Just Abit confuse what value does zerodha adds which the nest didn't?
Zerodha provides an offline basket order execution so that I can place an order via browser. Since browsers can operate anywhere, you can place orders from any platform.
I currently use google compute for auto placing orders at 9:15:00 even when not available
Just For hardcore linux ppl who dont have windows for nest or dont want to run it
I run only on Linux
Just use any broker who provides you an interface with browser.
Zerodha provides them (Upstox should also provide it but got to check)
Else you need to use an API but API's are costly for retail traders, in my opinion. If you have an extremely well tested scalping strategy, you can use it.