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← The steady stream of "we had to rewrite the whole thing because it was…
17 connected korrents · 14 moments from 22 Mar 2025 to 31 Aug 2026.
Everything filed under software performance
software performance
Everything filed under compilers
compilers
Everything filed under Python
Python
Everything filed under software quality
software quality
Everything filed under developer tools
developer tools
Everything filed under data centers
data centers
Everything filed under LLMs
LLMs
Everything filed under coding agents
coding agents Same subject Same subject Same subject Same subject Same subject Same subject Same subject Same subject Same subject Same subject Same subject Same subject Same subject Same subject Same subject Same subject Same subject Read this korrent: The steady stream of "we had to rewrite the whole thing because it was too slow" engineering blog posts is the proof that deferring performance to hotspot optimization does not work. The steady stream of "we had to rewrite the whole thing because it was too slow" engineering blog posts is the proof that deferring performance to hotspot optimization does not work. Last stated 2 months ago
26 Aug 2026
CM
Casey Muratori — holds since 2026-08-26 — tap for who they are
Same subject: Hand-optimizing hot spots barely matters any more, because the libraries are already fast and CPUs are extremely good at running bad code quickly; what is left is architecture. — tap to centre the map on it Hand-optimizing hot spots barely matters any more, because the libraries are already fast and CPUs are extremely good at running bad code quickly; what is left is architecture. Last stated 2 months ago
26 Aug 2026
CM
Casey Muratori — holds since 2026-08-26 — tap for who they are
Same subject: "Optimize it later" would be safe advice only if every engineer already knew how to avoid the architectural mistakes that no later optimization can remove. — tap to centre the map on it "Optimize it later" would be safe advice only if every engineer already knew how to avoid the architectural mistakes that no later optimization can remove. Last stated 2 months ago
26 Aug 2026
CM
Casey Muratori — holds since 2026-08-26 — tap for who they are
Same subject: Traditional performance engineering methods are insufficient for the scale of modern AI datacenters and need new approaches. — tap to centre the map on it Traditional performance engineering methods are insufficient for the scale of modern AI datacenters and need new approaches. Last stated 8 months ago
6 Feb 2026
BG
Brendan Gregg — holds since 2026-02-06 — tap for who they are
Same subject: Performance work used to mean half a day reading traces before writing a single fix, and language models have collapsed that step to minutes. — tap to centre the map on it Performance work used to mean half a day reading traces before writing a single fix, and language models have collapsed that step to minutes. Last stated 2 months ago
19 Aug 2026
AO
Addy Osmani — holds since 2026-08-19 — tap for who they are
Same subject: The code today’s models and agents write is very hard to follow: you get better performance without knowing why, and no way to fix it when it breaks. — tap to centre the map on it The code today’s models and agents write is very hard to follow: you get better performance without knowing why, and no way to fix it when it breaks. Last stated 3 months ago
19 Jul 2026
ES
Elizabeth Stone — holds since 2026-07-19 — tap for who they are
Same subject: Repeated rewrites are the correct answer under fast growth, because a system specified to scale forever would take so long to build that the company would die before it shipped. — tap to centre the map on it Repeated rewrites are the correct answer under fast growth, because a system specified to scale forever would take so long to build that the company would die before it shipped. Last stated 7 months ago
1 Apr 2026
TP
Thuan Pham — holds since 2026-04-01 — tap for who they are
Same subject: AI did not create the bottlenecks in software delivery; it threw gas on processes everybody already knew were weak. — tap to centre the map on it AI did not create the bottlenecks in software delivery; it threw gas on processes everybody already knew were weak. Last stated 7 months ago
22 Mar 2026
NF
Nicole Forsgren — holds since 2026-03-22 — tap for who they are
Same subject: Most software rewrites fail and take longer than people expect them to. — tap to centre the map on it Most software rewrites fail and take longer than people expect them to. Last stated 2 years ago
19 Apr 2025
BK
Ben Kuhn — holds since 2025-04-19 — tap for who they are
Same subject: A compiler that also serves an IDE has to be lazy and deferred throughout — a different way of building compilers from the one the textbooks teach. — tap to centre the map on it A compiler that also serves an IDE has to be lazy and deferred throughout — a different way of building compilers from the one the textbooks teach. Last stated 5 months ago
13 May 2026
AH
Anders Hejlsberg — holds since 2026-05-13 — tap for who they are
Same subject: A good tool raises the floor of what people can build without lowering the ceiling, and almost every tool quietly lowers the ceiling. — tap to centre the map on it A good tool raises the floor of what people can build without lowering the ceiling, and almost every tool quietly lowers the ceiling. Last stated a year ago
18 Sept 2025
TL
Tobias Lütke — holds since 2025-09-18 — tap for who they are
Same subject: A new API framework that ignores how existing apps were historically built undermines its own introduction — tap to centre the map on it A new API framework that ignores how existing apps were historically built undermines its own introduction Last stated 2 months ago
31 Aug 2026
CH
Craig Hockenberry — holds since 2026-08-31 — tap for who they are
Same subject: A compiler that names every place a change breaks turns refactoring into fixing errors until the compiler stops shouting. — tap to centre the map on it A compiler that names every place a change breaks turns refactoring into fixing errors until the compiler stops shouting. Last stated 5 months ago
20 May 2026
AR
Alice Ryhl — holds since 2026-05-20 — tap for who they are
Same subject: A programming language is not a compiler but an experience: editing, running, debugging and the runtime library all have to fit together as one cycle. — tap to centre the map on it A programming language is not a compiler but an experience: editing, running, debugging and the runtime library all have to fit together as one cycle. Last stated 5 months ago
13 May 2026
AH
Anders Hejlsberg — holds since 2026-05-13 — tap for who they are
Same subject: A speed difference between languages that share the LLVM backend measures the benchmark author, not the languages. — tap to centre the map on it A speed difference between languages that share the LLVM backend measures the benchmark author, not the languages. Last stated 2 years ago
22 Mar 2025
TH
ThePrimeagen — holds since 2025-03-22 — tap for who they are
Same subject: A language can keep changing without a Python-2-to-3 break, as long as code written under the old and the new rules can be mixed freely in one program. — tap to centre the map on it A language can keep changing without a Python-2-to-3 break, as long as code written under the old and the new rules can be mixed freely in one program. Last stated 5 months ago
20 May 2026
AR
Alice Ryhl — holds since 2026-05-20 — tap for who they are
Same subject: Python is ugly: full of superfluous instructions kept since 1987 for legacy reasons, and its __init__ offends the sensibilities to the core. — tap to centre the map on it Python is ugly: full of superfluous instructions kept since 1987 for legacy reasons, and its __init__ offends the sensibilities to the core. Last stated a year ago
12 Jul 2025
DH
David Heinemeier Hansson — holds since 2025-07-12 — tap for who they are
Same subject: Sharing code between classes via inheritance in Python tends to produce a bad experience. — tap to centre the map on it Sharing code between classes via inheritance in Python tends to produce a bad experience. Last stated 3 months ago
21 Jul 2026
JE
Julia Evans — holds since 2026-07-21 — tap for who they are
At the centre
The steady stream of "we had to rewrite the whole thing because it was too slow" engineering blog posts is the proof that deferring performance to hotspot optimization does not work.
Holds Read this korrent →
Hand-optimizing hot spots barely matters any more, because the libraries are already fast and CPUs are extremely good at running bad code quickly; what is left is architecture.
Holds
"Optimize it later" would be safe advice only if every engineer already knew how to avoid the architectural mistakes that no later optimization can remove.
Holds
Traditional performance engineering methods are insufficient for the scale of modern AI datacenters and need new approaches.
Holds
Performance work used to mean half a day reading traces before writing a single fix, and language models have collapsed that step to minutes.
Holds
The code today’s models and agents write is very hard to follow: you get better performance without knowing why, and no way to fix it when it breaks.
Holds
Repeated rewrites are the correct answer under fast growth, because a system specified to scale forever would take so long to build that the company would die before it shipped.
Holds
AI did not create the bottlenecks in software delivery; it threw gas on processes everybody already knew were weak.
Holds
Most software rewrites fail and take longer than people expect them to.
Holds
A compiler that also serves an IDE has to be lazy and deferred throughout — a different way of building compilers from the one the textbooks teach.
Holds
A good tool raises the floor of what people can build without lowering the ceiling, and almost every tool quietly lowers the ceiling.
Holds
A new API framework that ignores how existing apps were historically built undermines its own introduction
Holds
A compiler that names every place a change breaks turns refactoring into fixing errors until the compiler stops shouting.
Holds
A programming language is not a compiler but an experience: editing, running, debugging and the runtime library all have to fit together as one cycle.
Holds
A speed difference between languages that share the LLVM backend measures the benchmark author, not the languages.
Holds
A language can keep changing without a Python-2-to-3 break, as long as code written under the old and the new rules can be mixed freely in one program.
Holds
Python is ugly: full of superfluous instructions kept since 1987 for legacy reasons, and its __init__ offends the sensibilities to the core.
Holds
Sharing code between classes via inheritance in Python tends to produce a bad experience.
Holds