Bulletproof founder and CEO Anthony Woodward said "Neil's addition to our team is just one of the many steps we're taking" to continue to increase revenue and attract big-name customers.
Waller was previously head of install base sales at Rackspace after starting as a senior account manager.
He will report directly to another former Rackspace employee, Bulletproof's director of sales and marketing Mark Randall.
"Customers want real people to talk to when they need assistance or advice — someone who is easily accessible and available, and a lot of companies fail to provide this service," said Waller.
"This is where Bulletproof stands out. The team and I will work together to identify areas where we can provide unparalleled and unmatched customer service."