Mayor Michelle Wu has appointed Kairos Shen as Boston’s new Chief of Planning.

Shen will lead the Planning Department, which was established by Wu in July.

“I’m thrilled to welcome Kairos into leadership of Boston’s Planning Department and all the critical functions shaping the built environment for affordability, equity, and resilience,” said Wu. “As a longtime friend and advisor, Kairos brings an unparalleled knowledge and expertise of this work and our communities. ”

The new department was created by a mayoral ordinance that was approved by the City Council in late March, but the changes — moving staff and functions along with some land and money from the Boston Planning and Development Agency — did not take effect until the start of fiscal year 2025.

Most of the BPDA’s staff have transitioned into jobs with the City of Boston and are considered to be employees of the new Planning Department.

Shen said he is “excited to return to City Hall with a fresh perspective after a decade of teaching, research, and mentoring the next generation of urban planners and designers” at MIT.

He will maintain an affiliation with MIT while working for the city, the mayor’s office added.

Shen worked in City Hall in a number of different roles in planning and design over the course of two decades under Mayor Thomas Menino and Mayor Martin Walsh.