Concurrency & Parallelism
What "at the same time" actually means on real hardware, and the bugs that only exist because of it.
5 topics
Processes, threads, and async I/O
Three ways to overlap work, what each actually costs, and why a single-threaded runtime can still serve thousands of connections.
core25 minRace conditions and atomicity
Bugs whose existence depends on timing, why single-threaded JavaScript has them anyway, and what makes an operation safe to interleave.
core25 minLocks, deadlock, and contention
Mutual exclusion is the blunt fix for shared state, and it introduces its own failure modes — deadlock, contention, and lost throughput.
deep20 minBackpressure and bounded queues
When a producer outruns a consumer something must give, and choosing what gives is the difference between graceful degradation and a memory-exhaustion crash.
core25 minConcurrency Models
The four ways systems run more than one thing at once, and why JavaScript picked the one it did.
core25 minshared