The connection
Fibre to a flat is normal. People pay roughly 150,000–250,000 dong a month for a home line that will carry video calls. Confirm it is installed before you sign, not “available in the building”. A Viettel SIM is the straightforward backup: buy it at the airport or a shop with your passport, and use it when the cafe Wi-Fi folds during a call.
Where the laptop actually goes
An Thuong is the easy circuit. Coffee in that grid often lands around 35,000–60,000 dong. You can work a morning in one place. You should not assume a power socket, a quiet corner, or that anyone wants you on a three-hour call. Headphones. One drink an hour is the polite version. Coworking exists if you need a door that closes. The partner list on the city page includes a desk we have not personally sat at. Use it as a lead, not a vouch.
The day
The beach is the reason a lot of people pick Da Nang over a cheaper inland city. It is also the reason the work day slips. A swim before calls, or after, works. A swim instead of the call does not. Rainy weeks in the autumn are when the cafe plan earns its keep.
Time zones: Europe in the afternoon, the US late evening. Da Nang does not fix that. It just makes the morning yours.