It may be that the return of sunshine to southern Maine is causing unwarranted optimism, but it sure seemed like good news to hear that a Boston-based technology firm is opening a customer service center in Lewiston.

Carbonite Inc., which sells online computer and file backup systems, plans to start its Maine operation this summer, employing about 150 people.

Carbonite has been named one of the fastest-growing firms in the nation, and company officials have said Maine is an attractive place for high-tech expansion because of its stable, educated pool of workers and their reputation for having a strong work ethic.

The Lewiston call center will replace one in India, where the employees earned about one-third of what is envisioned for Maine, but could not produce the quality customer service that company officials anticipate getting from workers here. These are good jobs, some paying as much as $50,000 a year, and they will require some technical know-how.

Carbonite projects that its work force could quickly grow to 250, which is welcome news even though it barely scratches the surface of Maine’s jobs deficit. According to the state Department of Labor, Maine ended 2010 with 55,273 unemployed people.

The state unemployment rate for the year was 7.9 percent, but was far worse outside southern and coastal counties. Androscgogin County, where Carbonite is headed, had an 8.7 percent unemployment rate, and in neighboring Oxford it was 10.2 percent.

It will take a lot more than one new enterprise to take a real bite out of unemployment in Maine. But success for Carbonite could be a sign that after a long economic downturn, some sunlight is peeking through the clouds.