(Unaudited) | ||||||||||||||||
Three Months Ended
September 30, |
Nine Months Ended
September 30, | |||||||||||||||
2021 | 2020 | 2021 | 2020 | |||||||||||||
Cost of revenue – maintenance and other services | $ | 1,411 | $ | 684 | $ | 3,791 | $ | 1,602 | ||||||||
Research and development | 3,894 | 2,428 | 11,223 | 5,686 | ||||||||||||
Sales and marketing | 3,673 | 1,949 | 10,800 | 3,949 | ||||||||||||
General and administrative | 1,955 | 1,173 | 5,415 | 2,702 | ||||||||||||
Total stock-based compensation expense | $ | 10,933 | $ | 6,234 | $ | 31,229 | $ | 13,939 | ||||||||
ALTAIR ENGINEERING INC. AND SUBSIDIARIES