Observed arrival · 2026-11-14
holdsup.dev: code under load
An interactive set of visual explanations for how algorithms, database queries, APIs, and server behavior change as data or traffic grows.
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ƒJS
- For
- Developers learning how code scales
- Worth noticing
- Its million-item sorting estimates assume 10 ns per step and put bubble sort at 1.39 hours versus radix sort at 140 ms.
Field notes
Controls let readers change the modeled input size and time per operation; the page also contrasts linear scanning, binary search, and hash lookup at a million rows. Its examples extend beyond runtime curves to an out-of-memory illustration comparing ten million in-memory rows with streaming, while the latency panel is explicitly labeled an illustrative trace rather than observed server telemetry.
Observed signals
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Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
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