diff --git a/.gitignore b/.gitignore
index 5c34fde1..7a555744 100644
--- a/.gitignore
+++ b/.gitignore
@@ -20,6 +20,10 @@ flamenco-worker.yaml
 flamenco-worker-credentials.yaml
 node_modules/
 
+# Directories used to store go and yarn dependencies for offline building
+/vendor
+/web/app/package-cache
+
 # Directory for custom job compiler scripts:
 /scripts/
 
diff --git a/Makefile b/Makefile
index e82ce733..2f2c4dbf 100644
--- a/Makefile
+++ b/Makefile
@@ -46,17 +46,14 @@ export CGO_ENABLED=0
 
 all: application
 
-# Install generators and build the software.
-with-deps:
-	go install github.com/deepmap/oapi-codegen/cmd/oapi-codegen@v1.9.0
-	go install github.com/golang/mock/mockgen@v1.6.0
-	$(MAKE) application
+vendor: webapp-deps
+	go mod vendor
 
 vet:
 	go vet ./...
 	go run golang.org/x/vuln/cmd/govulncheck@latest ./...
 
-application: webapp flamenco-manager flamenco-worker
+application: flamenco-manager flamenco-worker
 
 flamenco-manager:
 	$(MAKE) webapp-static
@@ -93,10 +90,11 @@ flamenco-worker_race:
 shaman-checkout-id-setter:
 	go build -v ${BUILD_FLAGS} ${PKG}/cmd/shaman-checkout-id-setter
 
-webapp:
-	yarn --cwd web/app install
+webapp-deps:
+	# We have to use --force here to ensure that the offline package cache is up to date with no missing files
+	yarn --cwd web/app install --force
 
-webapp-static: addon-packer
+webapp-static: webapp-deps addon-packer
 	$(MAKE) clean-webapp-static
 # When changing the base URL, also update the line
 # e.GET("/app/*", echo.WrapHandler(webAppHandler))
@@ -331,6 +329,9 @@ RELEASE_PACKAGE_WINDOWS := flamenco-${VERSION}-windows-amd64.zip
 RELEASE_PACKAGE_EXTRA_FILES := README.md LICENSE CHANGELOG.md
 RELEASE_PACKAGE_SHAFILE := flamenco-${VERSION}.sha256
 
+RELEASE_SOURCE_ARCHIVE := flamenco-${VERSION}-src.tar
+RELEASE_SOURCE_ARCHIVE_GZ := flamenco-${VERSION}-src.tar.gz
+
 .PHONY: release-package
 release-package:
 	$(MAKE) -s release-package-linux
@@ -377,12 +378,21 @@ release-package-windows:
 	zip -r -9 dist/${RELEASE_PACKAGE_WINDOWS} flamenco-manager.exe flamenco-worker.exe ${RELEASE_PACKAGE_EXTRA_FILES} tools/*-windows*
 	@echo "Done! Created ${RELEASE_PACKAGE_WINDOWS}"
 
+.PHONY: release-package-source
+release-package-source: vendor
+	mkdir -p dist
+	rm -f dist/${RELEASE_SOURCE_ARCHIVE_GZ}
+	git archive --prefix=flamenco-${VERSION}/ -o dist/${RELEASE_SOURCE_ARCHIVE} HEAD
+	tar --transform 's,^,flamenco-${VERSION}/,' -rvf dist/${RELEASE_SOURCE_ARCHIVE} vendor web/app/package-cache
+	gzip dist/${RELEASE_SOURCE_ARCHIVE}
+	@echo "Done! Created ${RELEASE_SOURCE_ARCHIVE_GZ}"
+
 .PHONY: publish-release-packages
 publish-release-packages:
 	$(MAKE) -s check-environment
-	cd dist; sha256sum ${RELEASE_PACKAGE_LINUX} ${RELEASE_PACKAGE_DARWIN} ${RELEASE_PACKAGE_WINDOWS} > ${RELEASE_PACKAGE_SHAFILE}
+	cd dist; sha256sum ${RELEASE_PACKAGE_LINUX} ${RELEASE_PACKAGE_DARWIN} ${RELEASE_PACKAGE_WINDOWS} ${RELEASE_SOURCE_ARCHIVE_GZ} > ${RELEASE_PACKAGE_SHAFILE}
 	cd dist; rsync -va \
-		${RELEASE_PACKAGE_LINUX} ${RELEASE_PACKAGE_DARWIN} ${RELEASE_PACKAGE_WINDOWS} ${RELEASE_PACKAGE_SHAFILE} \
+		${RELEASE_PACKAGE_LINUX} ${RELEASE_PACKAGE_DARWIN} ${RELEASE_PACKAGE_WINDOWS} ${RELEASE_SOURCE_ARCHIVE_GZ} ${RELEASE_PACKAGE_SHAFILE} \
 		${WEBSERVER_SSH}:${WEBSERVER_ROOT}/downloads/
 
-.PHONY: application version flamenco-manager flamenco-worker flamenco-manager_race flamenco-worker_race webapp webapp-static generate generate-go generate-py with-deps swagger-ui list-embedded test clean clean-webapp-static
+.PHONY: application version flamenco-manager flamenco-worker flamenco-manager_race flamenco-worker_race webapp-deps webapp-static generate generate-go generate-py vendor swagger-ui list-embedded test clean clean-webapp-static
diff --git a/web/app/.yarnrc b/web/app/.yarnrc
new file mode 100644
index 00000000..4f5f5ec5
--- /dev/null
+++ b/web/app/.yarnrc
@@ -0,0 +1,2 @@
+yarn-offline-mirror "./package-cache"
+yarn-offline-mirror-pruning true