Perseverant (adjective)
Enduring; persistent, resistant.
Persevering (noun)
perseverance
Persevering (adjective)
Tending to persevere.
Wiktionary
Perseverant (adjective)
persistent in doing something despite difficulty; unwavering
“you need to be spirited and perseverant to drive your projects through”
“if you have a perseverant mind, you will work until all problems are resolved”
Oxford Dictionary