Imagine having a surface mount kit that you’d like to stencil with solder paste and reflow solder, but which doesn’t come with a solder stencil. That was what faced [Honghong Lu], and she rose ...

To successfully complete it you need to solder both a resistor and an LED in 1206, 0805, 0603, 0402, and 0201 packages. Those oh-two-oh-ones are basically grains of sand… good luck with that!