diff --git a/data/common/common.yaml b/data/common/common.yaml
--- a/data/common/common.yaml
+++ b/data/common/common.yaml
@@ -1965,6 +1965,8 @@
   extraction_dir: /tmp/swh-deposit/archive/
   swh_authority_url: "%{hiera('swh::deploy::deposit::url')}/"
 
+swh::deploy::worker::loader::max_content_size: 104857600
+
 swh::deploy::worker::loader_deposit::config_file: "%{hiera('swh::conf_directory')}/loader_deposit.yml"
 swh::deploy::worker::loader_deposit::concurrency: 1
 swh::deploy::worker::loader_deposit::private_tmp: true
@@ -1972,7 +1974,7 @@
 # deposit_basic_auth_swhworker_{username|password} in private_data
 swh::deploy::worker::loader_deposit::config:
   storage: "%{alias('swh::deploy::worker::storage::pipeline')}"
-  max_content_size: 104857600
+  max_content_size: "%{alias('swh::deploy::worker::loader::max_content_size')}"
   celery:
     task_broker: "%{alias('swh::deploy::worker::task_broker')}"
     task_queues:
@@ -2341,7 +2343,7 @@
 swh::deploy::worker::loader_git::loglevel: info
 swh::deploy::worker::loader_git::config:
   storage: "%{alias('swh::deploy::worker::storage::pipeline')}"
-  max_content_size: 104857600
+  max_content_size: "%{alias('swh::deploy::worker::loader::max_content_size')}"
   temp_file_cutoff: "%{alias('swh::deploy::worker::loader_git::temp_file_cutoff')}"
   celery:
     task_broker: "%{alias('swh::deploy::worker::task_broker')}"
@@ -2358,7 +2360,7 @@
 swh::deploy::worker::loader_high_priority::loglevel: info
 swh::deploy::worker::loader_high_priority::config:
   storage: "%{alias('swh::deploy::worker::storage::pipeline')}"
-  max_content_size: 104857600
+  max_content_size: "%{alias('swh::deploy::worker::loader::max_content_size')}"
   celery:
     task_broker: "%{alias('swh::deploy::worker::task_broker')}"
     task_queues:
@@ -2372,6 +2374,20 @@
       - save_code_now:swh.loader.svn.tasks.MountAndLoadSvnRepository
       - save_code_now:swh.loader.svn.tasks.DumpMountAndLoadSvnRepository
 
+# One shot worker deactivated by default (e.g. first time ingestion on forge with
+# restrictive loading ingestion parallelism policies)
+swh::deploy::worker::loader_oneshot::config_file: "%{hiera('swh::conf_directory')}/loader_oneshot.yml"
+swh::deploy::worker::loader_oneshot::concurrency: 1
+swh::deploy::worker::loader_oneshot::max_tasks_per_child: 100
+swh::deploy::worker::loader_oneshot::loglevel: info
+swh::deploy::worker::loader_oneshot::task_queues: []
+swh::deploy::worker::loader_oneshot::config:
+  storage: "%{alias('swh::deploy::worker::storage::pipeline')}"
+  max_content_size: "%{alias('swh::deploy::worker::loader::max_content_size')}"
+  celery:
+    task_broker: "%{alias('swh::deploy::worker::task_broker')}"
+    task_queues: "%{alias('swh::deploy::worker::loader_oneshot::task_queues')}"
+
 # for all loader packages
 swh::deploy::loader_core::sentry_swh_package: swh.loader.core
 swh::deploy::loader_core::sentry_environment: "%{hiera('swh::deploy::environment')}"
@@ -2383,7 +2399,7 @@
 swh::deploy::worker::loader_debian::loglevel: info
 swh::deploy::worker::loader_debian::config:
   storage: "%{alias('swh::deploy::worker::storage::pipeline')}"
-  max_content_size: 104857600
+  max_content_size: "%{alias('swh::deploy::worker::loader::max_content_size')}"
   celery:
     task_broker: "%{alias('swh::deploy::worker::task_broker')}"
     task_queues:
@@ -2395,7 +2411,7 @@
 swh::deploy::worker::loader_archive::loglevel: info
 swh::deploy::worker::loader_archive::config:
   storage: "%{alias('swh::deploy::worker::storage::pipeline')}"
-  max_content_size: 104857600
+  max_content_size: "%{alias('swh::deploy::worker::loader::max_content_size')}"
   celery:
     task_broker: "%{alias('swh::deploy::worker::task_broker')}"
     task_queues:
@@ -2407,7 +2423,7 @@
 swh::deploy::worker::loader_cran::loglevel: info
 swh::deploy::worker::loader_cran::config:
   storage: "%{alias('swh::deploy::worker::storage::pipeline')}"
-  max_content_size: 104857600
+  max_content_size: "%{alias('swh::deploy::worker::loader::max_content_size')}"
   celery:
     task_broker: "%{alias('swh::deploy::worker::task_broker')}"
     task_queues:
@@ -2419,7 +2435,7 @@
 swh::deploy::worker::loader_nixguix::loglevel: info
 swh::deploy::worker::loader_nixguix::config:
   storage: "%{alias('swh::deploy::worker::storage::pipeline')}"
-  max_content_size: 104857600
+  max_content_size: "%{alias('swh::deploy::worker::loader::max_content_size')}"
   celery:
     task_broker: "%{alias('swh::deploy::worker::task_broker')}"
     task_queues:
@@ -2489,7 +2505,7 @@
 swh::deploy::worker::loader_mercurial::loglevel: info
 swh::deploy::worker::loader_mercurial::config:
   storage: "%{alias('swh::deploy::worker::storage::pipeline')}"
-  max_content_size: 104857600
+  max_content_size: "%{alias('swh::deploy::worker::loader::max_content_size')}"
   reduce_effort: False
   clone_timeout_seconds: 7200
   celery:
@@ -2504,7 +2520,7 @@
 swh::deploy::worker::loader_pypi::loglevel: info
 swh::deploy::worker::loader_pypi::config:
   storage: "%{alias('swh::deploy::worker::storage::pipeline')}"
-  max_content_size: 104857600
+  max_content_size: "%{alias('swh::deploy::worker::loader::max_content_size')}"
   celery:
     task_broker: "%{alias('swh::deploy::worker::task_broker')}"
     task_queues:
@@ -2516,7 +2532,7 @@
 swh::deploy::worker::loader_npm::loglevel: info
 swh::deploy::worker::loader_npm::config:
   storage: "%{alias('swh::deploy::worker::storage::pipeline')}"
-  max_content_size: 104857600
+  max_content_size: "%{alias('swh::deploy::worker::loader::max_content_size')}"
   celery:
     task_broker: "%{alias('swh::deploy::worker::task_broker')}"
     task_queues:
@@ -2533,7 +2549,7 @@
 # Contains a password: in private data
 swh::deploy::worker::loader_svn::config:
   storage: "%{alias('swh::deploy::worker::storage::pipeline')}"
-  max_content_size: 104857600
+  max_content_size: "%{alias('swh::deploy::worker::loader::max_content_size')}"
   celery:
     task_broker: "%{alias('swh::deploy::worker::task_broker')}"
     task_queues:
diff --git a/data/hostname/worker17.softwareheritage.org.yaml b/data/hostname/worker17.softwareheritage.org.yaml
--- a/data/hostname/worker17.softwareheritage.org.yaml
+++ b/data/hostname/worker17.softwareheritage.org.yaml
@@ -1 +1,15 @@
-swh::deploy::worker::instances: []
+swh::deploy::worker::instances:
+  - loader_oneshot
+
+swh::deploy::worker::loader_oneshot::concurrency: 4
+swh::deploy::worker::loader_oneshot::task_queues:
+  # loader-git
+  - oneshot:swh.loader.git.tasks.UpdateGitRepository
+  # mercurial (not yet)
+  # - oneshot:swh.loader.mercurial.tasks.LoadMercurial
+  # - oneshot:swh.loader.mercurial.tasks.LoadArchiveMercurial
+  # svn
+  - oneshot:swh.loader.svn.tasks.LoadSvnRepository
+  - oneshot:swh.loader.svn.tasks.MountAndLoadSvnRepository
+  - oneshot:swh.loader.svn.tasks.DumpMountAndLoadSvnRepository
+
diff --git a/site-modules/profile/manifests/swh/deploy/worker/loader_oneshot.pp b/site-modules/profile/manifests/swh/deploy/worker/loader_oneshot.pp
new file mode 100644
--- /dev/null
+++ b/site-modules/profile/manifests/swh/deploy/worker/loader_oneshot.pp
@@ -0,0 +1,14 @@
+# Deployment for oneshot loader
+class profile::swh::deploy::worker::loader_oneshot {
+  include ::profile::swh::deploy::base_loader_git
+  include ::profile::swh::deploy::base_loader_mercurial
+  include ::profile::swh::deploy::base_loader_svn
+
+  $packages = $::profile::swh::deploy::base_loader_git::packages + $::profile::swh::deploy::base_loader_mercurial::packages + $::profile::swh::deploy::base_loader_svn::packages
+
+  ::profile::swh::deploy::worker::instance {'loader_oneshot':
+    ensure  => present,
+    require => Package[$packages],
+  }
+
+}