A pioneer is a soldier employed to perform engineering and construction tasks. Wikipedia

An assault pioneer is an infantryman who is responsible for: The construction of tools for infantry soldiers to cross natural and man-made obstacles as well as breaching of enemy fortifications Supervising the construction of field defensive works such as bunkers, support weapon firing positions, etc. Wikipedia

A soldier employed for engineering and construction tasks Wikipedia Disambiguation

Soldier tasked with engineering and construction Wikidata

A soldier detailed or employed to form roads, dig trenches, and make bridges, as an army advances; a sapper. Wiktionary

Soldier. Wiktionary (translation)