diff --git a/backend/src/gc.rs b/backend/src/gc.rs
new file mode 100644
index 0000000..69cdcdf
--- /dev/null
+++ b/backend/src/gc.rs
@@ -0,0 +1,36 @@
+use diesel::prelude::*;
+use diesel_async::RunQueryDsl;
+
+#[tracing::instrument(skip(storage))]
+pub async fn run_gc(storage: &mut dyn crate::storage::DemoStorage) -> Result<(), ()> {
+    let stored_demos = match storage.list_demos().await {
+        Ok(ds) => ds,
+        Err(e) => return Err(()),
+    };
+
+    tracing::info!("Found {} demos in storage", stored_demos.len());
+
+    let mut db_con = crate::db_connection().await;
+
+    let db_res = db_con
+        .build_transaction()
+        .run(move |con| {
+            Box::pin(async move {
+                for demo in stored_demos {
+                    let query = crate::schema::demos::dsl::demos
+                        .filter(crate::schema::demos::dsl::demo_id.eq(&demo)).select(crate::models::Demo::as_select());
+                    
+                    let matching: Vec<crate::models::Demo> = query.load(con).await?;
+
+                    if matching.is_empty() {
+                        tracing::debug!("Should delete old demo {:?}", demo);
+                    }
+                }
+
+                Ok::<(), diesel::result::Error>(())
+            })
+        })
+        .await;
+
+    db_res.map_err(|e| ())
+}
diff --git a/backend/src/lib.rs b/backend/src/lib.rs
index 13a3b1b..432201a 100644
--- a/backend/src/lib.rs
+++ b/backend/src/lib.rs
@@ -8,6 +8,8 @@ pub mod diesel_sessionstore;
 
 pub mod analysis;
 
+mod gc;
+
 pub async fn db_connection() -> diesel_async::AsyncPgConnection {
     use diesel_async::AsyncConnection;
 
@@ -132,3 +134,16 @@ pub async fn run_analysis(storage: Box<dyn crate::storage::DemoStorage>) {
         }
     }
 }
+
+#[tracing::instrument(skip(storage))]
+pub async fn run_garbage_collection(mut storage: Box<dyn crate::storage::DemoStorage>) {
+    loop {
+        tracing::info!("Running Garbage Collection");
+
+        if let Err(e) = gc::run_gc(storage.as_mut()).await {
+            tracing::error!("Running GC {:?}", e);
+        }
+
+        tokio::time::sleep(std::time::Duration::from_secs(15 * 60)).await;
+    }
+}
diff --git a/backend/src/main.rs b/backend/src/main.rs
index 15115cc..5424da7 100644
--- a/backend/src/main.rs
+++ b/backend/src/main.rs
@@ -27,6 +27,9 @@ struct CliArgs {
 
     #[clap(long = "analysis", default_value_t = true)]
     analysis: bool,
+
+    #[clap(long = "gc", default_value_t = true)]
+    garbage_collection: bool,
 }
 
 #[tokio::main(flavor = "multi_thread")]
@@ -93,7 +96,12 @@ async fn main() {
     if args.analysis {
         tracing::info!("Enabled Analysis module");
 
-        component_set.spawn(backend::run_analysis(storage));
+        component_set.spawn(backend::run_analysis(storage.duplicate()));
+    }
+    if args.garbage_collection {
+        tracing::info!("Enabled Garbage-Collection module");
+
+        component_set.spawn(backend::run_garbage_collection(storage));
     }
     tracing::info!("Started modules");
 
diff --git a/backend/src/storage.rs b/backend/src/storage.rs
index 6c72aab..207e4a7 100644
--- a/backend/src/storage.rs
+++ b/backend/src/storage.rs
@@ -21,6 +21,9 @@ pub trait DemoStorage: Send + Sync {
     ) -> futures::future::BoxFuture<'f, Result<crate::analysis::AnalysisData, String>>
     where
         'own: 'f;
+
+    fn list_demos<'own, 'f>(&'own self) -> futures::future::BoxFuture<'f, Result<Vec<String>, String>>
+    where 'own: 'f;
 }
 
 pub struct FileStorage {
@@ -107,6 +110,14 @@ impl DemoStorage for FileStorage {
         }
         .boxed()
     }
+
+    fn list_demos<'own, 'f>(&'own self) -> futures::future::BoxFuture<'f, Result<Vec<String>, String>>
+    where 'own: 'f {
+        async move {
+            // TODO
+            Ok(Vec::new())
+        }.boxed()
+    }
 }
 
 pub struct S3Storage {
@@ -184,4 +195,20 @@ impl DemoStorage for S3Storage {
         }
         .boxed()
     }
+
+    fn list_demos<'own, 'f>(&'own self) -> futures::future::BoxFuture<'f, Result<Vec<String>, String>>
+    where 'own: 'f {
+        async move {
+            let listed = match self.bucket.list("".to_string(), None).await {
+                Ok(l) => l,
+                Err(e) => return Err(format!("{:?}", e)),
+            };
+
+            Ok(listed.into_iter().flat_map(|rs| {
+                rs.contents.into_iter().map(|entry| {
+                    entry.key
+                })
+            }).collect())
+        }.boxed()
+    }
 }