Where does “отслеживать” come from?

отслеживать (Russian) comes from Russian отследи́ть, from Russian от-, from Proto-Slavic otъ-.

Ancestry of “отслеживать”, step by step

Step	Language	Word	Meaning
1	Russian	отследи́ть	—
2	Russian	от-	away from
3	Proto-Slavic	otъ-	—

отслеживать — Etymology, Origin & Word History | Etymology Explorer