SF · Hardware · Field guide.
Your contract manufacturer will teach you things about your own product you did not want to know. Choose the one that teaches early and cheaply.
Local and large: the South Bay is home to some of the biggest electronics manufacturers on earth, including Sanmina, Flex, and Jabil. Their floors in San Jose and Fremont mostly serve larger customers, but their new-product-introduction (NPI) programs exist to catch companies at exactly your stage.
Local and small: the Bay Area still has independent assembly shops that take runs of hundreds. They cost more per unit and save it back in iteration speed: an engineer can drive to the line, look at the failure, and change the process the same day.
Overseas: for consumer volumes, most SF companies end up in Shenzhen or Southeast Asia, often through a broker or a platform like Fictiv. Go overseas when your design is stable and your volumes justify the tooling; going early is how you end up air-freighting scrap.
Who else at my stage and in my category do you build for? (Ask for two references and call them.)
What does your engineering review of my design look like before the quote? A CM that quotes without a DFM pass is quoting the rework too.
Who owns the tooling, and what happens to it if we leave?
What is your line-down charge when my parts are late?
Start local, scale out. The first three builds exist to teach you your product; the fourth exists to make money. Companies that offshore build one usually pay for the lesson twice.
Last verified Sep 2026. Named spots are starting points from community knowledge, not endorsements.