Preservamos el archivo digital sin que falten los metadatos.

Because sin que is followed by a conjugated verb, and in this kind of sentence Spanish normally uses the subjunctive.

• sin que falten los metadatos = without the metadata being missing
• sin faltar would not sound natural here for this meaning.

A useful pattern to remember is:

• sin que + subjunctive

For example:

• Lo hizo sin que nadie lo viera. = He did it without anyone seeing him.
• Salieron sin que yo lo supiera. = They left without me knowing it.

So in your sentence, falten is there because sin que triggers the subjunctive.

It is in the subjunctive because it comes after sin que, which usually introduces something that is prevented, avoided, or not allowed to happen.

Here the idea is:

• We preserve the digital file in such a way that the metadata does not end up missing.

Spanish expresses that with:

• sin que falten los metadatos

If you used the indicative (faltan), it would sound ungrammatical in standard Spanish after sin que.

Because the subject of falten is los metadatos, which is grammatically plural.

• el metadato → singular
• los metadatos → plural

So the verb must agree with it:

• que falte el metadato
• que falten los metadatos

Even though English metadata is often treated like an uncountable noun, in Spanish metadatos is normally plural.

Here faltar means to be missing or to be absent, not to miss in the emotional sense.

So:

• faltan los metadatos = the metadata are missing / the metadata is missing

This verb is very common in Spanish for expressing lack or absence:

• Falta sal. = There is no salt / Salt is missing.
• Faltan dos páginas. = Two pages are missing.

In your sentence, the idea is that the file is preserved without any metadata being missing.

Spanish often uses the definite article more than English does.

Here los metadatos sounds natural because it refers to the metadata associated with that file, not just metadata in a vague abstract sense.

Compare:

• Faltan metadatos. = Metadata is missing.
  
  • more indefinite, less specific
• Falten los metadatos. = the metadata is missing
  
  • more specific, referring to the expected metadata

In this sentence, los metadatos suggests the metadata that should belong to that digital file.

Preservamos is the 1st person plural present indicative of preservar.

It means:

• we preserve
• sometimes, depending on context, we are preserving

In many contexts, the Spanish present tense can express:

• a habitual action: we preserve
• a current action: we’re preserving
• a general procedure: we preserve

So the sentence could describe a regular process, a policy, or what we do in a specific context.

Usually archivo can mean either file or archive, depending on context.

In this sentence, archivo digital most naturally sounds like:

• digital file

But in some technical or institutional contexts, it could also suggest:

• digital archive
• archival record

A learner should know that archivo is broader than English archive alone. Very often in everyday computing, archivo simply means file.

Because in Spanish, adjectives usually come after the noun.

So:

• archivo digital = digital file
• documento importante = important document
• copia completa = complete copy

Putting the adjective after the noun is the normal order. Sometimes Spanish puts adjectives before the noun for style or emphasis, but not usually here.

Possibly, but the meaning would shift slightly.

• preservamos = we preserve, protect, keep intact
• conservamos = we keep / conserve / maintain
• guardamos = we keep / store / save

In a technical, archival, or preservation context, preservamos is a strong choice because it suggests maintaining the file and its integrity over time.

If you said guardamos el archivo digital, that would sound more like simply storing it.
If you said conservamos el archivo digital, that could also work, but it may sound slightly less specialized than preservamos.

Because Spanish usually leaves subject pronouns out when the verb ending already shows who the subject is.

• preservamos already tells you the subject is nosotros/nosotras = we

So:

• Preservamos el archivo digital... = We preserve the digital file...

You could say Nosotros preservamos..., but it is not necessary unless you want emphasis or contrast.

For example:

• Nosotros preservamos el archivo digital; ellos lo eliminan.
  = We preserve the digital file; they delete it.

It is mostly expressing manner or the condition under which the action is done.

The idea is:

• We preserve the digital file in such a way that no metadata is missing.
• We preserve the digital file without any metadata being missing.

So sin que falten los metadatos explains how the preservation is carried out, or what undesired situation is avoided.

It is not exactly purpose in the same way as para que no falten los metadatos, which would mean:

• so that the metadata will not be missing

That version sounds more clearly like purpose.

Yes, but the meaning changes slightly.

• sin que falten los metadatos = without the metadata being missing
• para que no falten los metadatos = so that the metadata won’t be missing

The original focuses on the absence of a problem during the preservation process.
The para que version focuses more directly on the goal or intention.

So both are possible in the right context, but they are not identical.

In standard Spanish, metadatos is normally used in the plural.

So you will usually see:

• los metadatos
• faltan metadatos
• los metadatos del archivo

You may occasionally see singular-like treatment in highly specialized or influenced contexts, but for learners, the safe and natural choice is:

• metadatos = plural noun

That is why the sentence uses falten, not falte.