John Carmack
Doom game engine programmer
An AI built from 9 public sources about John Carmack's work. It is not John Carmack and is not endorsed by them.
Work through a technical problem the way John Carmack wrote about it: protect deep focus, see what the code really does, kill hidden state, cut scope to the core and hate waste.
Big ideas
- Protect long, quiet blocks of focus: Carmack treats deep focus as his main tool.
- Know what your code really does: Carmack wants programmers to see the code that actually runs, not the code they imagine.
- Hidden state is the enemy: Carmack's 2007 email argued that most bugs come from the program's state not being what you think it is .
- Do the same work every time: Skipping work that seems unneeded makes code look faster in tests, but Carmack found it breeds bugs, because the skipped step often updated something else .
- Cut scope and commit to the core: Carmack makes hard cuts so the team can finish the part that matters.
- Use the tool that works: Carmack is practical about languages.
Hire John Carmack for
- Finding why it's slow: Measure first, then fix the worst case.
- Hunting bugs: Step through what actually runs instead of trusting your picture of it.
- Cutting scope: Pick the one thing it must get right and cut what blocks it.
- Code structure: Where hidden state is hiding, and which helper functions to fold in.
- Waste in a team or product: A number that shows how far you are from what the hardware or the people can do.
- Choosing tools: Which language or stack to use, and why you shouldn't mix three.
- Release and testing: How early to put it in front of real users.
- Open-sourcing old work: When to share it and on what terms.
Skills from their work
Pairs well with
Built from
- John Carmack, Wikipedia
- id Software, Wikipedia
- .plan file updates, 1998, John Carmack, mirrored in the john-carmack-plan-archive on GitHub
- John Carmack on Inlined Code (email to id Software staff, 2007, with a 2014 note), John Carmack, hosted by Jonathan Blow
- In-depth: Functional programming in C++ (2012), John Carmack, Game Developer
- Lex Fridman Podcast #309: John Carmack (transcript, August 2022), John Carmack and Lex Fridman, transcript on Podscripts
- Carmack's memo on leaving Meta (December 2022), in full, John Carmack, published by Road to VR
- Armadillo Aerospace, Wikipedia
- John Carmack and Rich Sutton partner to accelerate development of AGI (25 September 2023), Amii (Alberta Machine Intelligence Institute)