diff --git a/vm/src/app_ui/mod.rs b/vm/src/app_ui/mod.rs
new file mode 100644
index 0000000..915a9fa
--- /dev/null
+++ b/vm/src/app_ui/mod.rs
@@ -0,0 +1 @@
+pub mod menu;
\ No newline at end of file
diff --git a/vm/src/handlers/lib/mod.rs b/vm/src/handlers/lib/mod.rs
new file mode 100644
index 0000000..9b969cf
--- /dev/null
+++ b/vm/src/handlers/lib/mod.rs
@@ -0,0 +1 @@
+pub mod outsourced_mem;
\ No newline at end of file
diff --git a/vm/src/handlers/lib/outsourced_mem.rs b/vm/src/handlers/lib/outsourced_mem.rs
new file mode 100644
index 0000000..64fc46f
--- /dev/null
+++ b/vm/src/handlers/lib/outsourced_mem.rs
@@ -0,0 +1,108 @@
+use core::cell::RefCell;
+
+use alloc::rc::Rc;
+use common::vm::{Page, PagedMemory};
+use ledger_device_sdk::io;
+
+use common::constants::PAGE_SIZE;
+use common::client_commands::ClientCommandCode;
+
+use crate::{AppSW, Instruction};
+
+
+// TODO: temporary implementation that stores a single page, and without page integrity checks
+pub struct OutsourcedMemory<'c> {
+    comm: Rc<RefCell<&'c mut io::Comm>>,
+    idx: Option<u32>,
+    page: Page,
+    is_readonly: bool
+}
+
+impl<'c> OutsourcedMemory<'c> {
+    pub fn new(comm: Rc<RefCell<&'c mut io::Comm>>, is_readonly: bool) -> Self {
+        Self {
+            comm,
+            idx: None,
+            page: Page { data: [0; PAGE_SIZE] },
+            is_readonly
+        }
+    }
+
+    fn commit_page(&mut self) -> Result<(), &'static str> {
+        let Some(idx) = self.idx else {
+            panic!("No page to commit");
+        };
+
+        let mut comm = self.comm.borrow_mut();
+
+        // First message: communicate the page to commit
+        // TODO: should add a byte to identify in which segment does the page belong
+        comm.append(&[ClientCommandCode::CommitPage as u8]);
+        comm.append(&idx.to_be_bytes());
+        comm.reply(AppSW::InterruptedExecution);
+
+        let Instruction::Continue(p1, p2) = comm.next_command() else {
+            return Err("INS not supported"); // expected "Continue"
+        };
+
+        if (p1, p2) != (0, 0) {
+            return Err("Wrong P1/P2");
+        }
+
+        // Second message  message: communicate the page content
+        comm.append(&[ClientCommandCode::CommitPageContent as u8]);
+        comm.append(&self.page.data);
+
+        let Instruction::Continue(p1, p2) = comm.next_command() else {
+            return Err("INS not supported"); // expected "Continue"
+        };
+
+        if (p1, p2) != (0, 0) {
+            return Err("Wrong P1/P2");
+        }
+
+        Ok(())
+    }
+}
+
+impl<'c> PagedMemory for OutsourcedMemory<'c> {
+    type PageRef<'a> = &'a mut Page where Self: 'a;
+
+    fn get_page<'a>(&'a mut self, page_index: u32) -> Result<Self::PageRef<'a>, &'static str> {
+        if let Some(idx) = &mut self.idx {
+            if *idx == page_index {
+                return Ok(&mut self.page);
+            } else {
+                if !self.is_readonly {
+                    self.commit_page()?;
+                }
+            }
+        }
+
+        let mut comm = self.comm.borrow_mut();
+        comm.append(&[ClientCommandCode::GetPage as u8]);
+        comm.append(&page_index.to_be_bytes());
+        comm.reply(AppSW::InterruptedExecution);
+
+        let Instruction::Continue(p1, p2) = comm.next_command() else {
+            return Err("INS not supported"); // expected "Continue"
+        };
+
+        if p2 != 0 {
+            return Err("Wrong P2");
+        }
+
+        let fetched_data = comm.get_data().map_err(|_| "Wrong APDU length")?;
+        if fetched_data.len() != PAGE_SIZE - 1 {
+            return Err("Wrong APDU length");
+        }
+        // overwrite page content
+        self.page.data[0..PAGE_SIZE - 1].copy_from_slice(fetched_data);
+        self.page.data[PAGE_SIZE - 1] = p1;
+
+        // update index
+        self.idx = Some(page_index);
+
+        Ok(&mut self.page)
+    }
+}
diff --git a/vm/src/handlers/mod.rs b/vm/src/handlers/mod.rs
new file mode 100644
index 0000000..3653295
--- /dev/null
+++ b/vm/src/handlers/mod.rs
@@ -0,0 +1,5 @@
+pub mod get_version;
+pub mod register_vapp;
+pub mod start_vapp;
+
+mod lib;
\ No newline at end of file
diff --git a/vm/src/handlers/start_vapp.rs b/vm/src/handlers/start_vapp.rs
index 6e1973f..39631db 100644
--- a/vm/src/handlers/start_vapp.rs
+++ b/vm/src/handlers/start_vapp.rs
@@ -1,112 +1,14 @@
 
 use core::cell::RefCell;
 
-use common::vm::{Cpu, MemorySegment, Page, PagedMemory};
-use crate::{println, AppSW, Instruction};
-
 use alloc::rc::Rc;
 use ledger_device_sdk::io;
 
 use common::manifest::Manifest;
-use common::constants::PAGE_SIZE;
-use common::client_commands::ClientCommandCode;
-
-// TODO: temporary implementation that stores a single page, and without page integrity checks
-struct OutsourcedMemory<'c> {
-    comm: Rc<RefCell<&'c mut io::Comm>>,
-    idx: Option<u32>,
-    page: Page,
-    is_readonly: bool
-}
-
-impl<'c> OutsourcedMemory<'c> {
-    fn new(comm: Rc<RefCell<&'c mut io::Comm>>, is_readonly: bool) -> Self {
-        Self {
-            comm,
-            idx: None,
-            page: Page { data: [0; PAGE_SIZE] },
-            is_readonly
-        }
-    }
-
-    fn commit_page(&mut self) -> Result<(), &'static str> {
-        let Some(idx) = self.idx else {
-            panic!("No page to commit");
-        };
-
-        let mut comm = self.comm.borrow_mut();
-
-        // First message: communicate the page to commit
-        // TODO: should add a byte to identify in which segment does the page belong
-        comm.append(&[ClientCommandCode::CommitPage as u8]);
-        comm.append(&idx.to_be_bytes());
-        comm.reply(AppSW::InterruptedExecution);
-
-        let Instruction::Continue(p1, p2) = comm.next_command() else {
-            return Err("INS not supported"); // expected "Continue"
-        };
-
-        if (p1, p2) != (0, 0) {
-            return Err("Wrong P1/P2");
-        }
-
-        // Second message  message: communicate the page content
-        comm.append(&[ClientCommandCode::CommitPageContent as u8]);
-        comm.append(&self.page.data);
+use common::vm::{Cpu, MemorySegment};
 
-        let Instruction::Continue(p1, p2) = comm.next_command() else {
-            return Err("INS not supported"); // expected "Continue"
-        };
-
-        if (p1, p2) != (0, 0) {
-            return Err("Wrong P1/P2");
-        }
-
-        Ok(())
-    }
-}
-
-impl<'c> PagedMemory for OutsourcedMemory<'c> {
-    type PageRef<'a> = &'a mut Page where Self: 'a;
-
-    fn get_page<'a>(&'a mut self, page_index: u32) -> Result<Self::PageRef<'a>, &'static str> {
-        if let Some(idx) = &mut self.idx {
-            if *idx == page_index {
-                return Ok(&mut self.page);
-            } else {
-                if !self.is_readonly {
-                    self.commit_page()?;
-                }
-            }
-        }
-
-        let mut comm = self.comm.borrow_mut();
-        comm.append(&[ClientCommandCode::GetPage as u8]);
-        comm.append(&page_index.to_be_bytes());
-        comm.reply(AppSW::InterruptedExecution);
-
-        let Instruction::Continue(p1, p2) = comm.next_command() else {
-            return Err("INS not supported"); // expected "Continue"
-        };
-
-        if p2 != 0 {
-            return Err("Wrong P2");
-        }
-
-        let fetched_data = comm.get_data().map_err(|_| "Wrong APDU length")?;
-        if fetched_data.len() != PAGE_SIZE - 1 {
-            return Err("Wrong APDU length");
-        }
-        // overwrite page content
-        self.page.data[0..PAGE_SIZE - 1].copy_from_slice(fetched_data);
-        self.page.data[PAGE_SIZE - 1] = p1;
-
-        // update index
-        self.idx = Some(page_index);
-
-        Ok(&mut self.page)
-    }
-}
+use crate::{println, AppSW};
+use super::lib::outsourced_mem::OutsourcedMemory;
 
 
 pub fn handler_start_vapp(comm: &mut io::Comm) -> Result<(), AppSW> {
@@ -128,7 +30,7 @@ pub fn handler_start_vapp(comm: &mut io::Comm) -> Result<(), AppSW> {
     println!("Running app with Manifest: {:?}", manifest);
     println!("hmac: {:?}", hmac);
 
-
+    
     let comm = Rc::new(RefCell::new(comm));
 
     let code_seg = MemorySegment::<OutsourcedMemory>::new(
diff --git a/vm/src/main.rs b/vm/src/main.rs
index 66b66bf..7c02b40 100644
--- a/vm/src/main.rs
+++ b/vm/src/main.rs
@@ -18,14 +18,8 @@
 #![no_std]
 #![no_main]
 
-mod app_ui {
-    pub mod menu;
-}
-mod handlers {
-    pub mod get_version;
-    pub mod register_vapp;
-    pub mod start_vapp;
-}
+mod app_ui;
+mod handlers;
 
 mod settings;