A juzgar por la referencia laboral, tiene experiencia demostrable.

It means something like judging by or based on.

It is a very common fixed expression used to draw a conclusion from evidence:

• A juzgar por su acento, es de Sevilla. = Judging by his accent, he is from Seville.
• A juzgar por la referencia laboral, tiene experiencia demostrable. = Judging by the job reference, he/she has provable experience.

It often introduces the reason for your conclusion.

Because a juzgar por is a fixed expression built with the preposition a + the infinitive juzgar.

In Spanish, some expressions use an infinitive in this way:

• a decir verdad = to tell the truth
• a juzgar por = judging by
• sin contar = not counting / without counting

So here, juzgar is not acting like the main verb of the sentence. The main verb is tiene.

Here por means something like by or from, as in judging by/from.

It introduces the evidence you are using to make your judgment:

• A juzgar por su cara... = Judging by his face...
• A juzgar por los resultados... = Judging by the results...

So la referencia laboral is the basis for the conclusion.

Referencia laboral means a job reference, employment reference, or work reference.

It usually refers to a document, statement, or recommendation that confirms someone’s work history or performance.

In job-related Spanish, you may also see:

• carta de recomendación = letter of recommendation
• referencias = references
• historial laboral = work history

In this sentence, la referencia laboral suggests some formal evidence from a previous employer or job context.

It means verifiable experience, provable experience, or experience that can be demonstrated with evidence.

The adjective demostrable comes from demostrar = to show, prove, demonstrate.

In work and CV contexts, experiencia demostrable often means the person can actually back up their claimed experience with:

• references
• documents
• previous jobs
• concrete results

It is a common phrase in professional Spanish.

Spanish often leaves out the subject pronoun when it is clear from the verb form or the context.

• tiene already means he/she has
• Spanish does not need to say él or ella unless there is special emphasis or contrast

So:

• Tiene experiencia demostrable = He/She has demonstrable experience

This is very normal in Spanish and happens constantly.

Because Spanish often omits the article when talking about something in a general or indefinite way.

Here, tiene experiencia demostrable means he/she has demonstrable experience in a general sense.

Compare:

• Tiene experiencia demostrable. = He/She has demonstrable experience.
• Tiene la experiencia demostrable que exige el puesto. = He/She has the demonstrable experience the position requires.

The version without la sounds more natural here because it is just stating a general quality.

Yes. In Spanish, most descriptive adjectives normally come after the noun.

So:

• experiencia demostrable
• referencia laboral

This is the standard order.

If an adjective comes before the noun, it often changes the tone, meaning, or emphasis. But with demostrable, the normal and natural position is after experiencia.

Sometimes, but not always.

• A juzgar por = judging by / based on the evidence of
• según = according to

They are close, but not identical.

Compare:

• A juzgar por la referencia laboral, tiene experiencia demostrable.
  This means the speaker is making a conclusion from the reference.

• Según la referencia laboral, tiene experiencia demostrable.
  This means according to what the reference says, he/she has demonstrable experience.

So según reports information more directly, while a juzgar por emphasizes the speaker’s inference.

Yes, it sounds fairly formal or professional, especially because of:

• referencia laboral
• experiencia demostrable

These are common in workplace, HR, and recruitment contexts.

In everyday conversation, people might say something simpler depending on the situation, but this sentence sounds natural in professional Spanish from Spain.