Software Integration team are responsible for build, test and install E4S using Spack at the facility. The SI team works closely with E4S team to help build E4S stack at all facility. Currently, we are building E4S for the following systems: Cori (NERSC), Ascent (OLCF), Iris & Yarrow (ALCF). We makes use of gitlab and spack pipeline (spack ci) in order to build E4S stack and provide a buildcache so that users or other facility can leverage buildcache to satisfy build dependency to accelerate build time.