So-Young International (SY) SC 13G/A So-Young International / ATCG ownership change

EXHIBIT A

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k) promulgated under the Securities Exchange Act of 1934, as amended, the undersigned hereby agree to the joint filing with all other Reporting Persons (as such term is defined in the Schedule 13G referred to below) on behalf of each of them of a statement on Schedule 13G (including amendments thereto) with respect to the ordinary shares, par value of $0.0005 per share, of So-Young International Inc., a Cayman Islands company, and that this Agreement may 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.

IN WITNESS WHEREOF, the undersigned hereby execute this Agreement as of January 28, 2023.

Hui Shao
By:	/s/ Hui Shao
ATCG Holdings Limited
By:	/s/ Hui Shao
Name: Hui Shao
Title: Director