POWER OF ATTORNEY

        KNOW ALL BY THESE PRESENTS, that the undersigned hereby makes,
constitutes and appoints Christopher H. Turner and Tara O'Neill, acting singly
and with full power of substitution or revocation, the undersigned's true and
lawful attorneys-in-fact, with full power and authority as hereinafter described
on behalf of and in the name, place and stead of the undersigned to:

        (i)    execute for and on behalf of the undersigned, in the
               undersigned's capacity as a director, director nominee, officer
               or beneficial owner of shares of common stock of Warburg Pincus
               Capital Corporation I-B, a Cayman Islands exempted company (the
               "Company"), any Schedule 13D or Schedule 13G, and any amendments,
               supplements or exhibits thereto (including any joint filing
               agreements) required to be filed by the undersigned under Section
               13 of the Securities Exchange Act of 1934, as amended, and the
               rules promulgated thereunder (the "Exchange Act"), and any Forms
               3, 4, and 5 and any amendments, supplements or exhibits thereto
               required to be filed by the undersigned under Section 16(a) of
               the Exchange Act;

        (ii)   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 schedules or forms and timely file such forms
               with the United States Securities and Exchange Commission and any
               applicable stock exchange; and

        (iii)  take any other action of any type whatsoever in connection with
               the foregoing which, in the opinion of such attorneys-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 attorneys-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
               attorneys-in-fact may approve in such attorneys-in-fact's
               discretion.

        The undersigned hereby grants to such attorneys-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 attorneys-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. The undersigned acknowledges
that the foregoing attorneys-in-fact, in serving in such capacity at the request
of the undersigned, are not assuming, nor is the Company assuming, any of the
undersigned's responsibilities to comply with, or any liability for the failure
to comply with, Section 13 and/or Section 16 of the Exchange Act

        This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file reports or schedules under Section 13
or Section 16 of the Exchange Act with respect to the Company, 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 26th day of August, 2021.

                                        By:    /s/ Anne Walker
                                               ---------------------------------
                                        Name:  Anne Walker