Контактный центр работает ночью.

Because контактный is an adjective agreeing with центр.

In Russian, adjectives must match the noun they describe in:

• gender
• number
• case

Here, центр is:

• masculine
• singular
• nominative

So the adjective also has to be masculine singular nominative:

• masculine: контактный
• feminine: контактная
• neuter: контактное

So контактный центр means contact center with full grammatical agreement.

Центр is in the nominative case.

It is the subject of the sentence — the thing doing the action:

• Контактный центр = the contact center
• работает = works / is operating

In a basic Russian sentence, the subject is usually in the nominative case.

Because the subject is singular.

• центр = one center
• so the verb must also be singular: работает

Compare:

• Контактный центр работает. = The contact center works.
• Контактные центры работают. = Contact centers work.

Russian verbs in the present tense change depending on the subject’s person and number.

Here работает means something like:

• works
• is operating
• is open
• is functioning

With businesses, services, machines, systems, etc., работать often means more than just to do work.

So for a place or service, работает ночью usually means it is operating at night or open at night, not that the building itself is literally doing labor.

Because ночью is the form used to mean at night / during the night.

It is the instrumental singular form of ночь:

• nominative: ночь
• instrumental: ночью

Russian often uses certain nouns in the instrumental case as adverbial time expressions. So:

• ночью = at night
• утром = in the morning
• днём = in the daytime / during the day
• вечером = in the evening

So работает ночью is a very natural way to say works/is open at night.

It can mean either, depending on context.

In this sentence, Контактный центр работает ночью, it most naturally suggests a general fact:

• the contact center operates at night
• the contact center is open at night

But ночью itself does not always force a repeated meaning. It can also refer to a particular night if the context makes that clear.

If you want to strongly emphasize habitual repetition, Russian often uses:

• по ночам = at nights / night after night / habitually at night

So:

• работает ночью = works at night
• работает по ночам = works at night regularly / nights in general

Because Russian has no articles.

English uses:

• a
• an
• the

Russian does not. So контактный центр can mean:

• a contact center
• the contact center

Which one is meant depends on the context.

That is completely normal in Russian, and learners have to get used to understanding definiteness from the situation rather than from an article.

Yes. Russian word order is more flexible than English word order.

The neutral order here is:

• Контактный центр работает ночью.

But you could also say:

• Ночью контактный центр работает.
• Работает контактный центр ночью.

These versions may sound different in emphasis, but the basic meaning stays similar because the case endings help show each word’s role.

Still, the original sentence is the most straightforward, neutral way to say it.

Yes, it is a normal modern expression.

You may also see:

• контакт-центр

That hyphenated spelling is also common in modern Russian, especially in business language.

So both of these may appear:

• контактный центр
• контакт-центр

The sentence you were given uses the fully inflected adjective + noun structure, which is very useful for learners because it clearly shows agreement.

Russian present tense often covers both English simple present and present progressive.

So работает can correspond to:

• works
• is working

The exact English translation depends on context.

In this sentence, the most natural idea is usually a general fact:

• the contact center works / is open at night

But Russian does not need a separate form like English is working here.

A helpful stress pattern is:

• конта́ктный центр рабо́тает но́чью

A few notes:

• конта́ктный has stress on the second syllable
• рабо́тает has stress on бо
• но́чью has stress on the first syllable

If you are reading aloud, say it smoothly as one sentence: конта́ктный центр рабо́тает но́чью

Indirectly, yes — but grammatically the subject is still the contact center, not the employees.

Russian often talks about organizations or places as if they work:

• a store works
• a website works
• a service works

So the sentence primarily means the service/center operates at night. From that, it may naturally follow that staff are working then too, but that is not the literal grammatical subject of the sentence.