Is this sexist? (spoiler: YES)

So my workplace is working on a new software project. Whenever the designers talk about a potential user who is a customer service representative, they use the pronoun "she". Whenever they talk about a potential user who is a technician of some sort, they use the pronoun "he". I scribbled the word "they" on my notepad as a reminder to myself to make sure not to fall into that habit.