diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 66763b7..3de20d9 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,7 +12,7 @@ jobs:
   build-sim:
     runs-on: ubuntu-latest
     container:
-        image: tryspaceorg/tryspace-lab
+        image: tryspaceorg/tryspace-lab:0.0.0
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
@@ -26,7 +26,7 @@ jobs:
   build-test:
     runs-on: ubuntu-latest
     container:
-        image: tryspaceorg/tryspace-lab
+        image: tryspaceorg/tryspace-lab:0.0.0
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
diff --git a/Makefile b/Makefile
index 187cbcf..a0bc777 100644
--- a/Makefile
+++ b/Makefile
@@ -4,14 +4,19 @@
 export BUILDDIR ?= $(CURDIR)/build
 export TOPDIR ?= $(CURDIR)/..
 
-export BUILD_IMAGE ?= tryspaceorg/tryspace-lab
+export BUILD_IMAGE ?= tryspaceorg/tryspace-lab:0.0.0
 export CONTAINER_NAME ?= tryspace-lab
 export RUNTIME_DIRECTOR_NAME ?= tryspace-director
 export RUNTIME_SERVER_NAME ?= tryspace-server
 
+# Determine number of parallel jobs to avoid maxing out low-power systems (Raspberry Pi etc.).
+# Use `nproc - 1` but ensure at least 1 job.
+NPROC := $(shell nproc 2>/dev/null || echo 1)
+JOBS := $(shell if [ $(NPROC) -le 1 ]; then echo 1; else expr $(NPROC) - 1; fi)
+
 # Commands
 build:
-	docker run --rm -v $(TOPDIR):$(TOPDIR) --user $(shell id -u):$(shell id -g) --name $(CONTAINER_NAME) -w $(CURDIR) $(BUILD_IMAGE) make -j build-sim
+	docker run --rm -v $(TOPDIR):$(TOPDIR) --user $(shell id -u):$(shell id -g) --name $(CONTAINER_NAME) -w $(CURDIR) $(BUILD_IMAGE) make -j$(JOBS) build-sim
 
 build-director: 
 	mkdir -p $(BUILDDIR)
@@ -58,4 +63,4 @@ stop:
 	docker ps --filter name=tryspace-* | xargs docker stop
 
 test:
-	docker run --rm -v $(TOPDIR):$(TOPDIR) --user $(shell id -u):$(shell id -g) --name $(CONTAINER_NAME) -w $(CURDIR) $(BUILD_IMAGE) make -j build-test
+	docker run --rm -v $(TOPDIR):$(TOPDIR) --user $(shell id -u):$(shell id -g) --name $(CONTAINER_NAME) -w $(CURDIR) $(BUILD_IMAGE) make -j$(JOBS) build-test
diff --git a/test/Dockerfile.director b/test/Dockerfile.director
index 0e2f8f0..ec9eb2e 100644
--- a/test/Dockerfile.director
+++ b/test/Dockerfile.director
@@ -1,4 +1,4 @@
-FROM tryspaceorg/tryspace-lab:latest
+FROM tryspaceorg/tryspace-lab:0.0.0
 
 # Copy built simulith director and components
 COPY ./build/simulith_director_standalone /app/simulith_director_standalone
diff --git a/test/Dockerfile.server b/test/Dockerfile.server
index 92b40fc..ccf512c 100644
--- a/test/Dockerfile.server
+++ b/test/Dockerfile.server
@@ -1,4 +1,4 @@
-FROM tryspaceorg/tryspace-lab:latest
+FROM tryspaceorg/tryspace-lab:0.0.0
 
 # Copy built FSW files into the image
 COPY build /app