Field notes · 17 June 2025
Image weight on catalogue screens that scroll forever
Why catalogue apps stall on mid-range devices and what we measure before blaming the network.
Catalogue and marketplace apps often feel fine on flagship phones and sticky on the devices most Thai shoppers carry. The culprit is rarely a single giant image—it is dozens of medium assets decoding while the list scrolls.
During audits we record decode time, memory peaks while flinging the list, and how often cells recycle with unfinished downloads. Those three numbers explain jank better than a single network waterfall screenshot.
Teams recover responsiveness by sizing assets to the cell, limiting concurrent decodes, and keeping placeholders light enough that empty cells do not flash white. Compression helps, but wrong dimensions undo the savings.
If your catalogue is the revenue path, put image discipline in the launch checklist beside crash budgets. Users abandon slow grids quietly; store reviews mention the feeling weeks later.