The general rule to follow when it comes to stir fry veggies is: thicker and harder first. Denser vegetables such as carrots and aubergine require more cooking time than green leafy vegetables like spinach or pak choy.
I prefer when vegetables are crunchy so I tend to slightly undercook them. Feel free to add a couple of minutes if you like them softer.
First:
Onion
Garlic
Ginger
Then:
Carrots
Bell peppers
Mushrooms
Asparagus
Edamame
Broccoli
To finish:
Snow peas
Leafy greens (spinach, kale, pak choi, etc.)
Courgette
I hope this helps!