diff --git a/libervia/backend/core/constants.py b/libervia/backend/core/constants.py
index 55ff1b94..80f2bd7e 100644
--- a/libervia/backend/core/constants.py
+++ b/libervia/backend/core/constants.py
@@ -18,6 +18,7 @@
 
 import os
 from pathlib import Path
+import tempfile
 from typing import Final
 
 from libervia import backend
@@ -52,17 +53,54 @@ class Const:
     APP_RELEASE_NAME = "La Ruche"
     APP_URL = "https://libervia.org"
 
+    ## Isolation ##
+    isolation_name = os.environ.get("LIBERVIA_ISOLATION")
+
+    if isolation_name:
+        # Validate isolation name: only allow [A-Za-z0-9_-] to prevent path traversal and
+        # other issues.
+        if not isolation_name.replace("-", "").replace("_", "").isalnum():
+            raise ValueError(
+                f"Invalid LIBERVIA_ISOLATION name {isolation_name!r}, "
+                f"must only contain [A-Za-z0-9_-]"
+            )
+        isolation_mode = os.environ.get("LIBERVIA_ISOLATION_MODE", "normal").lower()
+        match isolation_mode:
+            case "tmp":
+                ISOLATED_LOCAL_DIR = (
+                    Path(tempfile.gettempdir()) / f"libervia_isolated_{isolation_name}"
+                )
+                ISOLATED_RUNTIME_DIR = (
+                    Path(tempfile.gettempdir())
+                    / f"libervia_isolated_{isolation_name}_run"
+                )
+                ISOLATED_CONFIG_DIR = (
+                    xdg_config_home / APP_NAME_FILE / "isolated" / isolation_name
+                )
+            case "normal" | "full":
+                _dir_suffix = Path("isolated") / isolation_name
+                ISOLATED_LOCAL_DIR = xdg_data_home / APP_NAME_FILE / _dir_suffix
+                ISOLATED_RUNTIME_DIR = xdg_runtime_dir / APP_NAME_FILE / _dir_suffix
+                ISOLATED_CONFIG_DIR = xdg_config_home / APP_NAME_FILE / _dir_suffix
+            case _:
+                raise ValueError(
+                    f"Invalid LIBERVIA_ISOLATION_MODE {isolation_mode!r}, "
+                    f"must be one of: normal, full, tmp"
+                )
+    else:
+        isolation_mode = None
+        ISOLATED_LOCAL_DIR = None
+        ISOLATED_RUNTIME_DIR = None
+        ISOLATED_CONFIG_DIR = None
+
     ## Configuration ##
+    # Config paths are ordered by priority (lowest first).
+    # Later entries override earlier ones.
     CONFIG_PATHS = [
         # /etc/_ is used for system-related settings (when a value is set by the
         # distribution, or in a Docker image)
         Path("/etc/_"),
         Path("/etc/"),
-        Path.home(),
-        xdg_config_home / APP_NAME_FILE,
-        # We use backend root as last config path, this is useful for per instance
-        # configurations.
-        Path(backend.__file__).parent.parent,
     ]
 
     for d in xdg_config_dirs:
@@ -75,6 +113,9 @@ class Const:
         # to add /app
         CONFIG_PATHS.append(Path("/app/"))
 
+    CONFIG_PATHS.append(xdg_config_home / APP_NAME_FILE)
+    CONFIG_PATHS.append(Path.home())
+
     CONFIG_FILES: list[Path] = []
     for p in CONFIG_PATHS:
         CONFIG_FILES.append(p / f"{APP_NAME_FILE}.toml")
@@ -82,7 +123,16 @@ class Const:
     # In $HOME, the config file can be hidden.
     CONFIG_FILES.append(Path.home() / f".{APP_NAME_FILE}.toml")
 
-    RUNTIME_DIR = xdg_runtime_dir / APP_NAME_FILE
+    if ISOLATED_CONFIG_DIR is not None:
+        isolated_conf = ISOLATED_CONFIG_DIR / f"{APP_NAME_FILE}.toml"
+        if isolation_mode == "normal":
+            CONFIG_FILES.append(isolated_conf)
+        else:
+            CONFIG_FILES = [isolated_conf]
+
+    RUNTIME_DIR = (
+        ISOLATED_RUNTIME_DIR if ISOLATED_RUNTIME_DIR else xdg_runtime_dir / APP_NAME_FILE
+    )
 
     ## Runtime ##
     PLUGIN_EXT = "py"
diff --git a/libervia/backend/core/launcher.py b/libervia/backend/core/launcher.py
index 6192c139..4559ced8 100644
--- a/libervia/backend/core/launcher.py
+++ b/libervia/backend/core/launcher.py
@@ -21,6 +21,8 @@
 import sys
 import os
 import argparse
+import shutil
+import tempfile
 from argparse import _SubParsersAction
 from pathlib import Path
 
@@ -72,6 +74,25 @@ class Launcher:
         except Exception as e:
             print(rf"/!\ Can't read main config! {e}")
             sys.exit(1)
+        if C.isolation_mode == "tmp":
+            self.clean_tmp_dir()
+        if C.isolation_mode is not None:
+            print(
+                f"Isolation mode '{C.isolation_mode}' active "
+                f"(instance: {C.isolation_name}, "
+                f"config: {C.ISOLATED_CONFIG_DIR})"
+            )
+
+    def clean_tmp_dir(self) -> None:
+        """Remove temporary isolation directory on startup."""
+        tmp_path = C.ISOLATED_LOCAL_DIR
+        if tmp_path is None:
+            return
+        # We want to be sure that we delete a temporary directory, and not accidentally
+        # another local directory.
+        if str(tmp_path).startswith(tempfile.gettempdir()):
+            shutil.rmtree(tmp_path, ignore_errors=True)
+            print(f"Cleaned temp isolation directory: {tmp_path}")
 
     def cmd_no_subparser(self, args):
         """Command launched by default"""
diff --git a/libervia/backend/tools/config.py b/libervia/backend/tools/config.py
index 7f87b1b2..6883c1f2 100644
--- a/libervia/backend/tools/config.py
+++ b/libervia/backend/tools/config.py
@@ -222,6 +222,18 @@ class DBusBridgeSettings(ConfigOptions):
         default="org.libervia.Libervia", description="Interface prefix"
     )
 
+    @model_validator(mode="after")
+    def force_isolated_int_prefix(self) -> Self:
+        """Append isolation name to D-Bus service prefix to avoid conflicts."""
+        if C.isolation_name is not None:
+            # The isolation name is already restricted, so we only need to handle D-Bus
+            # specific rules.
+            sanitized = C.isolation_name.replace("-", "_")
+            if sanitized[0].isdigit():
+                sanitized = f"_{sanitized}"
+            self.int_prefix = f"{self.int_prefix}.isolated.{sanitized}"
+        return self
+
 
 class AutoBridgeSettings(ConfigOptions):
     """Automatic Bridge.
@@ -403,6 +415,13 @@ class CommonSettings(ConfigOptions):
         description="JID of the entity used for group chat searches.",
     )
 
+    @model_validator(mode="after")
+    def force_isolated_local_dir(self) -> Self:
+        # In isolated mode, we force local_dir to avoid issues with parent configs.
+        if C.ISOLATED_LOCAL_DIR is not None:
+            self.local_dir = C.ISOLATED_LOCAL_DIR
+        return self
+
 
 class Settings(BaseSettings):
     model_config = SettingsConfigDict(