September 24, 2024 Matthew Brown Chief Financial Officer Altair Engineering Inc. 1820 East Big Beaver Road Troy, MI 48083 Re: Altair Engineering Inc. Form 10-K for the year ended December 31, 2023 File No. 001-38263 Dear Matthew Brown: We have completed our review of your filing. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Sincerely, Division of Corporation Finance Office of Technology cc: Brian Gayle