In their support page, Nintendo has quietly posted that gamers cannot transfer the save games between their Nintendo Switch consoles. For example, if you decide to complete Legend of Zelda, then you should finish it on the system where you started.
According to the company, you can use a microSD card to save screenshots and software data, including downloaded software, software updates, and DLC. However, save game data are restricted to your system memory and you cannot save or copy them to a microSD card. This means, if your Switch breaks, or is lost, so is all of your hard work. And remember, the Switch internal memory is only 32GB, nearly a quarter of which is taken up by the OS.
If you run out space on the System Memory for your game save data, then you must delete your old saves to make room for new. You can free up space within System Settings > Data Management. Fortunately, Nintendo confirmed to Kotaku that you cannot transfer saves “at this time”, which leaves the door open to an upgrade, but it is far from a guarantee.
Either way, this is not a good news for gamers coming from virtually any other console, particularly a PS4 or Xbox One, where cloud saves are within easy reach.