diff --git a/casket-backend/src/files/list.rs b/casket-backend/src/files/list.rs
index 5833f2f..f480ddd 100644
--- a/casket-backend/src/files/list.rs
+++ b/casket-backend/src/files/list.rs
@@ -12,6 +12,7 @@ use std::path::PathBuf;
 use tokio::fs::{read_dir, DirEntry};
 use tracing::{debug, error};
 
+/// Handler to query a file tree. The query parameters can be used to control what is is queried.
 #[debug_handler]
 pub async fn query_file_tree(
     State(state): State<AppState>,
@@ -20,56 +21,86 @@ pub async fn query_file_tree(
 ) -> Result<Json<PathElements>, ProblemDetails> {
     let path = build_system_path(&state.config.files.directory, &user_id, &query.path)?;
     debug!("Loading path: {:?}", path);
-    Ok(PathElements::new(load_directory(path, query.nesting).await?).into())
-}
-
-async fn load_directory(path: PathBuf, nesting: u32) -> Result<Vec<PathElement>, ProblemDetails> {
-    match read_dir(path).await {
-        Err(error) => Err(map_io_error(error)),
-        Ok(mut value) => {
-            let mut result = vec![];
-            while let Some(next) = value.next_entry().await.map_err(map_io_error)? {
-                result.push(PathElement::from(next, nesting).await?);
-            }
-            Ok(result)
-        }
-    }
-}
-
-fn map_io_error(error: Error) -> ProblemDetails {
-    match error.kind() {
-        std::io::ErrorKind::NotFound => ProblemDetails::from_status_code(StatusCode::NOT_FOUND),
-        _ => to_internal_error(error),
-    }
+    PathElements::load(path, query.nesting)
+        .await
+        .map(Json::from)
 }
 
+/// Query to control how a file tree is queried.
 #[derive(Deserialize)]
 pub struct FileQuery {
+    /// Path which is used as base path to query the tree.
     path: PathBuf,
     #[serde(default = "u32::min_value")]
+    /// The amount of layers the tree should be loaded for. Can be used to cache a certain amount
+    /// of levels for a better UX when browsing the data.
     nesting: u32,
 }
 
+/// Represents the root of a file tree.
 #[derive(Serialize)]
 pub struct PathElements {
     files: Vec<PathElement>,
 }
 
+/// Represents a node in the file tree.
+#[derive(Serialize)]
+pub struct PathElement {
+    /// The name of the directory or file.
+    name: String,
+    is_dir: bool,
+    /// Empty children means that the node is either a file or an empty directory.
+    /// None means that the children have not been loaded.
+    children: Option<Vec<PathElement>>,
+}
+
 impl PathElements {
     pub fn new(files: Vec<PathElement>) -> Self {
         Self { files }
     }
-}
 
-#[derive(Serialize)]
-pub struct PathElement {
-    name: String,
-    is_dir: bool,
-    children: Option<Vec<PathElement>>,
-}
+    /// Loads a path recursively nested for up to the provided nesting parameter.
+    pub async fn load(path: PathBuf, nesting: u32) -> Result<Self, ProblemDetails> {
+        Self::load_directory(path, nesting).await.map(Self::new)
+    }
 
-impl PathElement {
-    async fn from(value: DirEntry, nesting: u32) -> Result<Self, ProblemDetails> {
+    async fn load_directory(
+        path: PathBuf,
+        nesting: u32,
+    ) -> Result<Vec<PathElement>, ProblemDetails> {
+        match read_dir(path).await {
+            Err(error) => Err(Self::map_io_error(error)),
+            Ok(mut value) => {
+                let mut result = vec![];
+                while let Some(next) = value.next_entry().await.map_err(Self::map_io_error)? {
+                    result.push(Self::load_path_element(next, nesting).await?);
+                }
+                Ok(result)
+            }
+        }
+    }
+
+    async fn load_children(
+        path: PathBuf,
+        nesting: u32,
+        is_dir: bool,
+    ) -> Result<Option<Vec<PathElement>>, ProblemDetails> {
+        if nesting == 0 {
+            Ok(None)
+        } else if !is_dir {
+            Ok(Some(vec![]))
+        } else {
+            Ok(Some(
+                // needs to call pin to support recursion in async contexts.
+                Box::pin(Self::load_directory(path, nesting - 1)).await?,
+            ))
+        }
+    }
+
+    async fn load_path_element(
+        value: DirEntry,
+        nesting: u32,
+    ) -> Result<PathElement, ProblemDetails> {
         let metadata = value.metadata().await.unwrap();
         debug!("File type: {:?}", value.file_type().await.unwrap());
         let is_dir = metadata.is_dir();
@@ -77,11 +108,11 @@ impl PathElement {
             Ok(PathElement {
                 name: value.file_name().into_string().unwrap(),
                 is_dir,
-                children: load_children(value.path(), nesting, is_dir).await?,
+                children: Self::load_children(value.path(), nesting, is_dir).await?,
             })
         } else {
             error!(
-                "File <{:?}> is neither a directory nor a file. ",
+                "File <{:?}> is neither a directory nor a file.",
                 value.file_name()
             );
             Err(
@@ -90,18 +121,11 @@ impl PathElement {
             )
         }
     }
-}
 
-async fn load_children(
-    path: PathBuf,
-    nesting: u32,
-    is_dir: bool,
-) -> Result<Option<Vec<PathElement>>, ProblemDetails> {
-    if nesting == 0 {
-        Ok(None)
-    } else if !is_dir {
-        Ok(Some(vec![]))
-    } else {
-        Ok(Some(Box::pin(load_directory(path, nesting - 1)).await?))
+    fn map_io_error(error: Error) -> ProblemDetails {
+        match error.kind() {
+            std::io::ErrorKind::NotFound => ProblemDetails::from_status_code(StatusCode::NOT_FOUND),
+            _ => to_internal_error(error),
+        }
     }
 }
diff --git a/casket-backend/src/files/upload.rs b/casket-backend/src/files/upload.rs
index c524792..6ec8db6 100644
--- a/casket-backend/src/files/upload.rs
+++ b/casket-backend/src/files/upload.rs
@@ -53,7 +53,7 @@ async fn handle_single_file_upload<'field_lifetime>(
     }
 }
 
-pub async fn save_file(
+async fn save_file(
     path: PathBuf,
     mut content: impl Stream<Item = Result<Bytes, Error>> + Unpin,
 ) -> Result<(), Error> {