His colleagues tell Bloomberg that Pichai tends to walk it out when he's deep in thought. It's not unusual for him to wander away in the middle of a meeting, only to return with the solution to whatever problem is being discussed.
Born in Chennai in the state of Tamil Nadu, India, in 1972, Sundar's full name is Pichai Sundararajan. Though he had a modest upbringing, he's now worth a reported $150 million.
His father, an electrical engineer, had to save for three years to buy the family a new scooter, but made sure Pichai and his brother had the best education the family could afford, at Padma Seshadri Bala Bhavan.
Pichai's father told Bloomberg he believes that talking to young Sundar about the challenges in his work as an electrical engineer led to his son's interest in technology.
Prior to joining Google, he did management consulting with McKinsey & Company.
Pichai has been with Google since 2004, when he joined to lead product management for Google Chrome and Chrome OS. He was involved with Google Drive and went on to oversee Gmail and Google Maps, as well.
In 2011, Pichai drew attention when he was considered to lead product and replace Jason Goldman at Twitter. He chose to stay with Google.
In 2013, Pichai took over Android founder Andy Rubin's portfolio to run mobile platforms. He was also entrusted with wooing more than a billion global users to the Android ecosystem.
According to Business Insider, Pichai was skilled at staying out of politics and drama at Google. When he reported to Marissa Mayer, he reportedly sat outside her office for hours, if necessary, to make sure his team had good performance reviews.
When he was almost lured away to Microsoft, Google reportedly negotiated desperately to retain Pichai for $50 million a year in stocks.
"Android One," Pichai's pet project designed to provide affordable smartphones in all households worldwide, launched in India in September 2014.
Though he was just appointed CEO of Google, Pichai has effectively been responsible for day-to-day operations at Google since October 2014.
Pichai had been Page's right-hand man for some time and is credited with trying to convince WhatsApp founder Jan Koum not to sell to Facebook. He also helped Page convince Nest's Tony Fadell to merge his company with the Google team, among other things.
Dieter Bohn at The Verge describes Pichai's office as "clean to the point of being spartan" and noted that this simplicity was reflected in his demeanor.
Now married to his love Anjali, whom he dated in India before she joined him in the United States, Pichai is the father of two.
Pichai is known for his soft-spoken, diplomatic nature. In 2013, he accompanied Larry Page and Google CBO Nikesh Arora to tour a Samsung factory in South Korea to help build Google's relationship with its partner.
Pichai has an unusual gift that seemed little more than a curiosity to him when he was a child, but has served him incredibly well in adulthood: he has insane numerical recall and can remember every number he's ever dialled.