Exhibit 3.1

AMENDED AND RESTATED

CERTIFICATE OF INCORPORATION

OF

ALTAIR ENGINEERING INC.

ARTICLE I

The name of the Corporation is Altair Engineering Inc. (the “Corporation”).

ARTICLE II

The address of the Corporation’s registered office in the State of Delaware is 1209 Orange Street, Wilmington, County of New Castle, Delaware, 19801. The name of its registered agent at such address is The Corporation Trust Company.

ARTICLE III

The nature of the business or purposes to be conducted or promoted is to engage in any lawful act or activity for which corporations may be organized under the General Corporation Law of the State of Delaware (the “DGCL”), as it now exists or may hereafter be amended and supplemented.

ARTICLE IV

The total number of shares of stock which the Corporation has authority to issue is one thousand (1,000) shares of Common Stock, par value one cent ($0.01) per share.

ARTICLE V

The Corporation is to have perpetual existence.

ARTICLE VI

In furtherance and not in limitation of the powers conferred by statute, the board of directors of the Corporation (the “Board”) is expressly authorized to make, alter or repeal the Bylaws of the Corporation (the “Bylaws”), without any action on the part of the stockholders, but the stockholders may make additional Bylaws and may alter, amend or repeal any Bylaw whether adopted by them or otherwise. The Corporation may in its Bylaws confer powers upon its Board in addition to the foregoing and in addition to the powers and authorities expressly conferred upon the Board by applicable law.

ARTICLE VII

Meetings of stockholders may be held within or without the State of Delaware, as the Bylaws may provide. The books of the Corporation may be kept outside the State of Delaware at such place or places as may be designated from time to time by the Board or in the Bylaws. Election of directors need not be by written ballot unless the Bylaws so provide.

ARTICLE VIII

To the fullest extent permitted by the DGCL, as it presently exists or may hereafter be amended from time to time, a director of the Corporation shall not be personally liable to the Corporation or its stockholders for monetary damages for breach of fiduciary duty as a director or otherwise. If the DGCL is amended to authorize corporate action further eliminating or limiting the personal liability of directors, then the liability of a director of the Corporation shall be eliminated or limited to the fullest extent permitted by the DGCL, as so amended.

Neither any amendment nor repeal of this Article VIII, nor the adoption of any provision of this Amended and Restated Certificate of Incorporation inconsistent with this Article VIII, shall eliminate or reduce the effect of this Article VIII in respect of any matter occurring, or any cause of action, suit or proceeding accruing or arising or that, but for this Article VIII, would accrue or arise, prior to such amendment, repeal or adoption of an inconsistent provision.

ARTICLE IX

Subject to any provisions in the Bylaws related to indemnification of directors, officers or agents of the Corporation, the Corporation shall indemnify, to the fullest extent permitted by applicable law, any director, officer or agent of the Corporation who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (a “Proceeding”) by reason of the fact that he or she is or was a director, officer, employee or agent of the Corporation or is or was serving at the request of the Corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise, including service with respect to employee benefit plans, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by such person in connection with any such Proceeding; provided, however, that the Corporation be required to indemnify a person in connection with a Proceeding (or part thereof) initiated by such person only if such Proceeding (or part thereof) was authorized by the Board.

The Corporation shall have the power to indemnify, to the extent permitted by the DGCL, as it presently exists or may hereafter be amended from time to time, any employee or agent of the Corporation who was or is a party or is threatened to be made a party to any Proceeding by reason of the fact that he or she is or was a director, officer, employee or agent of the Corporation or is or was serving at the request of the Corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise, including service with respect to employee benefit plans, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by such person in connection with any such Proceeding.

A right to indemnification or to advancement of expenses arising under a provision of this Amended and Restated Certificate of Incorporation or the Bylaws shall not be eliminated or impaired by an amendment to this Amended and Restated Certificate of Incorporation or the Bylaws after the occurrence of the act or omission that is the subject of the civil, criminal, administrative or investigative action, suit or proceeding for which indemnification or advancement of expenses is sought, unless the provision in effect at the time of such act or omission explicitly authorizes such elimination or impairment after such action or omission has occurred.

ARTICLE X

The Corporation expressly elects not to be governed by §203 of the DGCL.

ARTICLE XI

The Corporation reserves the right to amend, alter, change or repeal any provision contained in this Amended and Restated Certificate of Incorporation in the manner now or hereafter prescribed herein and by the laws of the State of Delaware, and all rights conferred upon stockholders herein are granted subject to this reservation.

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