They are also insanely expensive if you are used to China prices. Boards with 10-15 components being $100+ each. Couple that with a domestic PCB manufacturing which is ~10x the cost of China, you are looking at something like an Arduino costing $250.
Perhaps I'm missing something, but I haven't ever had to 'go over' the board with PCBWay. Maybe why they are so cheap, but I've only ever had one quality issue.
I send the gerbers and pick and place and take it from there. I approve photos If they have any question (which is rare) its over email. I don't even mind sourcing the parts/pcb/stencil myself. Its the components which make the tariff painful.
Great if you only need a few square inches.
https://www.emeraldtechnologies.com
If I remember correctly they were just over $200 per smartwatch. We saved some costs by putting the assembled boards into 3D printed cases ourselves using student labor:
https://amulet-project.org/2018/08/02/assmebly-of-new-amulet...
There's a list of the major components (MCU, BT radio, sensors, display, battery) here:
https://github.com/AmuletGroup/amulet-project/tree/master/ha...
Not including the student labor (or my labor) I think the total we spent per smartwatch ended up being about $300.
To get an idea of the complexity of the boards here's the open source Github repo with the hardware and software files:
https://github.com/AmuletGroup/amulet-project
It was a double sided, 4 layer board with two small sub-PCB's (touch pads and a power board I think). My experience with Emerald Technologies (then called DataEd at their New Hampshire location, seems they've been bought out by a larger firm) was very positive. They were quite helpful in bringing the project to completion.
https://circuitsassembly.com/ca/editorial/menu-news/33794-da...
The cost per board would have been less if we had ordered more of them. Ours was a fairly large job for DataEd at the time, though they would have been happy to make a thousand of the devices. For tens of thousands or more they would have recommended another affiliated company. They were more of a prototyping company, though that may have changed since the merger. I see that part of Emerald is located in China now, though the DataEd facility is still part of the company, so they might be interested in some US work to carry them through the tariff chaos.
Edit: I should mention, I supplied some of the parts that I prebought to lock in a supply, the MSP430's and touch sensor IC's for example, and they supplied the rest. We had them do minimal QA on the boards, without firmware loaded and we did final QA after programming the boards ourselves. They would have been willing to do those tasks also though.