diff --git a/.github/workflows-source/ci-main.yml b/.github/workflows-source/ci-main.yml
index 94cdc0f6a1b..c24bdc9bb0f 100644
--- a/.github/workflows-source/ci-main.yml
+++ b/.github/workflows-source/ci-main.yml
@@ -112,16 +112,32 @@ jobs:
         shell: bash
         run: |
           set -xeuo pipefail
+
+          # Determine which tests to skip and append 'long_test' for pull requests or merge groups
+          EXCLUDED_TEST_TAGS=(system_test_hourly system_test_nightly system_test_nightly_nns system_test_staging system_test_hotfix system_test_benchmark fuzz_test fi_tests_nightly nns_tests_nightly)
+          [[ "${{ github.event_name }}" =~ ^(pull_request|merge_group)$ ]] && EXCLUDED_TEST_TAGS+=(long_test)
+
+          # Export excluded tags as environment variable for ci/bazel-scripts/diff.sh
+          echo "EXCLUDED_TEST_TAGS=${EXCLUDED_TEST_TAGS[*]}" >> $GITHUB_ENV
+
+          # Prepend tags with '-' and join them with commas for Bazel
+          TEST_TAG_FILTERS=$(IFS=,; echo "${EXCLUDED_TEST_TAGS[*]/#/-}")
+
+          # Determine BAZEL_EXTRA_ARGS based on event type or branch name
+          BAZEL_EXTRA_ARGS="--test_tag_filters=$TEST_TAG_FILTERS"
           if [[ "${{ github.event_name }}" == 'merge_group' ]]; then
-            echo "BAZEL_EXTRA_ARGS=--test_timeout_filters=short,moderate --flaky_test_attempts=3" >> $GITHUB_ENV
+              BAZEL_EXTRA_ARGS+=" --test_timeout_filters=short,moderate --flaky_test_attempts=3"
           elif [[ $BRANCH_NAME =~ ^hotfix-.* ]]; then
-            echo "BAZEL_EXTRA_ARGS=--test_timeout_filters=short,moderate" >> $GITHUB_ENV
+              BAZEL_EXTRA_ARGS+=" --test_timeout_filters=short,moderate"
           else
-            echo "BAZEL_EXTRA_ARGS=--keep_going" >> $GITHUB_ENV
+              BAZEL_EXTRA_ARGS+=" --keep_going"
           fi
+
+          # Export BAZEL_EXTRA_ARGS to environment
+          echo "BAZEL_EXTRA_ARGS=$BAZEL_EXTRA_ARGS" >> $GITHUB_ENV
       - name: Run Bazel Test All
         id: bazel-test-all
-        uses:  ./.github/actions/bazel-test-all/
+        uses: ./.github/actions/bazel-test-all/
         env:
           AWS_SHARED_CREDENTIALS_CONTENT: ${{ secrets.AWS_SHARED_CREDENTIALS_FILE }}
           # Only run ci/bazel-scripts/diff.sh on PRs that are not labeled with "CI_ALL_BAZEL_TARGETS".
diff --git a/.github/workflows/ci-main.yml b/.github/workflows/ci-main.yml
index 57e6519474c..2944e62ccbc 100644
--- a/.github/workflows/ci-main.yml
+++ b/.github/workflows/ci-main.yml
@@ -58,13 +58,29 @@ jobs:
         shell: bash
         run: |
           set -xeuo pipefail
+
+          # Determine which tests to skip and append 'long_test' for pull requests or merge groups
+          EXCLUDED_TEST_TAGS=(system_test_hourly system_test_nightly system_test_nightly_nns system_test_staging system_test_hotfix system_test_benchmark fuzz_test fi_tests_nightly nns_tests_nightly)
+          [[ "${{ github.event_name }}" =~ ^(pull_request|merge_group)$ ]] && EXCLUDED_TEST_TAGS+=(long_test)
+
+          # Export excluded tags as environment variable for ci/bazel-scripts/diff.sh
+          echo "EXCLUDED_TEST_TAGS=${EXCLUDED_TEST_TAGS[*]}" >> $GITHUB_ENV
+
+          # Prepend tags with '-' and join them with commas for Bazel
+          TEST_TAG_FILTERS=$(IFS=,; echo "${EXCLUDED_TEST_TAGS[*]/#/-}")
+
+          # Determine BAZEL_EXTRA_ARGS based on event type or branch name
+          BAZEL_EXTRA_ARGS="--test_tag_filters=$TEST_TAG_FILTERS"
           if [[ "${{ github.event_name }}" == 'merge_group' ]]; then
-            echo "BAZEL_EXTRA_ARGS=--test_timeout_filters=short,moderate --flaky_test_attempts=3" >> $GITHUB_ENV
+              BAZEL_EXTRA_ARGS+=" --test_timeout_filters=short,moderate --flaky_test_attempts=3"
           elif [[ $BRANCH_NAME =~ ^hotfix-.* ]]; then
-            echo "BAZEL_EXTRA_ARGS=--test_timeout_filters=short,moderate" >> $GITHUB_ENV
+              BAZEL_EXTRA_ARGS+=" --test_timeout_filters=short,moderate"
           else
-            echo "BAZEL_EXTRA_ARGS=--keep_going" >> $GITHUB_ENV
+              BAZEL_EXTRA_ARGS+=" --keep_going"
           fi
+
+          # Export BAZEL_EXTRA_ARGS to environment
+          echo "BAZEL_EXTRA_ARGS=$BAZEL_EXTRA_ARGS" >> $GITHUB_ENV
       - name: Run Bazel Test All
         id: bazel-test-all
         uses: ./.github/actions/bazel-test-all/
diff --git a/bazel/conf/.bazelrc.build b/bazel/conf/.bazelrc.build
index e4ed1fe31db..0493d9ab452 100644
--- a/bazel/conf/.bazelrc.build
+++ b/bazel/conf/.bazelrc.build
@@ -54,12 +54,11 @@ build --flag_alias=timeout_value=//bazel:timeout_value
 # Exclude system tests by default
 # https://github.com/bazelbuild/bazel/issues/8439
 build --build_tag_filters="-system_test,-upload,-fuzz_test"
-test --test_tag_filters="-system_test,-post_master,-fuzz_test"
+test --test_tag_filters="-system_test,-fuzz_test"
 test:alltests --test_tag_filters=""
 test:paritytests --test_tag_filters="-system_test"
 build:ci --build_tag_filters="-system_test,-fuzz_test"
 build:ci --verbose_failures
-test:ci --test_tag_filters="-post_master,-system_test_hourly,-system_test_nightly,-system_test_nightly_nns,-system_test_staging,-system_test_hotfix,-system_test_benchmark,-fuzz_test,-fi_tests_nightly,-nns_tests_nightly"
 
 test --test_output=errors
 test --test_env=RUST_BACKTRACE=full
diff --git a/ci/bazel-scripts/diff.sh b/ci/bazel-scripts/diff.sh
index 08cd00a8220..60c13fdb816 100755
--- a/ci/bazel-scripts/diff.sh
+++ b/ci/bazel-scripts/diff.sh
@@ -55,7 +55,12 @@ fi
 if [ "${BAZEL_COMMAND:-}" == "build" ]; then
     TARGETS=$(bazel query "rdeps(//..., set(${files[*]}))")
 elif [ "${BAZEL_COMMAND:-}" == "test" ]; then
-    TARGETS=$(bazel query "kind(test, rdeps(//..., set(${files[*]}))) except attr('tags', 'manual|system_test_hourly|system_test_nightly|system_test_staging|system_test_hotfix|system_test_nightly_nns', //...)")
+    EXCLUDED_TAGS=(manual $EXCLUDED_TEST_TAGS)
+    EXCLUDED_TAGS=$(
+        IFS='|'
+        echo "${EXCLUDED_TAGS[*]}"
+    )
+    TARGETS=$(bazel query "kind(test, rdeps(//..., set(${files[*]}))) except attr('tags', '$EXCLUDED_TAGS', //...)")
 else
     echo "Unknown BAZEL_COMMAND: ${BAZEL_COMMAND:-}" >&2
     exit 1
diff --git a/rs/ethereum/ledger-suite-orchestrator/BUILD.bazel b/rs/ethereum/ledger-suite-orchestrator/BUILD.bazel
index c82286bfe4f..4900a372be3 100644
--- a/rs/ethereum/ledger-suite-orchestrator/BUILD.bazel
+++ b/rs/ethereum/ledger-suite-orchestrator/BUILD.bazel
@@ -161,6 +161,9 @@ rust_ic_test(
         "LEDGER_ARCHIVE_NODE_CANISTER_WASM_PATH": "$(rootpath //rs/ledger_suite/icrc1/archive:archive_canister_u256.wasm.gz)",
     },
     proc_macro_deps = [],
+    tags = [
+        "long_test",  # since it takes longer than 5 minutes.
+    ],
     deps = [
         # Keep sorted.
         ":ledger_suite_orchestrator",
diff --git a/rs/tests/boundary_nodes/BUILD.bazel b/rs/tests/boundary_nodes/BUILD.bazel
index a626c2b04fe..46aa5b0e7f9 100644
--- a/rs/tests/boundary_nodes/BUILD.bazel
+++ b/rs/tests/boundary_nodes/BUILD.bazel
@@ -19,10 +19,12 @@ system_test_nns(
         "HTTP_COUNTER_WASM_PATH": "$(rootpath //rs/tests/test_canisters/http_counter)",
         "ASSET_CANISTER_WASM_PATH": "$(rootpath @asset_canister//file)",
     },
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = BOUNDARY_NODE_GUESTOS_RUNTIME_DEPS + GUESTOS_RUNTIME_DEPS + TEST_CANISTERS_RUNTIME_DEPS + GRAFANA_RUNTIME_DEPS,
@@ -196,10 +198,12 @@ system_test_nns(
 
 system_test_nns(
     name = "api_bn_decentralization_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = BOUNDARY_NODE_GUESTOS_RUNTIME_DEPS + GUESTOS_RUNTIME_DEPS + GRAFANA_RUNTIME_DEPS,
diff --git a/rs/tests/consensus/BUILD.bazel b/rs/tests/consensus/BUILD.bazel
index 52b0842abcc..21b98ddc24a 100644
--- a/rs/tests/consensus/BUILD.bazel
+++ b/rs/tests/consensus/BUILD.bazel
@@ -199,11 +199,13 @@ system_test_nns(
 
 system_test_nns(
     name = "subnet_splitting_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "experimental_system_test_colocation",
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
         "subnet_splitting",
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
@@ -345,10 +347,12 @@ system_test_nns(
 
 system_test_nns(
     name = "adding_nodes_to_subnet_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = GUESTOS_RUNTIME_DEPS,
diff --git a/rs/tests/consensus/backup/BUILD.bazel b/rs/tests/consensus/backup/BUILD.bazel
index d482a431f02..21526950eae 100644
--- a/rs/tests/consensus/backup/BUILD.bazel
+++ b/rs/tests/consensus/backup/BUILD.bazel
@@ -31,11 +31,12 @@ BACKUP_RUNTIME_DEPS = ["//rs/tests:backup/binaries"]
 
 system_test_nns(
     name = "backup_manager_downgrade_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "experimental_system_test_colocation",
-        "system_test_hourly",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     uses_guestos_dev_test = True,
@@ -54,11 +55,12 @@ system_test_nns(
 
 system_test_nns(
     name = "backup_manager_upgrade_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "experimental_system_test_colocation",
-        "system_test_hourly",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     uses_guestos_dev_test = True,
diff --git a/rs/tests/consensus/orchestrator/BUILD.bazel b/rs/tests/consensus/orchestrator/BUILD.bazel
index 450eab6b9d2..aef4eafcb19 100644
--- a/rs/tests/consensus/orchestrator/BUILD.bazel
+++ b/rs/tests/consensus/orchestrator/BUILD.bazel
@@ -5,10 +5,12 @@ package(default_visibility = ["//rs:system-tests-pkg"])
 
 system_test_nns(
     name = "node_assign_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = GUESTOS_RUNTIME_DEPS,
@@ -31,10 +33,12 @@ system_test_nns(
 
 system_test_nns(
     name = "node_reassignment_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = GUESTOS_RUNTIME_DEPS,
@@ -96,10 +100,12 @@ system_test(
 
 system_test_nns(
     name = "ssh_access_to_nodes_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = GUESTOS_RUNTIME_DEPS,
@@ -138,10 +144,12 @@ system_test_nns(
 
 system_test_nns(
     name = "rotate_ecdsa_idkg_key_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = GUESTOS_RUNTIME_DEPS,
diff --git a/rs/tests/consensus/subnet_recovery/BUILD.bazel b/rs/tests/consensus/subnet_recovery/BUILD.bazel
index f596b57741f..276eaedb262 100644
--- a/rs/tests/consensus/subnet_recovery/BUILD.bazel
+++ b/rs/tests/consensus/subnet_recovery/BUILD.bazel
@@ -47,11 +47,13 @@ rust_library(
 
 system_test_nns(
     name = "sr_app_same_nodes_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "experimental_system_test_colocation",
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
         "subnet_recovery",
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
@@ -106,11 +108,13 @@ system_test_nns(
 
 system_test_nns(
     name = "sr_app_failover_nodes_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "experimental_system_test_colocation",
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
         "subnet_recovery",
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
@@ -167,11 +171,13 @@ system_test_nns(
 
 system_test_nns(
     name = "sr_app_no_upgrade_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "experimental_system_test_colocation",
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
         "subnet_recovery",
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
@@ -250,11 +256,13 @@ system_test_nns(
 
 system_test_nns(
     name = "sr_nns_same_nodes_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "experimental_system_test_colocation",
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
         "subnet_recovery",
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
@@ -274,11 +282,13 @@ system_test_nns(
 
 system_test_nns(
     name = "sr_nns_failover_nodes_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = False,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "experimental_system_test_colocation",
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
         "subnet_recovery",
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
diff --git a/rs/tests/consensus/tecdsa/BUILD.bazel b/rs/tests/consensus/tecdsa/BUILD.bazel
index ea26ba0a6ca..012c5a9fbbd 100644
--- a/rs/tests/consensus/tecdsa/BUILD.bazel
+++ b/rs/tests/consensus/tecdsa/BUILD.bazel
@@ -31,10 +31,12 @@ system_test_nns(
 
 system_test_nns(
     name = "tecdsa_add_nodes_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = GUESTOS_RUNTIME_DEPS,
@@ -58,10 +60,12 @@ system_test_nns(
 
 system_test_nns(
     name = "tschnorr_message_sizes_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = GUESTOS_RUNTIME_DEPS,
@@ -81,10 +85,12 @@ system_test_nns(
 
 system_test_nns(
     name = "tecdsa_remove_nodes_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = GUESTOS_RUNTIME_DEPS,
@@ -224,11 +230,13 @@ system_test_nns(
 
 system_test_nns(
     name = "tecdsa_signature_life_cycle_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     # Remove when CON-937 is resolved
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = GUESTOS_RUNTIME_DEPS,
@@ -273,10 +281,12 @@ system_test_nns(
 
 system_test_nns(
     name = "tecdsa_signature_timeout_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = GUESTOS_RUNTIME_DEPS,
diff --git a/rs/tests/consensus/upgrade/BUILD.bazel b/rs/tests/consensus/upgrade/BUILD.bazel
index 46d94e22ff6..f58d15bd133 100644
--- a/rs/tests/consensus/upgrade/BUILD.bazel
+++ b/rs/tests/consensus/upgrade/BUILD.bazel
@@ -84,8 +84,12 @@ system_test_nns(
 
 system_test_nns(
     name = "upgrade_app_subnet_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
+    tags = [
+        "long_test",  # since it takes longer than 5 minutes.
+    ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     uses_guestos_dev_test = True,
     runtime_deps =
@@ -107,8 +111,12 @@ system_test_nns(
 
 system_test_nns(
     name = "downgrade_app_subnet_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
+    tags = [
+        "long_test",  # since it takes longer than 5 minutes.
+    ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     uses_guestos_dev_test = True,
     runtime_deps =
diff --git a/rs/tests/financial_integrations/ckbtc/BUILD.bazel b/rs/tests/financial_integrations/ckbtc/BUILD.bazel
index 3047b6e4449..46808d61753 100644
--- a/rs/tests/financial_integrations/ckbtc/BUILD.bazel
+++ b/rs/tests/financial_integrations/ckbtc/BUILD.bazel
@@ -19,10 +19,12 @@ system_test_nns(
         "LEDGER_WASM_PATH": "$(rootpath //rs/ledger_suite/icrc1/ledger:ledger_canister)",
         "BTC_WASM_PATH": "$(rootpath @btc_canister//file)",
     },
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
@@ -44,6 +46,7 @@ system_test_nns(
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
@@ -65,6 +68,7 @@ system_test_nns(
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
@@ -82,10 +86,12 @@ system_test_nns(
         "LEDGER_WASM_PATH": "$(rootpath //rs/ledger_suite/icrc1/ledger:ledger_canister)",
         "BTC_WASM_PATH": "$(rootpath @btc_canister//file)",
     },
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
@@ -103,10 +109,12 @@ system_test_nns(
         "LEDGER_WASM_PATH": "$(rootpath //rs/ledger_suite/icrc1/ledger:ledger_canister)",
         "BTC_WASM_PATH": "$(rootpath @btc_canister//file)",
     },
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
@@ -124,10 +132,12 @@ system_test_nns(
         "LEDGER_WASM_PATH": "$(rootpath //rs/ledger_suite/icrc1/ledger:ledger_canister)",
         "BTC_WASM_PATH": "$(rootpath @btc_canister//file)",
     },
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
diff --git a/rs/tests/financial_integrations/rosetta/BUILD.bazel b/rs/tests/financial_integrations/rosetta/BUILD.bazel
index eaeedae0b9a..d178e18e50c 100644
--- a/rs/tests/financial_integrations/rosetta/BUILD.bazel
+++ b/rs/tests/financial_integrations/rosetta/BUILD.bazel
@@ -40,10 +40,12 @@ system_test_nns(
 
 system_test_nns(
     name = "rosetta_make_transactions_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
@@ -78,10 +80,12 @@ system_test_nns(
 
 system_test_nns(
     name = "rosetta_neuron_disburse_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
@@ -101,6 +105,7 @@ system_test_nns(
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
@@ -116,10 +121,12 @@ system_test_nns(
 
 system_test_nns(
     name = "rosetta_neuron_follow_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
@@ -135,10 +142,12 @@ system_test_nns(
 
 system_test_nns(
     name = "rosetta_neuron_hotkey_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
@@ -154,10 +163,12 @@ system_test_nns(
 
 system_test_nns(
     name = "rosetta_neuron_info_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
@@ -173,10 +184,12 @@ system_test_nns(
 
 system_test_nns(
     name = "rosetta_neuron_maturity_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
@@ -192,10 +205,12 @@ system_test_nns(
 
 system_test_nns(
     name = "rosetta_neuron_spawn_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
@@ -211,10 +226,12 @@ system_test_nns(
 
 system_test_nns(
     name = "rosetta_neuron_staking_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
@@ -230,10 +247,12 @@ system_test_nns(
 
 system_test_nns(
     name = "rosetta_neuron_voting_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
diff --git a/rs/tests/networking/BUILD.bazel b/rs/tests/networking/BUILD.bazel
index e99525241bf..d9b3097bbc8 100644
--- a/rs/tests/networking/BUILD.bazel
+++ b/rs/tests/networking/BUILD.bazel
@@ -27,9 +27,13 @@ system_test_nns(
     env = {
         "PROXY_WASM_PATH": "$(rootpath //rs/rust_canisters/proxy_canister:proxy_canister)",
     },
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
-    tags = ["k8s"],
+    tags = [
+        "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
+    ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
         GUESTOS_RUNTIME_DEPS +
@@ -68,9 +72,13 @@ system_test_nns(
     env = {
         "PROXY_WASM_PATH": "$(rootpath //rs/rust_canisters/proxy_canister:proxy_canister)",
     },
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
     proc_macro_deps = MACRO_DEPENDENCIES,
-    tags = ["k8s"],
+    tags = [
+        "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
+    ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps =
         GUESTOS_RUNTIME_DEPS +
diff --git a/rs/tests/nns/BUILD.bazel b/rs/tests/nns/BUILD.bazel
index 6ba3377fbb0..ad48112dee8 100644
--- a/rs/tests/nns/BUILD.bazel
+++ b/rs/tests/nns/BUILD.bazel
@@ -126,6 +126,7 @@ system_test(
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = GUESTOS_RUNTIME_DEPS + NNS_CANISTER_RUNTIME_DEPS,
diff --git a/rs/tests/query_stats/BUILD.bazel b/rs/tests/query_stats/BUILD.bazel
index 4252753c226..7877dce5905 100644
--- a/rs/tests/query_stats/BUILD.bazel
+++ b/rs/tests/query_stats/BUILD.bazel
@@ -23,6 +23,7 @@ system_test(
     proc_macro_deps = MACRO_DEPENDENCIES,
     tags = [
         "k8s",
+        "long_test",  # since it takes longer than 5 minutes.
     ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = GUESTOS_RUNTIME_DEPS + GRAFANA_RUNTIME_DEPS,
diff --git a/rs/tests/sdk/BUILD.bazel b/rs/tests/sdk/BUILD.bazel
index fc31cd6d482..56c79e0f7fe 100644
--- a/rs/tests/sdk/BUILD.bazel
+++ b/rs/tests/sdk/BUILD.bazel
@@ -35,7 +35,11 @@ BOUNDARY_NODE_RUNTIME_DEPS = BOUNDARY_NODE_GUESTOS_RUNTIME_DEPS + [
 
 system_test_nns(
     name = "dfx_smoke_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
+    tags = [
+        "long_test",  # since it takes longer than 5 minutes.
+    ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = RUNTIME_DEPS + BOUNDARY_NODE_RUNTIME_DEPS,
     deps = [
diff --git a/rs/tests/testing_verification/BUILD.bazel b/rs/tests/testing_verification/BUILD.bazel
index 7d038702f19..0e51bd1b5ca 100644
--- a/rs/tests/testing_verification/BUILD.bazel
+++ b/rs/tests/testing_verification/BUILD.bazel
@@ -31,8 +31,12 @@ rust_binary(
 
 system_test_nns(
     name = "spec_compliance_application_subnet_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
-    tags = ["cpu:4"],
+    tags = [
+        "cpu:4",
+        "long_test",  # since it takes longer than 5 minutes.
+    ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = BOUNDARY_NODE_GUESTOS_RUNTIME_DEPS + GUESTOS_RUNTIME_DEPS + UNIVERSAL_VM_RUNTIME_DEPS + CANISTER_HTTP_RUNTIME_DEPS + IC_HS_RUNTIME_DEPS + [
         "//ic-os/components:networking/dev-certs/canister_http_test_ca.cert",
@@ -48,8 +52,12 @@ system_test_nns(
 
 system_test_nns(
     name = "spec_compliance_system_subnet_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
-    tags = ["cpu:4"],
+    tags = [
+        "cpu:4",
+        "long_test",
+    ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = BOUNDARY_NODE_GUESTOS_RUNTIME_DEPS + GUESTOS_RUNTIME_DEPS + UNIVERSAL_VM_RUNTIME_DEPS + CANISTER_HTTP_RUNTIME_DEPS + IC_HS_RUNTIME_DEPS + [
         "//ic-os/components:networking/dev-certs/canister_http_test_ca.cert",
@@ -65,8 +73,12 @@ system_test_nns(
 
 system_test_nns(
     name = "spec_compliance_group_01_application_subnet_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
-    tags = ["cpu:4"],
+    tags = [
+        "cpu:4",
+        "long_test",  # since it takes longer than 5 minutes.
+    ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = BOUNDARY_NODE_GUESTOS_RUNTIME_DEPS + GUESTOS_RUNTIME_DEPS + UNIVERSAL_VM_RUNTIME_DEPS + CANISTER_HTTP_RUNTIME_DEPS + IC_HS_RUNTIME_DEPS + [
         "//ic-os/components:networking/dev-certs/canister_http_test_ca.cert",
@@ -82,8 +94,12 @@ system_test_nns(
 
 system_test_nns(
     name = "spec_compliance_group_01_system_subnet_test",
+    extra_head_nns_tags = [],  # don't run the head_nns variant on nightly since it aleady runs on long_test.
     flaky = True,
-    tags = ["cpu:4"],
+    tags = [
+        "cpu:4",
+        "long_test",
+    ],
     target_compatible_with = ["@platforms//os:linux"],  # requires libssh that does not build on Mac OS
     runtime_deps = BOUNDARY_NODE_GUESTOS_RUNTIME_DEPS + GUESTOS_RUNTIME_DEPS + UNIVERSAL_VM_RUNTIME_DEPS + CANISTER_HTTP_RUNTIME_DEPS + IC_HS_RUNTIME_DEPS + [
         "//ic-os/components:networking/dev-certs/canister_http_test_ca.cert",