Lab
Instruments you can drag
Mechanisms I had to understand properly to build the systems in Work — rebuilt as things you can poke at. Free, no signup, no email gate. If one of them saves you an afternoon, it did its job.
What k actually controls in Reciprocal Rank Fusion
Every hybrid search stack ships k = 60 and almost nobody can say what it does to their rankings. Drag k across two real ranked lists and watch the fused ordering reorder — including the point where the top result flips.
Answers: why k = 60, and when it is wrong for you
Why free memory looks fine while the machine is thrashing
Almost every memory alert in production is a threshold on free bytes, and it keeps missing the outages. Drag the threshold across three workloads and find the value that handles all of them — there isn't one, and the reason is that free bytes measures the wrong kind of quantity.
Answers: why your free-memory alert never fires in time