Learn Polish: Proszę przedstawić swój dorobek bądź załączyć dokumenty. - Please present your achievements or attach the documents.

bądź is a highly formal disjunctive conjunction. It means exactly the same as albo or lub, but it is generally reserved for official documents, formal letters, and legal or academic texts. In everyday spoken Polish, you would use albo or lub instead.

Since this is a formal sentence, why do we use swój instead of a formal pronoun like Pana or Pani?

The reflexive pronoun swój always points back to the logical subject of the action. Here, the implied subject doing the action of przedstawić (presenting) is the person being addressed. Using swój sounds very natural because it emphasizes that they are presenting their own achievements, though using Pana or Pani would also be grammatically correct.

What case is dorobek in here, and how does its meaning differ from other words for 'achievements'?

It is in the accusative case as the direct object of przedstawić. Since it is an inanimate masculine noun, its accusative form looks exactly like its nominative form. While words like osiągnięcia mean individual achievements, dorobek specifically refers to the entire body of a person's work, such as a portfolio, track record, or lifetime output.

Why are both przedstawić and załączyć in the perfective aspect after proszę?