diff --git a/tests/buildkite/infrastructure/README.md b/tests/buildkite/infrastructure/README.md
new file mode 100644
index 000000000..cc3e552e7
--- /dev/null
+++ b/tests/buildkite/infrastructure/README.md
@@ -0,0 +1,106 @@
+BuildKite CI Infrastructure
+===========================
+
+# Worker image builder (`worker-image-pipeline/`)
+
+Use EC2 Image Builder to build machine images in a deterministic fashion.
+The machine images are used to initialize workers in the CI/CD pipelines.
+
+## Editing bootstrap scripts
+
+Currently, we create two pipelines for machine images: one for Linux workers and another
+for Windows workers.
+You can edit the bootstrap scripts to change how the worker machines are initialized.
+
+* `linux-amd64-gpu-bootstrap.yml`: Bootstrap script for Linux worker machines
+* `windows-gpu-bootstrap.yml`: Bootstrap script for Windows worker machines
+
+## Creating and running Image Builder pipelines
+
+Run the following commands to create and run pipelines in EC2 Image Builder service:
+```bash
+python worker-image-pipeline/create_worker_image_pipelines.py --aws-region us-west-2
+python worker-image-pipeline/run_pipelines.py --aws-region us-west-2
+```
+Go to the AWS CloudFormation console and verify the existence of two CloudFormation stacks:
+* `buildkite-windows-gpu-worker`
+* `buildkite-linux-amd64-gpu-worker`
+
+Then go to the EC2 Image Builder console to check the status of the image builds. You may
+want to inspect the log output should a build fails.
+Once the new machine images are done building, see the next section to deploy the new
+images to the worker machines.
+
+# Elastic CI Stack for AWS (`aws-stack-creator/`)
+
+Use EC2 Autoscaling groups to launch worker machines in EC2. BuildKite periodically sends
+messages to the Autoscaling groups to increase or decrease the number of workers according
+to the number of outstanding testing jobs.
+
+## Deploy an updated CI stack with new machine images
+
+First, edit `aws-stack-creator/metadata.py` to update the `AMI_ID` fields:
+```python
+AMI_ID = {
+    # Managed by XGBoost team
+    "linux-amd64-gpu": {
+        "us-west-2": "...",
+    },
+    "linux-amd64-mgpu": {
+        "us-west-2": "...",
+    },
+    "windows-gpu": {
+        "us-west-2": "...",
+    },
+    "windows-cpu": {
+        "us-west-2": "...",
+    },
+    # Managed by BuildKite
+    # from https://s3.amazonaws.com/buildkite-aws-stack/latest/aws-stack.yml
+    "linux-amd64-cpu": {
+        "us-west-2": "...",
+    },
+    "pipeline-loader": {
+        "us-west-2": "...",
+    },
+    "linux-arm64-cpu": {
+        "us-west-2": "...",
+    },
+}
+```
+AMI IDs uniquely identify the machine images in the EC2 service.
+Go to the EC2 Image Builder console to find the AMI IDs for the new machine images
+(see the previous section), and update the following fields:
+
+* `AMI_ID["linux-amd64-gpu"]["us-west-2"]`:
+  Use the latest output from the `buildkite-linux-amd64-gpu-worker` pipeline
+* `AMI_ID["linux-amd64-mgpu"]["us-west-2"]`:
+  Should be identical to `AMI_ID["linux-amd64-gpu"]["us-west-2"]`
+* `AMI_ID["windows-gpu"]["us-west-2"]`:
+  Use the latest output from the `buildkite-windows-gpu-worker` pipeline
+* `AMI_ID["windows-cpu"]["us-west-2"]`:
+  Should be identical to  `AMI_ID["windows-gpu"]["us-west-2"]`
+
+Next, visit https://s3.amazonaws.com/buildkite-aws-stack/latest/aws-stack.yml
+to look up the AMI IDs for the following fields:
+
+* `AMI_ID["linux-amd64-cpu"]["us-west-2"]`: Copy and paste the AMI ID from the field
+  `Mappings/AWSRegion2AMI/us-west-2/linuxamd64`
+* `AMI_ID["pipeline-loader"]["us-west-2"]`:
+   Should be identical to `AMI_ID["linux-amd64-cpu"]["us-west-2"]`
+* `AMI_ID["linux-arm64-cpu"]["us-west-2"]`: Copy and paste the AMI ID from the field
+  `Mappings/AWSRegion2AMI/us-west-2/linuxarm64`
+
+Finally, run the following commands to deploy the new machine images:
+```
+python aws-stack-creator/create_stack.py --aws-region us-west-2 --agent-token AGENT_TOKEN
+```
+Go to the AWS CloudFormation console and verify the existence of the following
+CloudFormation stacks:
+* `buildkite-pipeline-loader-autoscaling-group`
+* `buildkite-linux-amd64-cpu-autoscaling-group`
+* `buildkite-linux-amd64-gpu-autoscaling-group`
+* `buildkite-linux-amd64-mgpu-autoscaling-group`
+* `buildkite-linux-arm64-cpu-autoscaling-group`
+* `buildkite-windows-cpu-autoscaling-group`
+* `buildkite-windows-gpu-autoscaling-group`
diff --git a/tests/buildkite/infrastructure/aws-stack-creator/metadata.py b/tests/buildkite/infrastructure/aws-stack-creator/metadata.py
index 3b56a2d8c..e086021da 100644
--- a/tests/buildkite/infrastructure/aws-stack-creator/metadata.py
+++ b/tests/buildkite/infrastructure/aws-stack-creator/metadata.py
@@ -1,27 +1,27 @@
 AMI_ID = {
     # Managed by XGBoost team
     "linux-amd64-gpu": {
-        "us-west-2": "ami-08c3bc1dd5ec8bc5c",
+        "us-west-2": "ami-070080d04e81c5e39",
     },
     "linux-amd64-mgpu": {
-        "us-west-2": "ami-08c3bc1dd5ec8bc5c",
+        "us-west-2": "ami-070080d04e81c5e39",
     },
     "windows-gpu": {
-        "us-west-2": "ami-03c7f2156f93b22a7",
+        "us-west-2": "ami-07c14abcf529d816a",
     },
     "windows-cpu": {
-        "us-west-2": "ami-03c7f2156f93b22a7",
+        "us-west-2": "ami-07c14abcf529d816a",
     },
     # Managed by BuildKite
     # from https://s3.amazonaws.com/buildkite-aws-stack/latest/aws-stack.yml
     "linux-amd64-cpu": {
-        "us-west-2": "ami-015e64acb52b3e595",
+        "us-west-2": "ami-0180f7fb0f07eb0bc",
     },
     "pipeline-loader": {
-        "us-west-2": "ami-015e64acb52b3e595",
+        "us-west-2": "ami-0180f7fb0f07eb0bc",
     },
     "linux-arm64-cpu": {
-        "us-west-2": "ami-0884e9c23a2fa98d0",
+        "us-west-2": "ami-00686bdc2043a5505",
     },
 }
 
diff --git a/tests/buildkite/infrastructure/worker-image-pipeline/windows-gpu-bootstrap.yml b/tests/buildkite/infrastructure/worker-image-pipeline/windows-gpu-bootstrap.yml
index e4d212fda..128351e0d 100644
--- a/tests/buildkite/infrastructure/worker-image-pipeline/windows-gpu-bootstrap.yml
+++ b/tests/buildkite/infrastructure/worker-image-pipeline/windows-gpu-bootstrap.yml
@@ -15,9 +15,9 @@ phases:
               choco --version
               choco feature enable -n=allowGlobalConfirmation
 
-              # CMake 3.27
-              Write-Host '>>> Installing CMake 3.27...'
-              choco install cmake --version 3.27.9 --installargs "ADD_CMAKE_TO_PATH=System"
+              # CMake 3.29.2
+              Write-Host '>>> Installing CMake 3.29.2...'
+              choco install cmake --version 3.29.2 --installargs "ADD_CMAKE_TO_PATH=System"
               if ($LASTEXITCODE -ne 0) { throw "Last command failed" }
 
               # Notepad++
@@ -53,9 +53,9 @@ phases:
                   "--wait --passive --norestart --includeOptional"
               if ($LASTEXITCODE -ne 0) { throw "Last command failed" }
 
-              # Install CUDA 11.8
-              Write-Host '>>> Installing CUDA 11.8...'
-              choco install cuda --version=11.8.0.52206
+              # Install CUDA 12.4
+              Write-Host '>>> Installing CUDA 12.4...'
+              choco install cuda --version=12.4.1.551
               if ($LASTEXITCODE -ne 0) { throw "Last command failed" }
 
               # Install R