📰 Dev.to · Joe Lin

Why transparent PNGs turn white when you convert them to JPG in the browser

Why a precise image color picker needs two canvases (one to read pixels, one to draw the loupe)

Counting text is harder than it looks (especially once Chinese and emoji show up)

The hard part of an image cropper is keeping two coordinate systems from drifting apart

East Asian nominal age isn't just age + 1 (the real boundary is Lunar New Year)

Random pairing gets surprisingly tricky once you try to avoid repeats

Why pasted text keeps breaking search and formatting (and the regexes I ended up using to clean it)

The hard part of batch date conversion isn't formatting — it's deciding what `01/02/2024` means

The fastest part of this fuzzy duplicate finder is the comparison it never does

I thought masking PII for AI prompts was a regex problem — the restore step was the real design constraint

A batch file renamer looks simple until you have to decide what counts as “the filename”

The higher-paying offer can still lose — the exact assumptions in my job-offer comparator

A debt snowball vs avalanche slider sounds obvious — until you try to define 50/50 in code

Why this DCA vs lump-sum simulator caps a single month’s crash at 95%

Why “0% installments” and loans shouldn’t share the same formula (I only really got it after building a comparator)

Why signed binary ranges are asymmetric (I only really got it after building a converter)

Turns out "fancy Instagram fonts" are just Unicode — here's how I built a generator for it