2025 at 5:18 PM
It's spooky season! So I reviewed four great recent scary books:
Fiend by @almakatsu.bsky.social
Moonflow by @bitterkarella.bsky.social
Slashed Beauties by A Rushby
You Weren't Meant to be Human by @ajwhiteauthor.bsky.social
www.washingtonpost.com/books/2025/1...
Fiend by @almakatsu.bsky.social
Moonflow by @bitterkarella.bsky.social
Slashed Beauties by A Rushby
You Weren't Meant to be Human by @ajwhiteauthor.bsky.social
www.washingtonpost.com/books/2025/1...
Reposted by CF Bolz-Tereick
📣 The “People from PSF” interview series continues! 🐍💬Meet the people behind the @python.org staff, directors & contributors making the magic happen.
💟 Meet Deb Nicholson
@eximious.bsky.social
🔗Read the full interview 👇
dennyperez.dev/projects/psf...
#Python #PyLadies #PSF #PeopleFromPSF
💟 Meet Deb Nicholson
@eximious.bsky.social
🔗Read the full interview 👇
dennyperez.dev/projects/psf...
#Python #PyLadies #PSF #PeopleFromPSF
October 9, 2025 at 4:32 PM
📣 The “People from PSF” interview series continues! 🐍💬Meet the people behind the @python.org staff, directors & contributors making the magic happen.
💟 Meet Deb Nicholson
@eximious.bsky.social
🔗Read the full interview 👇
dennyperez.dev/projects/psf...
#Python #PyLadies #PSF #PeopleFromPSF
💟 Meet Deb Nicholson
@eximious.bsky.social
🔗Read the full interview 👇
dennyperez.dev/projects/psf...
#Python #PyLadies #PSF #PeopleFromPSF
Reposted by CF Bolz-Tereick
The SPy project is kicking off community calls! 🎙️
Join us tomorrow (Oct 7th, 17:30 CEST) on Discord to chat, ask questions, and meet other SPy folks. Everyone’s welcome! 💚 🥸
Discord link: discord.gg/ZN4afjvq?eve...
Google calendar link: lnkd.in/d3U62QNn
Join us tomorrow (Oct 7th, 17:30 CEST) on Discord to chat, ask questions, and meet other SPy folks. Everyone’s welcome! 💚 🥸
Discord link: discord.gg/ZN4afjvq?eve...
Google calendar link: lnkd.in/d3U62QNn
Join the SPy lang Discord Server!
Check out the SPy lang community on Discord - hang out with 43 other members and enjoy free voice and text chat.
discord.gg
October 6, 2025 at 10:52 AM
The SPy project is kicking off community calls! 🎙️
Join us tomorrow (Oct 7th, 17:30 CEST) on Discord to chat, ask questions, and meet other SPy folks. Everyone’s welcome! 💚 🥸
Discord link: discord.gg/ZN4afjvq?eve...
Google calendar link: lnkd.in/d3U62QNn
Join us tomorrow (Oct 7th, 17:30 CEST) on Discord to chat, ask questions, and meet other SPy folks. Everyone’s welcome! 💚 🥸
Discord link: discord.gg/ZN4afjvq?eve...
Google calendar link: lnkd.in/d3U62QNn
Reposted by CF Bolz-Tereick
Last week I was lucky to take part in the CPython Core Dev Sprint.
This is a summary of what I did, including an annotated and extended version of my talk on tracing JITs in real-world Python scenarios, plus some comparisons between PyPy’s JIT and CPython’s new JIT.
👉 antocuni.eu/2025/09/24/t...
This is a summary of what I did, including an annotated and extended version of my talk on tracing JITs in real-world Python scenarios, plus some comparisons between PyPy’s JIT and CPython’s new JIT.
👉 antocuni.eu/2025/09/24/t...
Tracing JITs in the real world @ CPython Core Dev Sprint
My experience at the CPython Core Dev Sprint
antocuni.eu
September 24, 2025 at 2:55 PM
Last week I was lucky to take part in the CPython Core Dev Sprint.
This is a summary of what I did, including an annotated and extended version of my talk on tracing JITs in real-world Python scenarios, plus some comparisons between PyPy’s JIT and CPython’s new JIT.
👉 antocuni.eu/2025/09/24/t...
This is a summary of what I did, including an annotated and extended version of my talk on tracing JITs in real-world Python scenarios, plus some comparisons between PyPy’s JIT and CPython’s new JIT.
👉 antocuni.eu/2025/09/24/t...
Reposted by CF Bolz-Tereick
hey we have a lot of fun here, living in a fascist dystopia and goofing on the very real lives being ruined by the state, it's great, things are fine, we love it! Why not enjoy the end of civilization with a good book? why not do it with MY book?? www.hachettebookgroup.com/titles/bitte...
Moonflow
"A bizarre and fiercely original splatterpunk phantasmagoria of queerness. Deranged and gleefully weird as f*ck, this is an impressive debut from a singular...
www.hachettebookgroup.com
September 12, 2025 at 4:42 PM
hey we have a lot of fun here, living in a fascist dystopia and goofing on the very real lives being ruined by the state, it's great, things are fine, we love it! Why not enjoy the end of civilization with a good book? why not do it with MY book?? www.hachettebookgroup.com/titles/bitte...
Reposted by CF Bolz-Tereick
2008, I am driving back across the Canadian border from Montreal with @stillsostrange.bsky.social and @batwrangler.bsky.social in my tiny1998 Honda Civic sedan.
August 18, 2025 at 2:09 PM
2008, I am driving back across the Canadian border from Montreal with @stillsostrange.bsky.social and @batwrangler.bsky.social in my tiny1998 Honda Civic sedan.
Reposted by CF Bolz-Tereick
happy analog gender week nerds 💛🤍💜🖤
July 14, 2025 at 11:30 AM
happy analog gender week nerds 💛🤍💜🖤
Reposted by CF Bolz-Tereick
more specifically I'm looking for:
• summer jobs if it's in July or August
• part-time/contractual jobs if it's after September, with flexible hours so I can work alongside university
• summer jobs if it's in July or August
• part-time/contractual jobs if it's after September, with flexible hours so I can work alongside university
💼 Hello, I'm open for work!
I'm looking for my first professional experience as a junior programmer after an inconclusive college curriculum.
I'm currently based in the region of Normandy (France), but I can potentially move to another EU country provided that you help me with settling in. 🧵
I'm looking for my first professional experience as a junior programmer after an inconclusive college curriculum.
I'm currently based in the region of Normandy (France), but I can potentially move to another EU country provided that you help me with settling in. 🧵
June 25, 2025 at 8:07 PM
more specifically I'm looking for:
• summer jobs if it's in July or August
• part-time/contractual jobs if it's after September, with flexible hours so I can work alongside university
• summer jobs if it's in July or August
• part-time/contractual jobs if it's after September, with flexible hours so I can work alongside university
Reposted by CF Bolz-Tereick
OMG no!!! I still think Knuth's deep dive from "I want to write about algorithms" to "I need typesetting software" to "I need fonts" to "I need font software" to "I need software to write software" may be the most epic software exploration in human history, and kids these days have NO IDEA about it.
June 25, 2025 at 11:56 PM
OMG no!!! I still think Knuth's deep dive from "I want to write about algorithms" to "I need typesetting software" to "I need fonts" to "I need font software" to "I need software to write software" may be the most epic software exploration in human history, and kids these days have NO IDEA about it.
Reposted by CF Bolz-Tereick
New blog post by @cfbolz.bsky.social: "How fast can the RPython GC allocate?" pypy.org/posts/2025/0...
How fast can the RPython GC allocate?
While working on a paper about allocation profiling in
VMProf I got curious
about how quickly the RPython GC can allocate an object. I wrote a small
RPython benchmark program to get an idea of the ord
pypy.org
June 15, 2025 at 7:01 PM
New blog post by @cfbolz.bsky.social: "How fast can the RPython GC allocate?" pypy.org/posts/2025/0...
"How slow is the tracing interpreter of PyPy's meta-tracing JIT?" cfbolz.de/posts/speed-...
Spoiler: for the microbenchmark I tried, the slowdown of the meta-tracing interpreter is about 900x
Spoiler: for the microbenchmark I tried, the slowdown of the meta-tracing interpreter is about 900x
How slow is the tracing interpreter of PyPy's meta-tracing JIT?
I wanted to investigate the warmup behavior of the PyPy interpreter, so I wrote
a somewhat arbitrary microbenchmark:
all_results = set()
num = int(sys.argv[1])
class A(object):
pass
def main():
cfbolz.de
June 12, 2025 at 7:04 AM
"How slow is the tracing interpreter of PyPy's meta-tracing JIT?" cfbolz.de/posts/speed-...
Spoiler: for the microbenchmark I tried, the slowdown of the meta-tracing interpreter is about 900x
Spoiler: for the microbenchmark I tried, the slowdown of the meta-tracing interpreter is about 900x
@keleshev.com not sure whether you already saw, but Compiling to Assembly from Scratch got a review in c't 9/25 (the largest German IT magazine)
May 21, 2025 at 4:10 PM
@keleshev.com not sure whether you already saw, but Compiling to Assembly from Scratch got a review in c't 9/25 (the largest German IT magazine)
Reposted by CF Bolz-Tereick
We just merged an improvement to the PyPy JIT heap optimizations: type based alias analysis for Python instances. Work was done by @cfbolz.bsky.social and their student Nico Rittinghaus.
May 21, 2025 at 8:16 AM
We just merged an improvement to the PyPy JIT heap optimizations: type based alias analysis for Python instances. Work was done by @cfbolz.bsky.social and their student Nico Rittinghaus.
Reposted by CF Bolz-Tereick
Fast on the heels of the last release, I have published a PyPy v7.3.19 bug-fix release with PyPy2.7, PyPY3.10 and a beta-quality PyPy3.11. Please try it out! The complete release note is at doc.pypy.org/en/latest/re...
PyPy v7.3.19: release of python 2.7, 3.10 and 3.11 beta, released 2025-02-26 — PyPy documentation
doc.pypy.org
February 26, 2025 at 12:26 PM
Fast on the heels of the last release, I have published a PyPy v7.3.19 bug-fix release with PyPy2.7, PyPY3.10 and a beta-quality PyPy3.11. Please try it out! The complete release note is at doc.pypy.org/en/latest/re...
New blog post by my excellent master student Christoph Jung:
"Low Overhead Allocation Sampling with VMProf in PyPy's GC"
pypy.org/posts/2025/0...
Hopefully the first in a series about his work on a sampling allocation profiler for PyPy
"Low Overhead Allocation Sampling with VMProf in PyPy's GC"
pypy.org/posts/2025/0...
Hopefully the first in a series about his work on a sampling allocation profiler for PyPy
February 25, 2025 at 1:09 PM
New blog post by my excellent master student Christoph Jung:
"Low Overhead Allocation Sampling with VMProf in PyPy's GC"
pypy.org/posts/2025/0...
Hopefully the first in a series about his work on a sampling allocation profiler for PyPy
"Low Overhead Allocation Sampling with VMProf in PyPy's GC"
pypy.org/posts/2025/0...
Hopefully the first in a series about his work on a sampling allocation profiler for PyPy
I needed something quick and dirty to count the number of malloc calls in some C programs, and the total size of the allocated memory. @pablogsal.com very helpfully shared some LD_PRELOAD code with me, which solved the problem 🙏
gist.github.com/cfbolz/12ff1...
gist.github.com/cfbolz/12ff1...
LD_PRELOAD count mallocs
LD_PRELOAD count mallocs. GitHub Gist: instantly share code, notes, and snippets.
gist.github.com
February 15, 2025 at 6:42 PM
I needed something quick and dirty to count the number of malloc calls in some C programs, and the total size of the allocated memory. @pablogsal.com very helpfully shared some LD_PRELOAD code with me, which solved the problem 🙏
gist.github.com/cfbolz/12ff1...
gist.github.com/cfbolz/12ff1...
Since I was now wondering, here's PyPy VS CPython 3.x binary sizes
February 13, 2025 at 8:55 PM
Since I was now wondering, here's PyPy VS CPython 3.x binary sizes
Reposted by CF Bolz-Tereick
Interestingly enough PyPy 3.x is mostly smaller than 2.7. E.g. PyPy 3.11 is 58.8 MiB, despite having a bunch more features. I never quite figure out why. Just for comparison, CPython 3.11 is 25.2 MiB.
February 13, 2025 at 8:04 PM
Interestingly enough PyPy 3.x is mostly smaller than 2.7. E.g. PyPy 3.11 is 58.8 MiB, despite having a bunch more features. I never quite figure out why. Just for comparison, CPython 3.11 is 25.2 MiB.
Reposted by CF Bolz-Tereick
This is the size of PyPy 2.7, btw. It doesn't make sense to use the 3.x variant for this, because the size of that changes due to newer Python versions being implemented over time.
February 13, 2025 at 8:04 PM
This is the size of PyPy 2.7, btw. It doesn't make sense to use the 3.x variant for this, because the size of that changes due to newer Python versions being implemented over time.
Reposted by CF Bolz-Tereick
We don't do this regularly or anything, but every couple of years @cfbolz.bsky.social looks at how the PyPy binary sizes have developed. Looks like an ok balance between occasionally cleaning something up and thereby shrinking the binary; and then slow growth or explicit time/binary-size-tradeoffs.
February 13, 2025 at 8:04 PM
We don't do this regularly or anything, but every couple of years @cfbolz.bsky.social looks at how the PyPy binary sizes have developed. Looks like an ok balance between occasionally cleaning something up and thereby shrinking the binary; and then slow growth or explicit time/binary-size-tradeoffs.