/ˈmɛt(ə)l/

noun

A person's ability to cope well with difficulties; spirit and resilience.

1: vigor and strength of spirit or temperament

"the team showed their true mettle in the second half"

2: staying quality or stamina

equipment that proved its mettle

proved his mettle in battle

Similar: spirit, fortitude, tenacity, strength of character, moral fibre, steel

In software engineering, continuous integration is the practice of merging all developers' working copies to a shared mainline several times a day.