diff --git a/.github/workflows/docker-devito.yml b/.github/workflows/docker-devito.yml
index 95b70386c3..0d0c7bd73e 100644
--- a/.github/workflows/docker-devito.yml
+++ b/.github/workflows/docker-devito.yml
@@ -109,7 +109,6 @@ jobs:
           build-args: base=devitocodes/${{ matrix.base }}
 
       - name: Remove dangling layers
-        if: ${{ !contains(matrix.runner, 'nvidiagpu') }}
         run: docker system prune -f
 
       - name: Run tests
diff --git a/.github/workflows/pytest-gpu.yml b/.github/workflows/pytest-gpu.yml
index 2b8b25cf2c..2edb501dc3 100644
--- a/.github/workflows/pytest-gpu.yml
+++ b/.github/workflows/pytest-gpu.yml
@@ -15,18 +15,17 @@ concurrency:
   cancel-in-progress: true
 
 env:
-  OUTPUT_PATH: ${{ github.workspace }}
   RESOURCE_GROUP: CI-gpu
 
 on:
   push:
-    branches: [ main ]
+    branches: [main]
   pull_request:
-    branches: [ main ]
+    branches: [main]
   workflow_dispatch:
     inputs:
       tags:
-        description: 'Run GPU tests'
+        description: "Run GPU tests"
 
 jobs:
   build:
@@ -35,52 +34,41 @@ jobs:
       - self-hosted
       - ${{ matrix.runner_label }}
 
-    # Job-level env (includes per-runner image/container tags)
-    env:
-      DEVITO_ARCH: ${{ matrix.arch }}
-      DEVITO_PLATFORM: ${{ matrix.platform }}
-      DEVITO_LANGUAGE: ${{ matrix.language }}
-      OMPI_CC: ${{ matrix.arch }}
-
     strategy:
       fail-fast: false
       matrix:
-        name: [
-          pytest-gpu-acc-nvidia,
-          pytest-gpu-omp-amd
-        ]
+        name: [pytest-gpu-acc-nvidia, pytest-gpu-omp-amd]
         test_examples: ["examples/seismic/tti/tti_example.py examples/seismic/acoustic/acoustic_example.py examples/seismic/viscoacoustic/viscoacoustic_example.py examples/seismic/viscoelastic/viscoelastic_example.py examples/seismic/elastic/elastic_example.py"]
 
         include:
-        # -------------------- NVIDIA job --------------------
-        - name: pytest-gpu-acc-nvidia
-          test_files: "tests/test_adjoint.py tests/test_gpu_common.py tests/test_gpu_openacc.py"
-          base: "devitocodes/bases:nvidia-nvc"
-          runner_label: nvidiagpu
-          test_drive_cmd: "nvidia-smi"
-          # Respect CUDA_VISIBLE_DEVICES and also hard-limit Docker to that device.
-          # NOTE: CUDA_VISIBLE_DEVICES must be set by the runner (systemd drop-in etc.).
-          flags: >-
-            --init --rm -t
-            --name ${CONTAINER_BASENAME}
-            --env CUDA_VISIBLE_DEVICES
-            --gpus "device=${CUDA_VISIBLE_DEVICES:-all}"
-
-        # -------------------- AMD job -----------------------
-        - name: pytest-gpu-omp-amd
-          test_files: "tests/test_adjoint.py tests/test_gpu_common.py tests/test_gpu_openmp.py"
-          runner_label: amdgpu
-          base: "devitocodes/bases:amd"
-          test_drive_cmd: "rocm-smi"
-          # Unchanged, still passes through required /dev nodes etc.
-          flags: >-
-            --init --network=host
-            --device=/dev/kfd --device=/dev/dri
-            --ipc=host
-            --group-add video --group-add $(getent group render | cut -d: -f3)
-            --cap-add=SYS_PTRACE --security-opt seccomp=unconfined
-            --rm -t
-            --name ${CONTAINER_BASENAME}
+          # -------------------- NVIDIA job --------------------
+          - name: pytest-gpu-acc-nvidia
+            test_files: "tests/test_adjoint.py tests/test_gpu_common.py tests/test_gpu_openacc.py"
+            base: "devitocodes/bases:nvidia-nvc"
+            runner_label: nvidiagpu
+            test_drive_cmd: "nvidia-smi"
+            # Respect CUDA_VISIBLE_DEVICES and also hard-limit Docker to that device.
+            # NOTE: CUDA_VISIBLE_DEVICES must be set by the runner (systemd drop-in etc.).
+            flags: >-
+              --init --rm -t
+              --name ${CONTAINER_BASENAME}
+              --gpus "device=${CUDA_VISIBLE_DEVICES:-all}"
+
+          # -------------------- AMD job -----------------------
+          - name: pytest-gpu-omp-amd
+            test_files: "tests/test_adjoint.py tests/test_gpu_common.py tests/test_gpu_openmp.py"
+            runner_label: amdgpu
+            base: "devitocodes/bases:amd"
+            test_drive_cmd: "rocm-smi"
+            # Unchanged, still passes through required /dev nodes etc.
+            flags: >-
+              --init --network=host
+              --device=/dev/kfd --device=/dev/dri
+              --ipc=host
+              --group-add video --group-add "$(getent group render | cut -d: -f3)"
+              --cap-add=SYS_PTRACE --security-opt seccomp=unconfined
+              --rm -t
+              --name ${CONTAINER_BASENAME}
 
     steps:
       - name: Checkout devito
@@ -88,13 +76,21 @@ jobs:
 
       - name: Set per-runner tags
         run: |
-          echo "RUNNER_NAME=$RUNNER_NAME" >> $GITHUB_ENV
           echo "DOCKER_IMAGE=${{ matrix.name }}-${RUNNER_NAME// /_}" >> $GITHUB_ENV
           echo "CONTAINER_BASENAME=testrun-${{ matrix.name }}-${RUNNER_NAME// /_}" >> $GITHUB_ENV
 
+      - name: Ensure buildx builder
+        run: |
+          docker buildx inspect "${RUNNER_NAME// /_}" >/dev/null 2>&1 || \
+            docker buildx create --name "${RUNNER_NAME// /_}" --driver docker-container
+          docker buildx use "${RUNNER_NAME// /_}"
+
       - name: Build docker image
         run: |
-          docker build . \
+          docker buildx build . \
+            --builder "${RUNNER_NAME// /_}" \
+            --load \
+            --label ci-run=$GITHUB_RUN_ID \
             --rm --pull \
             --file docker/Dockerfile.devito \
             --tag "${DOCKER_IMAGE}" \
@@ -105,16 +101,37 @@ jobs:
 
       - name: Probe gpu
         run: |
-          # Run a simple driver cmd first (nvidia-smi / rocm-smi)
+          # Make sure CUDA_VISIBLE_DEVICES is at least *something* on NVIDIA
+          # runners; fall back to "all" so the driver probe does not fail.
+          if [[ "${{ matrix.runner_label }}" == "nvidiagpu" && -z "${CUDA_VISIBLE_DEVICES:-}" ]]; then
+            echo "CUDA_VISIBLE_DEVICES=all" >> $GITHUB_ENV
+          fi
+
+          # Run a simple driver-probe command (nvidia-smi / rocm-smi)
+          docker rm -f "${CONTAINER_BASENAME}" 2>/dev/null || true
           docker run ${{ matrix.flags }} "${DOCKER_IMAGE}" ${{ matrix.test_drive_cmd }}
 
       - name: Test with pytest
+        env:
+          # Exported earlier in the job; needed inside the container for codecov
+          CODECOV_TOKEN: ${{ env.CODECOV_TOKEN }}
         run: |
-          # Run a simple driver cmd first (nvidia-smi / rocm-smi)
+          # Add Codecov’s environment variables (GITHUB_SHA, etc.)
           ci_env=$(bash <(curl -s https://codecov.io/env))
 
-          docker run ${{ matrix.flags }} $ci_env -e CI=true "${DOCKER_IMAGE}" \
-            pytest --cov --cov-config=.coveragerc --cov-report=xml ${{ matrix.test_files }}
+          # Run the test suite using the matrix-defined flags
+          docker run ${{ matrix.flags }} \
+            ${ci_env} \
+            -e CI=true \
+            -e PYTHONFAULTHANDLER=1 \
+            -e DEVITO_LOGGING=DEBUG \
+            -e CODECOV_TOKEN \
+            "${DOCKER_IMAGE}" \
+            pytest -vvv --capture=no --showlocals \
+                   --log-cli-level=DEBUG -o log_cli=true \
+                   --full-trace --durations=10 \
+                   --cov --cov-config=.coveragerc --cov-report=xml \
+                   ${{ matrix.test_files }}
 
       - name: Test examples
         run: |
@@ -124,3 +141,17 @@ jobs:
         run: |
           docker run ${{ matrix.flags }} --env DEVITO_MPI=1 "${DOCKER_IMAGE}" \
             mpiexec -n 2 pytest ${{ matrix.test_examples }}
+
+      - name: Builder & image cleanup (keep 3 days of cache)
+        if: always()
+        run: |
+          # Remove only the test image we built
+          docker rmi -f "${DOCKER_IMAGE}" || true
+
+          # Classic image layers created in this job
+          docker image prune -f --filter label=ci-run=$GITHUB_RUN_ID
+
+          # BuildKit cache: target the per-runner builder explicitly
+          docker builder prune --builder "${RUNNER_NAME// /_}" \
+                              -f \
+                              --filter "until=72h"