SEC Form 3 
FORM 3	UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940 	  
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1. Name and Address of Reporting Person*
De Madre Armelle	

(Last)	(First)	(Middle)	
C/O DATADOG, INC.	
620 8TH AVENUE, 45TH FLOOR	

(Street) 
NEW YORK	NY	10018	

(City)	(State)	(Zip)	
	2. Date of Event Requiring Statement (Month/Day/Year)
09/18/2019 	3. Issuer Name and Ticker or Trading Symbol 
Datadog, Inc. [ DDOG ] 		
		4. Relationship of Reporting Person(s) to Issuer 
(Check all applicable) 
	Director		10% Owner	
X	Officer (give title below)		Other (specify below)	
Chief People Officer	
	5. If Amendment, Date of Original Filed (Month/Day/Year)				
			6. Individual or Joint/Group Filing (Check Applicable Line) 
X	Form filed by One Reporting Person	
	Form filed by More than One Reporting Person	
	
Table I - Non-Derivative Securities Beneficially Owned	
1. Title of Security (Instr. 4) 	2. Amount of Securities Beneficially Owned (Instr. 4) 	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 	4. Nature of Indirect Beneficial Ownership (Instr. 5) 	
Table II - Derivative Securities Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities) 	
1. Title of Derivative Security (Instr. 4) 	2. Date Exercisable and Expiration Date (Month/Day/Year)	3. Title and Amount of Securities Underlying Derivative Security (Instr. 4) 	4. Conversion or Exercise Price of Derivative Security 	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 	6. Nature of Indirect Beneficial Ownership (Instr. 5) 	
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares				
Stock Option (Right to Buy)	(1) 	06/28/2029	Common Stock	270,000(2) 	7.9567	D		
Explanation of Responses:	
1. Option vests as to 25% on June 20, 2020 and in equal monthly installments thereafter over three years.	
2. Each share of Common Stock shall be reclassified into one share of Class B Common Stock immediately prior to the completion of the Issuer's initial public offering of Class A Common Stock.	
Remarks:	
	
	Armelle De Madre, by /s/ Ron A. Metzger, Attorney-in-Fact	09/18/2019	
	** Signature of Reporting Person	Date	
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.	
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).	
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).	
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.	
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.	
POWER OF ATTORNEY

        Know all by these presents, that the undersigned hereby constitutes and
appoints Kerry Acocella of Datadog, Inc. and Jodie M. Bourdet, Alison Haggerty,
Nicole Brookshire and Ron A. Metzger of Cooley LLP, or any of them signing
singly, with full power of substitution, the undersigned's true and lawful
attorney in fact to:
(1)             prepare, execute in the undersigned's name and on the undersigned's behalf,
and submit to the U.S. Securities and Exchange Commission (the "SEC") a Form ID
Application to Obtain EDGAR Access Codes and any other forms necessary to
generate EDGAR codes on my behalf enabling the undersigned to make electronic
filings with the SEC of reports required by Section 16(a) of the Securities
Exchange Act of 1934 or any rule or regulation of the SEC;
(2)     execute for and on behalf of the undersigned, in the undersigned's capacity
as a director, officer and/or a 10% stockholder of Dynavax Technologies, Inc.
(the "Company"), Forms 3, 4, and 5 in accordance with Section 16(a) of the
Securities Exchange Act of 1934 and the rules thereunder;
(3)             do and perform any and all acts for and on behalf of the undersigned which
may be necessary or desirable to complete and execute any such Form 3, 4, or 5,
complete and execute any amendment or amendments thereto, and timely file such
form with the SEC and any stock exchange or similar authority; and
(4)     take any other action of any type whatsoever in connection with the
foregoing which, in the opinion of such attorney in fact, may be of benefit to,
in the best interest of, or legally required by, the undersigned, it being
understood that the documents executed by such attorney in fact on behalf of the
undersigned pursuant to this Power of Attorney shall be in such form and shall
contain such terms and conditions as such attorney in fact may approve in such
attorney in fact's discretion.
        The undersigned hereby grants to such attorney in fact full power and authority
to do and perform any and every act and thing whatsoever requisite, necessary,
or proper to be done in the exercise of any of the rights and powers herein
granted, as fully to all intents and purposes as the undersigned might or could
do if personally present, with full power of substitution or revocation, hereby
ratifying and confirming all that such attorney in fact, or such attorney in
fact's substitute or substitutes, shall lawfully do or cause to be done by
virtue of this power of attorney and the rights and powers herein granted.
        This Power of Attorney shall remain in full force and effect until either the
undersigned is no longer required to file Forms 3, 4, and 5 with respect to the
undersigned's holdings of and transactions in securities issued by the Company
or unless earlier revoked by the undersigned in a signed writing delivered to
the foregoing attorneys in fact.
IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of this 11th day of September, 2019.

        /s/ Armelle de Madre