X0306 4 2020-07-14 0 0001561550 Datadog, Inc. DDOG 0001784030 Callahan Michael James C/O DATADOG, INC. 620 8TH AVENUE, 45TH FLOOR NEW YORK NY 10018 1 0 0 0 Class A Common Stock 2020-07-14 4 C 0 250000 0.00 A 255959 D Class A Common Stock 20000 I By GRAT 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 earliest 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, (ii) the death of the Reporting Person in the case of shares held directly or in a trustee capacity, and (iii) the tenth anniversary of the Issuer's initial public offering of its Class A Common Stock. Shares are held directly by The Michael Callahan Grantor Retained Annuity Trust, of which Reporting Person is Trustee. Michael Callahan, by /s/ Ron A. Metzger, Attorney-in-Fact 2020-07-16