Fastly Inc

To the Stockholders and the Board of Directors of Fastly, Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Fastly, Inc. and subsidiaries (the“Company”) as of December 31, 2024 and 2023, the related consolidated statements of operations, comprehensive loss, stockholders’ equity, and cash flows, for each of the three years in the period ended December 31, 2024, and the related notes (collectively referred to as the“financial statements”). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2024 and 2023, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2024, in conformity with accounting principles generally accepted in the United States of America.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company’s internal control over financial reporting as of December 31, 2024, based on criteria established in Internal Control — Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated February 25, 2025, expressed an adverse opinion on the Company’s internal control over financial reporting because of a material weakness.

Basis for Opinion

These financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current-period audit of the financial statements that was communicated or required to be communicated to the audit committee and that (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Revenue – Refer to Notes 2 and 3 to the financial statements

Critical Audit Matter Description

Revenue is recognized upon transfer of control of promised products or services to customers in an amount that reflects the consideration the Company expects to receive in exchange for those products or services. The processing and recording of certain revenue requires a manual process, and therefore the Company uses a complex set of procedures to generate complete and accurate data to record its revenue transactions.

We identified manually processed revenue as a critical audit matteras the manually processed revenue requires a complex set of manual procedures to generate complete and accurate data to process and record revenue. This required an increased extent of effort to audit these manually processed revenue transactions.

How the Critical Audit Matter Was Addressed in the Audit

Our audit procedures related to manually processed revenue included the following, among others:

•We tested the effectiveness of controls over the recognition of manually processed revenue.

•We obtained an understanding of the nature of the manually processed revenue through inquiry with the Company personnel responsible for the invoice, as well as review of the contract with the customer.

•For a sample of manually processed revenue transactions, we recalculated the manually processed revenue by comparing key attributes utilized in our recalculation to source information and documents, including usage, bandwidth, and other services provided. We compared our recalculation of manually processed revenue transactions to the Company’s recorded revenue and evaluated any differences.

/s/Deloitte & Touche LLP

San Francisco, California

February 25, 2025

We have served as the Company’s auditor since 2015.