Definition
Plain language
Multiple things happening at the same time inside a program, which can produce bugs that depend on the exact order.
As stated in the literature
A programming regime where multiple threads or processes can execute interleaved or simultaneously, often producing bugs visible only under specific interleavings.
Why it matters: Concurrency bugs are notoriously hard to find with normal testing, which makes them a high-value target for both AI agents hunting for vulnerabilities and AI tools writing safer code.
For example, two threads both check 'is the file open?' at once, both see 'no,' and both try to open it, producing a bug that only shows up under load.
Heard on the show
“… asynchronous, when the agent wants to launch three children in parallel it just uses ordinary Python concurrency — asyncio dot gather, the same thing any working Python developer reaches for. …”Episode 028 — Teaching a Model to Hire Copies of Itself: Recursive Agent Optimization