Her second mentor appeared when she joined BT. She worked on the team of former BT Group CIO Al-Noor Ramji, a man she effusively describes as an "inspirational character". She witnessed Ramji transform BT - before he left last year to join financial services software firm Misys - and strongly believes that she learned her business transformation skills from him.
What these two mentors had in common was their accessibility, and their willingness to share their expertise, said Zarraga.
"They made themselves accessible to me. They took me to meetings, showed me how they operate on a day-to-day basis. It's good that people talk to you and share their experience with you," she said.
But Zarraga did not play a passive role either. To make the most of what she has learned from her mentors, she said she makes a real effort to understand the business.
"I fully understand the direction of the business and what they [the bosses] consider is important for the business, and what makes the business tick," she explained.
Moreover, she is proactive in sharing her experiences, and finds that being on the end of the mentoring process is just as rewarding.
Zarraga, who mentors both men and women, said: "For me, mentoring is 100% part of my job. I help people grow, and seeing them grow is a great satisfaction. I make sure I'm accessible to people in the same way so that people grow, and it is a very rewarding part of my job."