Kıdem bilgisi sözleşmede yazıyor.

In this sentence, kıdem usually means seniority, length of service, or tenure in a work context.

So kıdem bilgisi is information related to a person's seniority at work, not general personal background information.

Because kıdem bilgisi is a very common Turkish structure called an indefinite noun compound.

Pattern:

• Noun + noun-(s)I

So here:

• kıdem = seniority
• bilgisi = its information / information of it

But in English, you usually translate the whole thing more naturally as:

• seniority information
• information about seniority

Important point: The -si on bilgisi does not necessarily mean real possession here. It is just the normal marker used in this noun-compound pattern.

Compare:

• öğrenci kartı = student card
• telefon numarası = phone number
• kimlik bilgisi = identity information

Because kıdem bilgisi is the compound form, which is the normal way to say seniority information.

If you say kıdemin bilgisi, that uses the genitive ending -in on kıdem, and it sounds more like:

• the information of the seniority
• a more specific, more possessive relationship

In most everyday cases, Turkish prefers the compound:

• kıdem bilgisi

So for an English speaker, it helps to think:

• kıdem bilgisi = the usual dictionary-style combination
• kıdemin bilgisi = more specific, less neutral, and usually less natural here

-de is the locative case ending. It means in, on, or at, depending on context.

So:

• sözleşme = contract
• sözleşmede = in the contract

Why -de? Because Turkish adds a locative ending that changes by vowel harmony and consonant voicing:

• -de / -da / -te / -ta

Here it becomes -de.

Yes, literally yazıyor is the present continuous form of yazmak, so it often means is writing.

But with things like:

• signs
• labels
• documents
• screens
• notices
• text

Turkish often uses yazıyor to mean:

• it says
• it is written
• it appears in writing

So in this sentence, yazıyor does not mean that the information is actively writing something. It means the information is written there / appears there.

This is a very common Turkish usage.

No. Turkish does not have articles like English the and a/an in the same way.

So:

• kıdem bilgisi can mean seniority information or the seniority information
• sözleşmede can mean in the contract

The exact interpretation depends on context.

If Turkish wants to emphasize a/an, it can use bir:

• bir sözleşmede = in a contract

But in your sentence, Turkish just leaves that unstated.

The sentence is:

• Kıdem bilgisi = subject
• sözleşmede = location
• yazıyor = verb

So the structure is basically:

• Subject + place + verb

That is very normal in Turkish.

Turkish word order is flexible, though. You could also say:

• Sözleşmede kıdem bilgisi yazıyor.

That version puts more attention on where the information is written.

In both versions, the verb usually stays at the end.

Yes. That is also natural, and in some contexts it may sound even more literally like is written.

Difference in feel:

• yazıyor = it says / it is written there / it appears there
• yazılı = written, in written form

So:

• Kıdem bilgisi sözleşmede yazıyor. = The contract says / contains the seniority information.
• Kıdem bilgisi sözleşmede yazılı. = The seniority information is written in the contract.

Both are possible, but the nuance is slightly different.

Yes. That would also be understandable and natural.

Nuance:

• ... yazıyor focuses on the fact that it is written
• ... var focuses on the fact that it exists / is present
• ... yazılı focuses on the state of being written
• ... yer alıyor is a more formal option meaning is included / appears

So these are all related, but not identical:

• Kıdem bilgisi sözleşmede yazıyor.
• Kıdem bilgisi sözleşmede yazılı.
• Kıdem bilgisi sözleşmede var.
• Kıdem bilgisi sözleşmede yer alıyor.

Not in this sentence, because yazıyor is already a full verb.

So this is not:

• subject + adjective + hidden is

It is:

• subject + place + verb

However, if you used yazılı, then Turkish would often have a zero copula in the present tense:

• Kıdem bilgisi sözleşmede yazılı.

That means:

• The seniority information is written in the contract.

In more formal Turkish, you might also see:

• Kıdem bilgisi sözleşmede yazılıdır.

So:

• yazıyor = full verb
• yazılı = adjective-like form, often with an unspoken is

A rough guide:

• ı in kıdem and yazıyor: a vowel with no exact English equivalent. It is a back, unrounded vowel. You can think of it as a short, relaxed uh sound, but without rounding the lips.
• ö in sözleşmede: like German ö or French eu. There is no perfect English match.
• ş in sözleşmede: like English sh

Very rough pronunciation:

• kıdem ≈ kuh-dem
• bilgisi ≈ bil-gi-si
• sözleşmede ≈ söz-leş-me-de
• yazıyor ≈ ya-zı-yor

That is only approximate, but it helps at the beginning.