Learn Polish: Komputerowiec naprawił mój laptop. - The IT specialist repaired my laptop.

The suffix -owiec is added to the noun komputer to describe a person closely associated with that object. It is a very common way to derive agentive nouns, meaning "someone who works with or does X." Other common examples include sportowiec (athlete) and związkowiec (trade unionist).

Is komputerowiec the standard, formal job title for an IT specialist?

Not exactly. It translates well to "IT guy" or "computer guy." It's very common in everyday speech, but a more formal or professional term for an IT specialist is informatyk.

Why is it mój laptop here instead of mojego laptopa? I thought technology nouns act like animate nouns in the accusative case.

You have a great memory! In everyday spoken Polish, words for personal technology often take the animate accusative ending (like mojego smartfona or mojego laptopa). However, the strict standard grammatical form treats them as inanimate (mój laptop), which is what this sentence uses. Both are correct, but the inanimate form is safer for formal writing.

Why is the perfective verb naprawił used here instead of the imperfective naprawiał?

We use the perfective verb naprawił because the action was fully completed with a successful result: the laptop is now fixed. If you used the imperfective naprawiał, it would mean he was in the process of fixing it (and might not have finished) or that he used to fix it repeatedly.