Learn French: Il a optimisé le processus, de sorte que l'équipe a fini plus tôt. - He optimized the process, so that the team finished earlier.

De sorte que can take either the indicative or the subjunctive depending on its meaning in the sentence. Here, it describes a factual result: the team actually did finish earlier. When de sorte que introduces a real consequence or result, it takes the indicative.

How would the meaning change if the subjunctive were used instead?

If the sentence used the past subjunctive (de sorte que l'équipe ait fini plus tôt), it would express a goal or purpose rather than a guaranteed result. It would translate to 'in order that the team might finish earlier,' leaving it uncertain whether they actually achieved that goal.

Could I use pour que instead of de sorte que in this sentence?

Not without changing the meaning and the grammar. Pour que always means 'so that' in the sense of a goal or purpose, and it always triggers the subjunctive. Because this sentence is stating a factual result rather than an intention, de sorte que with the indicative is the correct choice.

Why is the result expressed in the passé composé (a fini) rather than the imparfait (finissait)?

The passé composé is used because the team finishing earlier is a specific, completed event that happened as a direct consequence of his action. If you used the imparfait (finissait), it would imply a habitual consequence, meaning 'so that the team used to finish earlier'.