diff --git a/Cargo.lock b/Cargo.lock
index f035e31c..a39587d7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -512,6 +512,7 @@ name = "dora-rs"
 version = "0.1.0"
 dependencies = [
  "env_logger",
+ "envy",
  "eyre",
  "futures",
  "pyo3",
@@ -536,6 +537,15 @@ dependencies = [
  "termcolor",
 ]
 
+[[package]]
+name = "envy"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f47e0157f2cb54f5ae1bd371b30a2ae4311e1c028f575cd4e81de7353215965"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "event-listener"
 version = "2.5.2"
diff --git a/Cargo.toml b/Cargo.toml
index 9c487bbc..fd206673 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -16,3 +16,4 @@ tokio = { version="1.17.0", features=["full"]}
 pyo3 = "0.16.1"
 pyo3-asyncio = { version = "0.16", features = ["tokio-runtime", "attributes"] }
 futures = "0.3.12"
+envy = "0.4.2"
\ No newline at end of file
diff --git a/src/server.rs b/src/server.rs
index 0f469c36..3e857752 100644
--- a/src/server.rs
+++ b/src/server.rs
@@ -1,32 +1,41 @@
 use eyre::{eyre, Context};
-use futures::prelude::*;
+use futures::future::join_all;
+use futures::stream::Next;
+use futures::{join, prelude::*};
 use pyo3::prelude::*;
 use std::collections::hash_map::DefaultHasher;
 use std::collections::{BTreeMap, HashMap};
-use std::env;
 use std::hash::Hash;
 use std::hash::Hasher;
-use std::time::Duration;
+use std::time::{Duration, Instant};
 use tokio::time::timeout;
 use zenoh::config::Config;
 use zenoh::prelude::SplitBuffer;
-static DURATION_MILLIS: u64 = 5;
+static DURATION_MILLIS: u64 = 1;
+use serde::Deserialize;
+
+#[derive(Deserialize, Debug)]
+struct ConfigVariables {
+    subscriptions: Vec<String>,
+    app: String,
+    function: String,
+}
 
 #[pyo3_asyncio::tokio::main]
 pub async fn main() -> PyResult<()> {
     // Subscribe
+    let variables = envy::from_env::<ConfigVariables>().unwrap();
+
     env_logger::init();
     let config = Config::default();
     let session = zenoh::open(config).await.unwrap();
-    let subscriptions = env::var("SRC_LABELS")
-        .wrap_err("Env variable not set")
-        .unwrap();
-    let subscriptions = subscriptions.split(":");
 
+    // Create a hashmap of all subscriptions.
     let mut subscribers = HashMap::new();
+    let subs = variables.subscriptions.clone();
 
-    for subscription in subscriptions {
-        subscribers.insert(subscription, session
+    for subscription in &subs {
+        subscribers.insert(subscription.clone(), session
             .subscribe(subscription)
             .await
             .map_err(|err| {
@@ -35,37 +44,47 @@ pub async fn main() -> PyResult<()> {
             .unwrap());
     }
 
+    // Store the latest value of all subscription as well as the output of the function. hash the state to easily check if the state has changed.
     let mut states = BTreeMap::new();
     let mut hasher = DefaultHasher::new();
     states.hash(&mut hasher);
     let mut state_hash = hasher.finish();
 
-    let identity = initialize("app".to_string(), "return_1".to_string()).unwrap();
+    let py_function = initialize(variables.app, variables.function).unwrap();
     let dur = Duration::from_millis(DURATION_MILLIS);
+    let mut futures_put = vec![];
 
     loop {
-        for (subscription, subscriber) in subscribers.iter_mut() {
-            let result = timeout(dur, subscriber.next()).await;
+        let now = Instant::now();
+        let mut futures = vec![];
+        for (_, v) in subscribers.iter_mut() {
+            futures.push(timeout(dur, v.next()));
+        }
+
+        let results = join_all(futures).await;
+
+        for (result, subscription) in results.into_iter().zip(&subs) {
             if let Ok(Some(data)) = result {
                 let value = data.value.payload;
                 let binary = value.contiguous();
-                states.insert(subscription.clone(), binary.to_vec());
+                states.insert(
+                    subscription.clone().to_string(),
+                    String::from_utf8(binary.to_vec()).unwrap(),
+                );
             }
         }
 
         let mut hasher = DefaultHasher::new();
         states.hash(&mut hasher);
-
-        if state_hash == hasher.finish() {
+        let new_hash = hasher.finish();
+        if state_hash == new_hash {
             continue;
-        } else {
-            state_hash = hasher.finish();
         }
 
         let result = Python::with_gil(|py| {
             let args = (states.clone().into_py(py),);
             pyo3_asyncio::tokio::into_future(
-                identity
+                py_function
                     .call(py, args, None)
                     .wrap_err("The Python function call did not succeed.")
                     .unwrap()
@@ -81,15 +100,16 @@ pub async fn main() -> PyResult<()> {
         let outputs: HashMap<String, String> = Python::with_gil(|py| result.extract(py))
             .wrap_err("Could not retrieve the python result.")
             .unwrap();
+
         for (key, value) in outputs {
-            session
-                .put(key, value)
-                .await
-                .map_err(|err| {
-                    eyre!("Could not put the output within the chosen key expression topic. Error: {err}")
-                })
-                .unwrap();
+            states.insert(key.clone(), value.clone());
+            futures_put.push(timeout(dur, session.put(key, value)));
         }
+
+        let mut hasher = DefaultHasher::new();
+        states.hash(&mut hasher);
+        state_hash = hasher.finish();
+        println!("loop {:#?}", now.elapsed());
     }
 }