It used to be a lot of them roaming in the residential area, out of necessity since household items were precious. Related is also the profession of a tinker to mend woks and pots and the scissor sharpener https://donwagner.dk/tinkers/tinkers-Zhongwen.html

Used to hear their shout in the street but largely disappeared in the 90s.

The article mentions it -

>> But Ju ci is more than a technique; like its close cousin, Kintsugi (the Japanese art of repairing broken ceramics using lacquer and gold), Ju ci embraces a profound philosophy: that of celebrating “beauty of the imperfect.”