Having dislodged banks and consultancies as graduates’ dream workplaces, big tech attracted hundreds of thousands of talentsed people in the past years.

To quantify the number of years you could say "the recent past", " the past few years" or " many years in the past"

As people from different backgrounds, or in different stages of their careers flooded into the tech industry, they are alsowere plagued by different concerns.

You have started in the past tense so need to continue in the past tense

Some awere not clear about the career path from a college graduate to a senior engineer/manager position in tech companies.

Some may have wondered about the difference between big tech and start-ups.

Many wanted to know more about typical pitfalls during their early career.

Both XXX and XXX are currently managers at big tech firms, and they willould be happy to share about their career paths and answer audiences’ questions during the talk.

Having dislodged banks and consultancies as graduates’ dream workplaces, big tech has attracted hundreds of thousands of talents in the past years.

Many want to know more about typical pitfalls durearly ing their early career.

I would phrase this sentence like this.

For those coming from a non–tech background, it is also interesting to know how they can set their steps into this thriving area.

Both XXX and XXX are currently managers at big tech firms, and they will be happy to share about their career paths and answer the audience's’ questions during the talk.

Audiences' questions = the questions of more than one audience
Audience's questions = the qustions of one audience