A great place for both indoor and outdoor working. The cafe is a popular spot for studying and working, but it is large so you can still find a seat most of the time. Fast WiFi, but power outlets are a bit difficult to find. I would say the biggest downside is that they close quite early.
I spent a day exploring Kita-Senju and this was my first stop. A large cafe not too far from the station. Very friendly staff. Unfortunately the menu doesn't have any tea. The walnut banana bread was very good. Excellent WiFi, but I didn't really see any power outlets (at least not at the large tables).
A cafe with delicious pastries and comfy counter seats. The WiFi was a bit slow, but still usable. I was able to take a call as well without much issues.
The cafe is very spacious but lacks seats for people who are alone. I felt bad for occupying the whole table for four seats. Anyhow, despite the google maps reviews saying that the WiFi is bad, I didn't have much problem at all. I ran a few speedtests and the fastest it recorded was 180 Mbps. However, there were some tests that scored around 30 Mbps, so I have to say it wasn't consistent. The music is really quiet. There are a few outdoor seatings for the smokers as well. Power outlets, you gotta find a good seat that's close to it.
A nice cafe near Seolleung station. The interior is quite spacious with plenty of natural light. Very fast WiFi and lots of power outlets. Usually not too busy, although it fills up a bit around lunch time. The only downside is that the nearest restroom is in the office building two doors down, which is a little inconvenient.
This library has plenty of seats and outlets to choose from. There are quite a few people working with their laptops open so seems like a normal thing to do. Wifi is not the fastest but stable. One thing that was annoying is that they probably block ports other than 80 or 443, so you can't SSH, connect to Postgresql DB, connecting to VPN, etc. For taking calls, if you go towards the kids area, you might feel more comfortable talking since there are kids who are also loud. However, there are signs that says no loud talking on the phone so not the best place when you have a day full of meetings. The out door benches are also available and the wifi speed doesn't drop too much even if you're seated outside. There's a supermarket right next to it so you can go grab some drinks if you need any. Edit - I could bypass the restriction by using Obfuscated Servers with Open VPN (TCP) protocol on NordVPN.
A very cozy and trendy cafe near Chiang Kai-Shek memorial hall. They open early (7:30) so it's a great spot to get an early start to your day. There's an extensive selection of drinks and desserts. If you're a group then you'll want to arrive early to get the large worktable. For solo-working I like the counter-style seats along the wall, although the table space might be a little small if you have a larger laptop. There's power but you may need to unplug a lamp. The cafe usually gets quite busy, and the staff may impose a 3 hour time limit.
A spacious cafe along the riverside in Tamsui. The first floor has indoor and outdoor seating, and the 2nd floor has a large terrace with covered and uncovered seats offering great views of the river or to catch the sunset on a clear day. During the afternoon on a weekday it was fairly quiet, but it started to fill up towards the evening time. They have both a large food and drink selection. Note that the upstairs terrace didn't open until 3pm (I'm not sure if that's always the case). Decent WiFi and power outlets. Note that the men's restroom doesn't have any western style toilet. I'm not sure about the women's.
Star Rocket Café is located on the 11F of the Syntrend department store. On a weekday it's very suitable for working, as it's usually quiet and plenty of seats. The large worktable in particular is comfortable and good for working. They offer basic food and drinks. The drawbacks are that the WiFi is a little slow and disconnects occasionally, and the opening hours are quite short. Extension cords are available if you ask the staff.
To reach the cafe, enter the main entrance, take a right and find the elevators. Take the elevator up to the 11th floor and follow signs for the Star Rocket Cafe.