X0306 4 2020-03-09 1 0001561550 Datadog, Inc. DDOG 0001658115 OpenView Management, LLC 303 CONGRESS STREET, 7TH FLOOR BOSTON MA 02210 0 0 1 0 0001658112 OpenView General Partner III, L.P. 303 CONGRESS STREET, 7TH FLOOR BOSTON MA 02210 0 0 1 0 0001543059 OpenView Affiliates Fund III, L.P. 303 CONGRESS STREET, 7TH FLOOR BOSTON MA 02210 0 0 1 0 0001537612 OpenView Venture Partners III, L.P. 303 CONGRESS STREET, 7TH FLOOR BOSTON MA 02210 0 0 1 0 Class A Common Stock 2020-03-09 4 C 0 32646624 0.00 A 32646624 D Class A Common Stock 2020-03-09 4 C 0 1275677 0.00 A 1275677 D Class A Common Stock 2020-03-09 4 J 0 32531137 0.00 D 115487 D Class A Common Stock 2020-03-09 4 J 0 1271164 0.00 D 4513 D Class B Common Stock 2020-03-09 4 C 0 32646624 0.00 D Class A Common Stock 32646624 0 D Class B Common Stock 2020-03-09 4 C 0 1275677 0.00 D Class A Common Stock 1275677 0 D Each share of Class B Common Stock is convertible at any time at the option of the Reporting Person into one share of Class A Common Stock and has no expiration date. Each share of Class B Common Stock will convert automatically into one share of Class A Common Stock upon the earlier of: (i) any transfer, whether or not for value, except for certain "Permitted Transfers" as defined in the Issuer's amended and restated certificate of incorporation, and (ii) the tenth anniversary of the Issuer's initial public offering of its Class A Common Stock. The securities are held by OpenView Venture Partners III, L.P. ("OVP III LP"). OpenView Management, LLC ("OVM LLC") is the general partner of OpenView General Partner III, L.P. ("OGP III LP"), which is the general partner of OVP III LP. Each of OVM LLC and OGP III LP disclaims beneficial ownership of all the shares held by OVP III LP except to the extent, if any, of its pecuniary interest therein and this report shall not be deemed an admission that it is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose. The securities are held by OpenView Affiliates Fund III, L.P. ("OAF III LP"). OGP III LP is the general partner of OAF III LP. Each of OVM LLC and OGP III LP disclaims beneficial ownership of all the shares held by OAF III LP except to the extent, if any, of its pecuniary interest therein and this report shall not be deemed an admission that it is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose. On March 9, 2020 OVP III LP and OAF III LP distributed in-kind, without consideration shares of Class A Common Stock of the issuer to its partners, including their general partner, OGP III LP, which received 11,954,785 shares. OGP III LP in turn distributed in-kind, without consideration, 11,954,785 shares of Class A Common Stock of the issuer to its limited partners. The aforementioned distributions were made in accordance with the exemptions afforded by Rule 16a-13 and Rule 16a-9 of the Securities Exchange Act of 1934, as amended. /s/ Rufus King, Chief Legal Officer of OpenView Management, LLC 2020-03-11 /s/ Rufus King, Chief Legal Officer of OpenView Management, LLC, the general partner of OpenView General Partner III, L.P 2020-03-11 /s/ Rufus King, Chief Legal Officer of OpenView Management, LLC, the general partner of OpenView General Partner III, L.P., the general partner of OpenView Affiliates Fund III, L.P. 2020-03-11 /s/ Rufus King, Chief Legal Officer of OpenView Management, LLC, the general partner of OpenView General Partner III, L.P., the general partner of OpenView Venture Partners III, L.P. 2020-03-11