Wir ordnen Metadaten dadurch, dass wir das Aufnahmedatum ergänzen.

Dadurch, dass means something like by the fact that or, more naturally in English, by doing this / through the fact that. It introduces the means or method by which something is done.

So in this sentence, Wir ordnen Metadaten dadurch, dass ... means that the metadata is organized by adding the recording date.

• weil means because, so it gives a reason, not a method.
• indem often means by doing, and it can be a good alternative here.

For example:

• Wir ordnen Metadaten, indem wir das Aufnahmedatum ergänzen.

That is very close in meaning.
The version with dadurch, dass is slightly more explicit and a bit heavier in style.

Because dass introduces a subordinate clause, and in German subordinate clauses are separated from the main clause by a comma.

Here the structure is:

• Main clause: Wir ordnen Metadaten dadurch
• Subordinate clause: dass wir das Aufnahmedatum ergänzen

German punctuation requires that comma.

Because dass creates a subordinate clause, and in German subordinate clauses the conjugated verb normally goes to the end.

Compare:

• Main clause: Wir ergänzen das Aufnahmedatum.
• Subordinate clause: ..., dass wir das Aufnahmedatum ergänzen.

This is one of the most important word-order rules in German.

On its own, dadurch usually means through that, by that, or as a result depending on context.

In dadurch, dass, it works together with dass as a fixed pattern. You can think of it as a two-part connector:

• dadurch = points forward to the method/result
• dass = introduces the clause that explains it

So dadurch, dass wir das Aufnahmedatum ergänzen literally means something like through the fact that we add the recording date.

Because Metadaten is being used in a general sense, not referring to specific metadata items already identified.

German often omits the article with plural nouns when speaking generally:

• Wir ordnen Metadaten. = We organize metadata.

If you wanted to refer to specific metadata, you could say:

• Wir ordnen die Metadaten. = We organize the metadata.

So the absence of the article here is normal.

It is in the accusative case, because it is the direct object of ordnen.

• wir = subject
• ordnen = verb
• Metadaten = thing being organized, so direct object

With Metadaten, nominative and accusative look the same because it is a plural noun. So you identify the case from the sentence role, not from the form alone.

Because Aufnahmedatum is a neuter noun, so its article is das.

In the sentence, it is also the direct object of ergänzen, so it is in the accusative. For neuter nouns, nominative and accusative singular use the same article:

• nominative: das Aufnahmedatum
• accusative: das Aufnahmedatum

So the form stays das.

It is a compound noun:

• Aufnahme = recording, capture, intake, depending on context
• Datum = date

So Aufnahmedatum means recording date or date of recording.

German forms many nouns by combining smaller nouns like this, and the final part determines the grammatical gender. Since Datum is neuter, Aufnahmedatum is also neuter.

Here ergänzen means to add, to supplement, or to fill in something that was missing.

So das Aufnahmedatum ergänzen suggests that the recording date is being added to metadata that does not yet contain it.

It is slightly different from just hinzufügen:

• hinzufügen = add something
• ergänzen = add something in order to complete or improve what is already there

So ergänzen fits well if the metadata already exists and you are making it more complete.

Ordnen means to arrange, to sort, or to organize.

In this sentence, it suggests putting metadata into order or making it more systematically organized. Depending on context, English might translate it in different ways:

• organize
• sort
• arrange

It is a perfectly normal verb, though in technical contexts German might also use verbs like:

• strukturieren = structure
• sortieren = sort
• organisieren = organize

So ordnen is correct and natural, with a slightly general sense of putting in order.

Yes. A very natural alternative is:

• Wir ordnen Metadaten, indem wir das Aufnahmedatum ergänzen.

This means almost the same thing: We organize metadata by adding the recording date.

A rough difference:

• indem is often the most direct way to express by doing X
• dadurch, dass is a bit more explicit and sometimes feels slightly more formal or heavier

Both are grammatically correct here.

Yes. You can front the subordinate part:

• Dadurch, dass wir das Aufnahmedatum ergänzen, ordnen wir Metadaten.

This is also correct.

Notice what happens in the main clause after the fronted subordinate clause:

• the verb still comes second: ordnen
• the subject follows it: wir

That is because German main clauses follow the verb-second rule.

It could say that. German often has more than one way to express the same idea.

For example:

• Wir ordnen Metadaten dadurch, dass wir das Aufnahmedatum ergänzen.
• Wir ordnen Metadaten, indem wir das Aufnahmedatum ergänzen.
• Wir ordnen Metadaten durch das Ergänzen des Aufnahmedatums.

The version with durch das Ergänzen des Aufnahmedatums is more nominal and more formal or technical in style.
The original sentence is more verbal and usually easier to process.

Here it points forward to the explanation introduced by dass.

In some German sentences, dadurch can refer back to something already mentioned. But in the pattern dadurch, dass ..., it acts as a kind of placeholder that announces: the way this happens is the following.

So in this sentence, dadurch does not stand alone semantically; it is completed by the dass clause.

Because the dass clause is a full clause of its own, and full clauses need their own subject unless the subject is omitted for some special reason.

So:

• main clause subject: wir
• subordinate clause subject: wir

That is completely normal in German, just as in English:

• We organize metadata by the fact that we add the recording date.

Even though the subject is the same in both parts, German still states it again.

It sounds mostly neutral to somewhat formal, especially because of dadurch, dass and the technical noun Metadaten.

In everyday conversational German, many speakers would probably prefer the simpler:

• Wir ordnen Metadaten, indem wir das Aufnahmedatum ergänzen.

or even something more direct depending on context.

So the original sentence is not unnatural, but it does sound a bit more written or explanatory than casual spoken German.