SALO, Finland—When San Diego-based Nuviz Inc. started developing high-tech head-up displays for motorcyclists, it turned last year to this provincial Finnish city long known as Nokia Town.

In under a week, Nuviz executives found and hired 20 engineers in Salo, home to some 50,000 residents. The team recently finished developing a fully functional display prototype, taking less than six months.

Salo, the birthplace of the cellular phone, took a body blow when Nokia Corp. abandoned mobile-device manufacturing, selling its cellphone assets to Microsoft Corp. for €5.44 billion ($5.86 billion) to focus on network equipment. The city’s future darkened further when Microsoft decided to shrink its mobile-phone operations and laid off its last Salo workers earlier this year.

But now prospects are brightening, as Salo draws a steady stream of tech companies looking to make use of what Nokia and Microsoft left behind: scores of experienced engineers and vast areas of idled factories.

“It’s a pool of people you can’t find in California,” said Marcel Rogalla, one of Nuviz’s founders. “They’re 100% productive, right from the start.”