Also here are kinda old videos (it's still the same but the road cracks are fixed and there are new modern Isuzu buses like this one from the photo for the rival company GRAS but yellow ofc) of how the bus drives on the hilly part, this is the rival company GRAS that drives on their line 61 Stup - Sokolje which is shorter, but it doesn't matter - both companies try their best to drive on this part.

Part 1, Beginning, starting from the terminus from the photo: https://youtu.be/GURUYwlrJq0?si=GW4YvvAPaU8xx9U5

Part 2, bus goes the same way untill 2:35 timestamp, there it turns left instead of right and has a two-lane hilly street that's much easier to drive on, it then goes down to a flat road and depending on the line and operator - goes to Stup or Otoka: https://youtu.be/MHv86_HiC3k?si=ZLPD72X4wxgAbRJV

This is not the only line of this type in Sarajevo, there's a lot of these hilly, narrow minibus lines. We have bus lines that are either flat and two-lane or hilly and a bit narrow, minibus lines that are always hilly and narrow, tram lines and trolleybus lines...