Comparison
BackpressurevsWork-in-progress limit
Backpressure
the consumer tells the producer to slow down rather than silently buffering work it cannot keep up with.
A mechanism by which a saturated component signals upstream to reduce its rate. The alternative is an unbounded buffer, which converts a throughput problem into a memory exhaustion problem and hides it until the process dies. Bounded queues that block or reject are the simplest form; explicit credit-based flow control is the sophisticated one.
Full entry →Work-in-progress limit
you were told to finish one of the four things you had started before picking up a fifth.
A cap on how many items may be in flight at once, per person or per team. It feels like a restriction and functions as a throughput improvement, because unfinished work delivers nothing while consuming attention, context and review capacity. It also makes bottlenecks visible immediately: when the limit is hit and nothing can start, the reason is the thing everyone was quietly working around.
Full entry →