diff --git a/Cargo.lock b/Cargo.lock
index ff6ee7d53c..c49a8133f3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1134,6 +1134,19 @@ dependencies = [
  "syn 2.0.22",
 ]
 
+[[package]]
+name = "dashmap"
+version = "5.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6943ae99c34386c84a470c499d3414f66502a41340aa895406e0d2e4a207b91d"
+dependencies = [
+ "cfg-if",
+ "hashbrown 0.14.0",
+ "lock_api",
+ "once_cell",
+ "parking_lot_core 0.9.8",
+]
+
 [[package]]
 name = "data-encoding"
 version = "2.4.0"
@@ -3854,6 +3867,31 @@ dependencies = [
  "syn 2.0.22",
 ]
 
+[[package]]
+name = "serial_test"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0e56dd856803e253c8f298af3f4d7eb0ae5e23a737252cd90bb4f3b435033b2d"
+dependencies = [
+ "dashmap",
+ "futures",
+ "lazy_static",
+ "log",
+ "parking_lot 0.12.1",
+ "serial_test_derive",
+]
+
+[[package]]
+name = "serial_test_derive"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "91d129178576168c589c9ec973feedf7d3126c01ac2bf08795109aa35b69fb8f"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.22",
+]
+
 [[package]]
 name = "sha1"
 version = "0.10.5"
@@ -4337,6 +4375,7 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "serde_json",
+ "serial_test",
  "spacetimedb-client-api",
  "spacetimedb-core",
  "spacetimedb-lib",
diff --git a/Cargo.toml b/Cargo.toml
index 45270e5a94..215be8b76b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -125,6 +125,7 @@ serde = "1.0.136"
 serde_json = { version = "1.0.87", features = ["raw_value"] }
 serde_path_to_error = "0.1.9"
 serde_with = { version = "2.2.0", features = ["base64", "hex"] }
+serial_test = "2.0.0"
 sha1 = "0.10.1"
 sha3 = "0.10.0"
 slab = "0.4.7"
diff --git a/crates/core/src/config.rs b/crates/core/src/config.rs
new file mode 100644
index 0000000000..fb95523ee7
--- /dev/null
+++ b/crates/core/src/config.rs
@@ -0,0 +1,154 @@
+use std::env::temp_dir;
+use std::path::{Path, PathBuf};
+
+#[cfg(not(any(target_os = "macos", target_os = "windows")))]
+mod paths {
+    use super::*;
+
+    /// The default path for the database files.
+    pub(super) fn db_path() -> PathBuf {
+        PathBuf::from("/stdb")
+    }
+
+    /// The default path for the database logs.
+    pub(super) fn logs_path() -> PathBuf {
+        PathBuf::from("/var/log")
+    }
+
+    /// The default path for the database config files.
+    pub(super) fn config_path() -> PathBuf {
+        PathBuf::from("/etc/spacetimedb/")
+    }
+}
+
+#[cfg(target_os = "macos")]
+mod paths {
+    use super::*;
+
+    /// The default path for the database files.
+    pub(super) fn db_path() -> PathBuf {
+        PathBuf::from("/usr/local/var/stdb")
+    }
+
+    /// The default path for the database logs.
+    pub(super) fn logs_path() -> PathBuf {
+        PathBuf::from("/var/log")
+    }
+
+    /// The default path for the database config files.
+    pub(super) fn config_path() -> PathBuf {
+        PathBuf::from("/etc/spacetimedb/")
+    }
+}
+
+#[cfg(target_os = "windows")]
+mod paths {
+    use super::*;
+
+    /// The default path for the database files.
+    pub(super) fn db_path() -> PathBuf {
+        dirs::data_dir()
+            .map(|x| x.join("stdb"))
+            .expect("failed to read the windows `data directory`")
+    }
+
+    /// The default path for the database logs.
+    pub(super) fn logs_path() -> PathBuf {
+        db_path().join("log")
+    }
+
+    /// The default path for the database config files.
+    pub(super) fn config_path() -> PathBuf {
+        dirs::config_dir()
+            .map(|x| x.join("stdb"))
+            .expect("Fail to read the windows `config directory`")
+    }
+}
+
+/// Returns the default path for the database in the `OS` temporary directory.
+pub fn stdb_path_temp() -> PathBuf {
+    temp_dir().join("stdb")
+}
+
+/// Types specifying where to find various files needed by spacetimedb.
+pub trait SpacetimeDbFiles {
+    /// The path for the database files.
+    fn db_path(&self) -> PathBuf;
+
+    /// The path for the database logs.
+    fn logs(&self) -> PathBuf;
+
+    /// The path for the database config files.
+    fn config(&self) -> PathBuf;
+
+    /// The path of the database config file `log.conf` for logs.
+    fn log_config(&self) -> PathBuf {
+        self.config().join("log.conf")
+    }
+
+    /// The path of the private key file `id_ecdsa`.
+    fn private_key(&self) -> PathBuf {
+        self.config().join("id_ecdsa")
+    }
+
+    /// The path of the public key file `id_ecdsa.pub`.
+    fn public_key(&self) -> PathBuf {
+        self.config().join("id_ecdsa.pub")
+    }
+}
+
+/// The location of paths for the database in a local OR temp folder.
+pub struct FilesLocal {
+    dir: PathBuf,
+}
+
+impl FilesLocal {
+    /// Create a new [FilesLocal], appending `name` to the `temp` folder returned by [stdb_path_temp].
+    pub fn temp(name: &str) -> Self {
+        assert!(!name.is_empty(), "`name` should be filled");
+
+        Self {
+            dir: stdb_path_temp().join(name),
+        }
+    }
+
+    /// Create a new [FilesLocal] that is in a hidden `path + .spacetime` folder.
+    pub fn hidden<P: AsRef<Path>>(path: P) -> Self {
+        Self {
+            dir: path.as_ref().join(".spacetime"),
+        }
+    }
+}
+
+impl SpacetimeDbFiles for FilesLocal {
+    fn db_path(&self) -> PathBuf {
+        self.dir.clone()
+    }
+
+    fn logs(&self) -> PathBuf {
+        self.db_path().join("logs")
+    }
+
+    fn config(&self) -> PathBuf {
+        self.db_path().join("conf")
+    }
+}
+
+/// The global location of paths for the database.
+///
+/// NOTE: This location varies by OS.
+pub struct FilesGlobal;
+
+impl SpacetimeDbFiles for FilesGlobal {
+    fn db_path(&self) -> PathBuf {
+        paths::db_path()
+    }
+
+    fn logs(&self) -> PathBuf {
+        paths::logs_path()
+    }
+
+    fn config(&self) -> PathBuf {
+        paths::config_path()
+    }
+}
diff --git a/crates/core/src/database_logger.rs b/crates/core/src/database_logger.rs
index f03b4f31f6..d42baff709 100644
--- a/crates/core/src/database_logger.rs
+++ b/crates/core/src/database_logger.rs
@@ -177,7 +177,7 @@ impl DatabaseLogger {
         let filepath = root.join("0.log");
 
         // TODO: Read backwards from the end of the file to only read in the latest lines
-        let text = tokio::fs::read_to_string(&filepath).await.expect("reading file");
+        let text = tokio::fs::read_to_string(&filepath).await.expect("reading log file");
 
         let Some(num_lines) = num_lines else { return text };
 
diff --git a/crates/core/src/lib.rs b/crates/core/src/lib.rs
index a2e5eaa882..ac44494523 100644
--- a/crates/core/src/lib.rs
+++ b/crates/core/src/lib.rs
@@ -48,6 +48,7 @@ pub mod protobuf {
     pub use spacetimedb_client_api_messages::*;
 }
 pub mod client;
+pub mod config;
 pub mod control_db;
 pub mod database_instance_context;
 pub mod database_instance_context_controller;
diff --git a/crates/standalone/src/subcommands/start.rs b/crates/standalone/src/subcommands/start.rs
index 0ce7fec277..6c9d2694ae 100644
--- a/crates/standalone/src/subcommands/start.rs
+++ b/crates/standalone/src/subcommands/start.rs
@@ -3,6 +3,7 @@ use crate::util::{create_dir_or_err, create_file_with_contents};
 use crate::StandaloneEnv;
 use clap::ArgAction::SetTrue;
 use clap::{Arg, ArgMatches};
+use spacetimedb::config::{FilesGlobal, FilesLocal, SpacetimeDbFiles};
 use spacetimedb::db::{db_metrics, Storage};
 use spacetimedb::{startup, worker_metrics};
 use std::net::TcpListener;
@@ -85,20 +86,22 @@ pub fn cli(mode: ProgramMode) -> clap::Command {
     // The standalone mode instead uses global directories.
     match mode {
         ProgramMode::CLI => {
-            log_conf_path_arg = log_conf_path_arg.default_value(format!("{}/.spacetime/log.conf", default_root));
-            log_dir_path_arg = log_dir_path_arg.default_value(format!("{}/.spacetime", default_root));
-            database_path_arg = database_path_arg.default_value(format!("{}/.spacetime/stdb", default_root));
-            jwt_pub_key_path_arg =
-                jwt_pub_key_path_arg.default_value(format!("{}/.spacetime/id_ecdsa.pub", default_root));
-            jwt_priv_key_path_arg =
-                jwt_priv_key_path_arg.default_value(format!("{}/.spacetime/id_ecdsa", default_root));
+            let paths = FilesLocal::hidden(default_root);
+
+            log_conf_path_arg = log_conf_path_arg.default_value(paths.log_config().into_os_string());
+            log_dir_path_arg = log_dir_path_arg.default_value(paths.logs().into_os_string());
+            database_path_arg = database_path_arg.default_value(paths.db_path().into_os_string());
+            jwt_pub_key_path_arg = jwt_pub_key_path_arg.default_value(paths.public_key().into_os_string());
+            jwt_priv_key_path_arg = jwt_priv_key_path_arg.default_value(paths.private_key().into_os_string());
         }
         ProgramMode::Standalone => {
-            log_conf_path_arg = log_conf_path_arg.default_value("/etc/spacetimedb/log.conf");
-            log_dir_path_arg = log_dir_path_arg.default_value("/var/log");
-            database_path_arg = database_path_arg.default_value("/stdb");
-            jwt_pub_key_path_arg = jwt_pub_key_path_arg.default_value("/etc/spacetimedb/id_ecdsa.pub");
-            jwt_priv_key_path_arg = jwt_priv_key_path_arg.default_value("/etc/spacetimedb/id_ecdsa");
+            let paths = FilesGlobal;
+
+            log_conf_path_arg = log_conf_path_arg.default_value(paths.log_config().into_os_string());
+            log_dir_path_arg = log_dir_path_arg.default_value(paths.logs().into_os_string());
+            database_path_arg = database_path_arg.default_value(paths.db_path().into_os_string());
+            jwt_pub_key_path_arg = jwt_pub_key_path_arg.default_value(paths.public_key().into_os_string());
+            jwt_priv_key_path_arg = jwt_priv_key_path_arg.default_value(paths.private_key().into_os_string());
         }
     }
 
diff --git a/crates/testing/Cargo.toml b/crates/testing/Cargo.toml
index cdd9b59a5b..09d4744349 100644
--- a/crates/testing/Cargo.toml
+++ b/crates/testing/Cargo.toml
@@ -13,3 +13,6 @@ anyhow.workspace = true
 serde_json.workspace = true
 tokio.workspace = true
 wasmbin.workspace = true
+
+[dev-dependencies]
+serial_test.workspace = true
diff --git a/crates/testing/src/lib.rs b/crates/testing/src/lib.rs
index 53a18e18ec..50842351b2 100644
--- a/crates/testing/src/lib.rs
+++ b/crates/testing/src/lib.rs
@@ -1,18 +1,18 @@
+use spacetimedb::config::{FilesLocal, SpacetimeDbFiles};
 use std::env;
-use std::path::{Path, PathBuf};
 
 pub mod modules;
 
-pub fn set_key_env_vars() {
+pub fn set_key_env_vars(paths: &FilesLocal) {
     let set_if_not_exist = |var, path| {
         if env::var_os(var).is_none() {
-            env::set_var(var, Path::new(env!("CARGO_MANIFEST_DIR")).join("../..").join(path));
+            env::set_var(var, path);
         }
     };
 
-    set_if_not_exist("STDB_PATH", PathBuf::from("/stdb"));
-    set_if_not_exist("SPACETIMEDB_LOGS_PATH", PathBuf::from("/var/log"));
-    set_if_not_exist("SPACETIMEDB_LOG_CONFIG", PathBuf::from("/stdb/log.conf"));
-    set_if_not_exist("SPACETIMEDB_JWT_PUB_KEY", PathBuf::from("/stdb/id_ecdsa.pub"));
-    set_if_not_exist("SPACETIMEDB_JWT_PRIV_KEY", PathBuf::from("/stdb/id_ecdsa"));
+    set_if_not_exist("STDB_PATH", paths.db_path());
+    set_if_not_exist("SPACETIMEDB_LOGS_PATH", paths.logs());
+    set_if_not_exist("SPACETIMEDB_LOG_CONFIG", paths.log_config());
+    set_if_not_exist("SPACETIMEDB_JWT_PUB_KEY", paths.public_key());
+    set_if_not_exist("SPACETIMEDB_JWT_PRIV_KEY", paths.private_key());
 }
diff --git a/crates/testing/src/modules.rs b/crates/testing/src/modules.rs
index b1bf914c27..9c248d5261 100644
--- a/crates/testing/src/modules.rs
+++ b/crates/testing/src/modules.rs
@@ -10,6 +10,7 @@ use spacetimedb::database_logger::DatabaseLogger;
 use spacetimedb::db::Storage;
 use spacetimedb::hash::hash_bytes;
 
+use spacetimedb::config::{FilesLocal, SpacetimeDbFiles};
 use spacetimedb::messages::control_db::HostType;
 use spacetimedb_client_api::{ControlCtx, ControlStateDelegate, WorkerCtx};
 use spacetimedb_standalone::StandaloneEnv;
@@ -129,7 +130,12 @@ pub async fn load_module(name: &str) -> ModuleHandle {
     // exercise functionality like restarting the database.
     let storage = Storage::Disk;
 
-    crate::set_key_env_vars();
+    let paths = FilesLocal::temp(name);
+    // The database created in the `temp` folder can't be randomized,
+    // so it persists after running the test.
+    std::fs::remove_dir(paths.db_path()).ok();
+
+    crate::set_key_env_vars(&paths);
     let env = spacetimedb_standalone::StandaloneEnv::init(storage).await.unwrap();
     let identity = env.control_db().alloc_spacetime_identity().await.unwrap();
     let address = env.control_db().alloc_spacetime_address().await.unwrap();
diff --git a/crates/testing/tests/standalone_integration_test.rs b/crates/testing/tests/standalone_integration_test.rs
index abf3beace2..8232ca2598 100644
--- a/crates/testing/tests/standalone_integration_test.rs
+++ b/crates/testing/tests/standalone_integration_test.rs
@@ -1,7 +1,12 @@
 use serde_json::Value;
+use serial_test::serial;
 use spacetimedb_testing::modules::{compile, with_module_async};
 
+// The tests MUST be run in sequence because they read the OS environment
+// and can cause a race when run in parallel.
+
 #[test]
+#[serial]
 fn test_calling_a_reducer() {
     compile("spacetimedb-quickstart");
     with_module_async("spacetimedb-quickstart", |module| async move {
@@ -23,6 +28,7 @@ fn test_calling_a_reducer() {
 }
 
 #[test]
+#[serial]
 fn test_calling_a_reducer_with_private_table() {
     compile("rust-wasm-test");
     with_module_async("rust-wasm-test", |module| async move {
diff --git a/run_standalone.sh b/run_standalone_temp.sh
similarity index 86%
rename from run_standalone.sh
rename to run_standalone_temp.sh
index 719b698af4..fc681ab53a 100755
--- a/run_standalone.sh
+++ b/run_standalone_temp.sh
@@ -1,4 +1,5 @@
 #!/bin/bash
+# Run a ephemeral database inside a `temp` folder
 set -euo pipefail
 
 SRC_TREE="$(dirname "$0")"
@@ -15,6 +16,13 @@ cargo build -p spacetimedb-standalone
 export STDB_PATH="${STDB_PATH:-$(mktemp -d)}"
 mkdir -p "$STDB_PATH/logs"
 
+function cleanup {
+  echo "Removing ${STDB_PATH}"
+  rm  -rf "$STDB_PATH"
+}
+
+trap cleanup EXIT
+
 cp crates/standalone/log.conf "$STDB_PATH/log.conf"
 # -i differs between GNU and BSD sed, so use a temp file
 sed 's/spacetimedb=debug/spacetimedb=trace/g' "$STDB_PATH/log.conf" > "$STDB_PATH/log.conf.tmp" && \