144 0001783984 XXXXXXXX LIVE 0001561550 Datadog, Inc. 001-39051 620 8th Avenue 45th Floor New York NY 10018 866-329-4466 Alexis Le-Quoc Officer Director Class A Common Stock Morgan Stanley Smith Barney LLC Executive Services

200 W Civic Center Dr - 4th Floor Sandy UT 84070

13868 1895478.24 323270704 09/02/2025 NASDAQ Class A Common Stock 09/01/2025 Restricted Stock Units and Performance Stock Units vesting Issuer N 13868 09/01/2025 Compensation N Alexis Le-Quoc

620 8th Avenue, 45th floor New York NY 10018

Class A Common Stock 08/05/2025 41468 5576002.91 Alexis Le-Quoc

620 8th Avenue, 45th floor New York NY 10018

Class A Common Stock 07/14/2025 41468 5775376.91 Alexis Le-Quoc

620 8th Avenue, 45th floor New York NY 10018

Class A Common Stock 06/04/2025 127105 15247350.6 Alexis Le-Quoc

620 8th Avenue, 45th floor New York NY 10018

Class A Common Stock 06/02/2025 13766 1608433.21 Securities to be sold were registered on Form S-8 09/02/2025 /s/ Alexis Le-Quoc