ALL parts (new and old) are Shimano except the old crankset.
I don't know a whole lot about bikes, so please help me out.
Old specs:
27,5" wheels, 19" frame
shift levers (both): Altus M370, 3×9
derailleurs (both): Alivio M4000 (rear: direct, front: clamp)
brakes (both): M396 + SM-RT30 discs (160 and 180mm)
cassette: Acera 11-34 9s
crankset: Suntour XCT 42-32-22 175mm
Some pictures: https://postimg.cc/gallery/Zy6WwB7
99% of the time I use the bike in a city that's mostly flat. I'm going for Deore because it's not too expensive and I guess it's good enough for my needs. The list below is work in progress because I'm not sure if everything's compatible across the board. I'm definitely not sure about top/down/side swings.
rear shift lever: https://productinfo.shimano.com/en/product/SL-M4100-R
front shift lever: https://productinfo.shimano.com/en/product/SL-M5100-L
rear derailleur: https://productinfo.shimano.com/en/product/RD-M6000-SGS
front derailleur: https://productinfo.shimano.com/en/product/FD-M6025-L
cassette (11-36T): https://productinfo.shimano.com/en/product/CS-M771-10
crankset: https://productinfo.shimano.com/en/product/FC-M6000-2
chain: https://productinfo.shimano.com/en/product/CN-HG95
bottom bracket: https://productinfo.shimano.com/en/product/SM-BB52
by MarvTheSkeleton