Exhibit A

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, each of the undersigned hereby agrees to the joint filing, along with all other such undersigned, on behalf of the Reporting Persons (as defined in the joint filing), of an amended statement on Schedule 13G (including such other amendments thereto) with respect to the common stock of Byline Bancorp, Inc., and that this agreement be included as an exhibit to such joint filing. This agreement may be executed in any number of counterparts, all of which taken together shall constitute one and the same instrument. The undersigned acknowledge that each shall be responsible for the timely filing of any further amendments, and for the completeness and accuracy of the information concerning him or it contained herein and therein, but shall not be responsible for the completeness and accuracy of the information concerning the others.

IN WITNESS WHEREOF, each of the undersigned hereby executes this agreement as of this 14^th day of August, 2026.

MBG Investors I, L.P.

By: /s/ Antonio del Valle Perochena

Name: Antonio del Valle Perochena Title: General Partner

          /s/ Antonio del Valle Perochena

Name: Antonio del Valle Perochena