EXHIBIT 99.1

JOINT FILING AGREEMENT

We, the undersigned, hereby express our agreement that the attached Schedule 13G (or any amendments thereto) relating to the Class A common stock of Rubrik, Inc. on behalf of each of us.

Dated: May 15, 2025

Lightspeed Venture Partners IX, L.P. By: Lightspeed General Partner IX, L.P. Its General Partner By: Lightspeed Ultimate General Partner IX, Ltd. Its General Partner By: /s/ Ravi Mhatre Name: Ravi Mhatre Title: Director Lightspeed General Partner IX, L.P. By: Lightspeed Ultimate General Partner IX, Ltd. Its General Partner By: /s/ Ravi Mhatre Name: Ravi Mhatre Title: Director Lightspeed Ultimate General Partner IX, Ltd. By: /s/ Ravi Mhatre Name: Ravi Mhatre Title: Director Lightspeed Venture Partners X, L.P. By: Lightspeed General Partner X, L.P. Its General Partner By: Lightspeed Ultimate General Partner X, Ltd. Its General Partner By: /s/ Ravi Mhatre Name: Ravi Mhatre Title: Director Lightspeed Affiliates X, L.P. By: Lightspeed General Partner X, L.P. Its General Partner By: Lightspeed Ultimate General Partner X, Ltd. Its General Partner By: /s/ Ravi Mhatre Name: Ravi Mhatre Title: Director

Lightspeed SPV I, LLC Lightspeed SPV I-B, LLC Lightspeed SPV I-C, LLC By: LS SPV Management, LLC Its General Partner By: /s/ Ravi Mhatre Name: Ravi Mhatre Title: Managing Member LS SPV Management, LLC By: /s/ Ravi Mhatre Name: Ravi Mhatre Title: Managing Member Lightspeed Venture Partners Select II, L.P. By: Lightspeed General Partner Select II, L.P. Its General Partner By: Lightspeed Ultimate General Partner Select II, Ltd. Its General Partner By: /s/ Ravi Mhatre Name: Ravi Mhatre Title: Director Lightspeed General Partner Select II, L.P. By: Lightspeed Ultimate General Partner Select II, Ltd. Its General Partner By: /s/ Ravi Mhatre Name: Ravi Mhatre Title: Director Lightspeed Ultimate General Partner Select II, Ltd. By: /s/ Ravi Mhatre Name: Ravi Mhatre Title: Director Lightspeed Management Company, L.L.C. By: /s/ Ravi Mhatre Name: Ravi Mhatre Title: Managing Member

Lightspeed General Partner X, L.P. By: Lightspeed Ultimate General Partner X, Ltd. Its General Partner By: /s/ Ravi Mhatre Name: Ravi Mhatre Title: Director Lightspeed Ultimate General Partner X, Ltd. By: /s/ Ravi Mhatre Name: Ravi Mhatre Title: Director

Barry Eggers /s/ Barry Eggers Ravi Mhatre /s/ Ravi Mhatre Peter Nieh /s/ Peter Nieh