diff --git a/lib/spack/spack/cmd/ci.py b/lib/spack/spack/cmd/ci.py
index e89d483ed27..fb1a438ba8c 100644
--- a/lib/spack/spack/cmd/ci.py
+++ b/lib/spack/spack/cmd/ci.py
@@ -16,6 +16,7 @@
 import spack.ci as spack_ci
 import spack.cmd
 import spack.cmd.buildcache as buildcache
+import spack.cmd.common.arguments
 import spack.config as cfg
 import spack.environment as ev
 import spack.hash_types as ht
@@ -119,6 +120,9 @@ def setup_parser(subparser):
     )
     generate.set_defaults(func=ci_generate)
 
+    spack.cmd.common.arguments.add_concretizer_args(generate)
+    spack.cmd.common.arguments.add_common_arguments(generate, ["jobs"])
+
     # Rebuild the buildcache index associated with the mirror in the
     # active, gitlab-enabled environment.
     index = subparsers.add_parser(
@@ -148,6 +152,7 @@ def setup_parser(subparser):
         help="stop stand-alone tests after the first failure",
     )
     rebuild.set_defaults(func=ci_rebuild)
+    spack.cmd.common.arguments.add_common_arguments(rebuild, ["jobs"])
 
     # Facilitate reproduction of a failed CI build job
     reproduce = subparsers.add_parser(
@@ -411,6 +416,9 @@ def ci_rebuild(args):
     if not verify_binaries:
         install_args.append("--no-check-signature")
 
+    if args.jobs:
+        install_args.append(f"-j{args.jobs}")
+
     slash_hash = spack_ci.common.win_quote("/" + job_spec.dag_hash())
 
     # Arguments when installing the root from sources
diff --git a/share/spack/gitlab/cloud_pipelines/.gitlab-ci.yml b/share/spack/gitlab/cloud_pipelines/.gitlab-ci.yml
index ce29513db41..4a0351e4501 100644
--- a/share/spack/gitlab/cloud_pipelines/.gitlab-ci.yml
+++ b/share/spack/gitlab/cloud_pipelines/.gitlab-ci.yml
@@ -145,7 +145,7 @@ default:
       --config-scope "${SPACK_CI_CONFIG_ROOT}"
       --config-scope "${SPACK_CI_CONFIG_ROOT}/${SPACK_TARGET_PLATFORM}"
       --config-scope "${SPACK_CI_CONFIG_ROOT}/${SPACK_TARGET_PLATFORM}/${SPACK_TARGET_ARCH}"
-      ci generate --check-index-only
+      ci generate --check-index-only -j ${SPACK_CONCRETIZE_JOBS}
       --artifacts-root "${CI_PROJECT_DIR}/jobs_scratch_dir"
       --output-file "${CI_PROJECT_DIR}/jobs_scratch_dir/cloud-ci-pipeline.yml"
   artifacts:
@@ -155,7 +155,8 @@ default:
       - "${CI_PROJECT_DIR}/tmp/_user_cache/cache/providers"
       - "${CI_PROJECT_DIR}/tmp/_user_cache/cache/tags"
   variables:
-    KUBERNETES_CPU_REQUEST: 4000m
+    SPACK_CONCRETIZE_JOBS: 8
+    KUBERNETES_CPU_REQUEST: 8000m
     KUBERNETES_MEMORY_REQUEST: 16G
     # avoid moving targets like branches and tags
     SPACK_CONCRETIZER_REQUIRE_CHECKSUM: 1
@@ -408,6 +409,8 @@ e4s-oneapi-build:
   extends: [".linux_power"]
   variables:
     SPACK_CI_STACK_NAME: e4s-power
+    # Override concretization pool for metal runners
+    SPACK_CONCRETIZE_JOBS: 16
 
 e4s-power-generate:
   extends: [ ".e4s-power", ".generate-x86_64", ".e4s-power-generate-tags-and-image"]
@@ -860,6 +863,10 @@ aws-pcluster-build-neoverse_v1:
 # Cray definitions
 .generate-cray:
   extends: [ ".generate-common", ".base-job" ]
+  variables:
+    # Override concretization pool for metal runners
+    SPACK_CONCRETIZE_JOBS: 16
+
   before_script:
     - echo $PATH
     - module avail
@@ -936,6 +943,10 @@ e4s-cray-sles-build:
   extends: [".win64-msvc2019"]
   variables:
     SPACK_CI_STACK_NAME: windows-vis
+    # TODO: windows runners are currently m5.2xlarge with a max 8 vCPU and 32GiB MEM
+    # setting request to half of the available allocation to allow room for overhead.
+    KUBERNETES_CPU_REQUEST: 4000m
+    KUBERNETES_MEMORY_REQUEST: 16G
 
 windows-vis-generate:
   extends: [ ".generate-win64", ".windows-vis" ]
diff --git a/share/spack/gitlab/cloud_pipelines/configs/ci.yaml b/share/spack/gitlab/cloud_pipelines/configs/ci.yaml
index 10eb7459a71..b3e151e5bd9 100644
--- a/share/spack/gitlab/cloud_pipelines/configs/ci.yaml
+++ b/share/spack/gitlab/cloud_pipelines/configs/ci.yaml
@@ -15,7 +15,6 @@ ci:
       - - touch ${SPACK_USER_CACHE_PATH}/cache/*/*  # bump mtime of cache so it is not invalidated
       - - spack env activate --without-view ${SPACK_CONCRETE_ENV_DIR}
         - spack compiler list
-        - if [ -n "$SPACK_BUILD_JOBS" ]; then spack config add "config:build_jobs:$SPACK_BUILD_JOBS"; fi
       - - mkdir -p ${SPACK_ARTIFACTS_ROOT}/user_data
         # AWS runners mount E4S public key (verification), UO runners mount public/private (signing/verification)
       - - k=$CI_GPG_KEY_ROOT/e4s.gpg; [[ -r $k ]] && spack gpg trust $k
@@ -24,7 +23,7 @@ ci:
         - k=$CI_GPG_KEY_ROOT/spack_public_key.gpg; [[ -r $k ]] && spack gpg trust $k
       script::
       - - spack config blame mirrors
-        - spack --color=always --backtrace ci rebuild --tests > >(tee ${SPACK_ARTIFACTS_ROOT}/user_data/pipeline_out.txt) 2> >(tee ${SPACK_ARTIFACTS_ROOT}/user_data/pipeline_err.txt >&2)
+        - spack --color=always --backtrace ci rebuild -j ${SPACK_BUILD_JOBS} --tests > >(tee ${SPACK_ARTIFACTS_ROOT}/user_data/pipeline_out.txt) 2> >(tee ${SPACK_ARTIFACTS_ROOT}/user_data/pipeline_err.txt >&2)
       after_script:
       - - cat /proc/loadavg || true
         - cat /proc/meminfo | grep 'MemTotal\|MemFree' || true
@@ -34,6 +33,9 @@ ci:
           ${SPACK_ARTIFACTS_ROOT}/user_data/install_times.json || true
       variables:
         CI_JOB_SIZE: "default"
+        SPACK_BUILD_JOBS: "4"
+        KUBERNETES_CPU_REQUEST: "4000m"
+        KUBERNETES_MEMORY_REQUEST: "16G"
         CI_GPG_KEY_ROOT: /mnt/key
         # SPACK_VERBOSE_SCRIPT: "1"
       id_tokens:
diff --git a/share/spack/spack-completion.bash b/share/spack/spack-completion.bash
index 3e5449b5e80..a9a70c6e6b3 100644
--- a/share/spack/spack-completion.bash
+++ b/share/spack/spack-completion.bash
@@ -693,7 +693,7 @@ _spack_ci() {
 }
 
 _spack_ci_generate() {
-    SPACK_COMPREPLY="-h --help --output-file --prune-dag --no-prune-dag --prune-externals --no-prune-externals --check-index-only --artifacts-root"
+    SPACK_COMPREPLY="-h --help --output-file --prune-dag --no-prune-dag --prune-externals --no-prune-externals --check-index-only --artifacts-root -U --fresh --reuse --fresh-roots --reuse-deps --deprecated -j --jobs"
 }
 
 _spack_ci_rebuild_index() {
@@ -701,7 +701,7 @@ _spack_ci_rebuild_index() {
 }
 
 _spack_ci_rebuild() {
-    SPACK_COMPREPLY="-h --help -t --tests --fail-fast"
+    SPACK_COMPREPLY="-h --help -t --tests --fail-fast -j --jobs"
 }
 
 _spack_ci_reproduce_build() {
diff --git a/share/spack/spack-completion.fish b/share/spack/spack-completion.fish
index 87406306859..21449013e89 100644
--- a/share/spack/spack-completion.fish
+++ b/share/spack/spack-completion.fish
@@ -955,7 +955,7 @@ complete -c spack -n '__fish_spack_using_command ci' -s h -l help -f -a help
 complete -c spack -n '__fish_spack_using_command ci' -s h -l help -d 'show this help message and exit'
 
 # spack ci generate
-set -g __fish_spack_optspecs_spack_ci_generate h/help output-file= prune-dag no-prune-dag prune-externals no-prune-externals check-index-only artifacts-root=
+set -g __fish_spack_optspecs_spack_ci_generate h/help output-file= prune-dag no-prune-dag prune-externals no-prune-externals check-index-only artifacts-root= U/fresh reuse fresh-roots deprecated j/jobs=
 complete -c spack -n '__fish_spack_using_command ci generate' -s h -l help -f -a help
 complete -c spack -n '__fish_spack_using_command ci generate' -s h -l help -d 'show this help message and exit'
 complete -c spack -n '__fish_spack_using_command ci generate' -l output-file -r -f -a output_file
@@ -972,6 +972,16 @@ complete -c spack -n '__fish_spack_using_command ci generate' -l check-index-onl
 complete -c spack -n '__fish_spack_using_command ci generate' -l check-index-only -d 'only check spec state from buildcache indices'
 complete -c spack -n '__fish_spack_using_command ci generate' -l artifacts-root -r -f -a artifacts_root
 complete -c spack -n '__fish_spack_using_command ci generate' -l artifacts-root -r -d 'path to the root of the artifacts directory'
+complete -c spack -n '__fish_spack_using_command ci generate' -s U -l fresh -f -a concretizer_reuse
+complete -c spack -n '__fish_spack_using_command ci generate' -s U -l fresh -d 'do not reuse installed deps; build newest configuration'
+complete -c spack -n '__fish_spack_using_command ci generate' -l reuse -f -a concretizer_reuse
+complete -c spack -n '__fish_spack_using_command ci generate' -l reuse -d 'reuse installed packages/buildcaches when possible'
+complete -c spack -n '__fish_spack_using_command ci generate' -l fresh-roots -l reuse-deps -f -a concretizer_reuse
+complete -c spack -n '__fish_spack_using_command ci generate' -l fresh-roots -l reuse-deps -d 'concretize with fresh roots and reused dependencies'
+complete -c spack -n '__fish_spack_using_command ci generate' -l deprecated -f -a config_deprecated
+complete -c spack -n '__fish_spack_using_command ci generate' -l deprecated -d 'allow concretizer to select deprecated versions'
+complete -c spack -n '__fish_spack_using_command ci generate' -s j -l jobs -r -f -a jobs
+complete -c spack -n '__fish_spack_using_command ci generate' -s j -l jobs -r -d 'explicitly set number of parallel jobs'
 
 # spack ci rebuild-index
 set -g __fish_spack_optspecs_spack_ci_rebuild_index h/help
@@ -979,13 +989,15 @@ complete -c spack -n '__fish_spack_using_command ci rebuild-index' -s h -l help
 complete -c spack -n '__fish_spack_using_command ci rebuild-index' -s h -l help -d 'show this help message and exit'
 
 # spack ci rebuild
-set -g __fish_spack_optspecs_spack_ci_rebuild h/help t/tests fail-fast
+set -g __fish_spack_optspecs_spack_ci_rebuild h/help t/tests fail-fast j/jobs=
 complete -c spack -n '__fish_spack_using_command ci rebuild' -s h -l help -f -a help
 complete -c spack -n '__fish_spack_using_command ci rebuild' -s h -l help -d 'show this help message and exit'
 complete -c spack -n '__fish_spack_using_command ci rebuild' -s t -l tests -f -a tests
 complete -c spack -n '__fish_spack_using_command ci rebuild' -s t -l tests -d 'run stand-alone tests after the build'
 complete -c spack -n '__fish_spack_using_command ci rebuild' -l fail-fast -f -a fail_fast
 complete -c spack -n '__fish_spack_using_command ci rebuild' -l fail-fast -d 'stop stand-alone tests after the first failure'
+complete -c spack -n '__fish_spack_using_command ci rebuild' -s j -l jobs -r -f -a jobs
+complete -c spack -n '__fish_spack_using_command ci rebuild' -s j -l jobs -r -d 'explicitly set number of parallel jobs'
 
 # spack ci reproduce-build
 set -g __fish_spack_optspecs_spack_ci_reproduce_build h/help runtime= working-dir= s/autostart gpg-file= gpg-url=