I assume you meant in less than 1s. The alternative (for less than 1s) does not sound very attractive. I needed to take a picture today and the only thing I had to hand was my Jolla. It took at least 12 seconds(!) to start the camera. I admit I did not time it with a stopwatch but after I waited for what seemed like ages I started counting in my head: "One elephant, two elephants..." The 12s was only from the point when I started counting.
I have mentioned the mandatory 1 second app start time requirement often during this text. There is a reason: as said, there was no multitasking for QML apps in Meltemi. So I present you quite normal scenario: My friend sends me a text while I’m browsing a web page. I’ll swipe away the browser and go to recents where I tap on the notification. Wait 1 second to open messages app. Decide to reply with a photo. Tap on “attach” icon. Wait 1 second to start Gallery. Pick a photo. Gallery closes. Wait one second to load back the message editor (it got killed when I went to Gallery, remember?). Choose to add another recipient. Tap the plus icon. Wait one second for contacts. Choose a contact. Wait 1 second that editor reopens. Press send. Messaging closes. Swipe up for “multitasking bar”, tap on browser. Wait 1 second for browser to load. Continue from where you were. With proper transition animations those seconds are not as bad as they sound and the UI feels fluid.