diff --git a/backend/migrations/20240406031915_create_applications.sql b/backend/migrations/20240406031915_create_applications.sql
index b62d6c1a..ffcbba42 100644
--- a/backend/migrations/20240406031915_create_applications.sql
+++ b/backend/migrations/20240406031915_create_applications.sql
@@ -22,8 +22,8 @@ CREATE TABLE applications (
 
 CREATE TABLE application_roles (
     id BIGSERIAL PRIMARY KEY,
-    application_id INTEGER NOT NULL,
-    campaign_role_id INTEGER NOT NULL,
+    application_id BIGINT NOT NULL,
+    campaign_role_id BIGINT NOT NULL,
     CONSTRAINT FK_application_roles_applications
         FOREIGN KEY(application_id)
             REFERENCES applications(id)
diff --git a/backend/server/src/models/application.rs b/backend/server/src/models/application.rs
new file mode 100644
index 00000000..f3bff5ff
--- /dev/null
+++ b/backend/server/src/models/application.rs
@@ -0,0 +1,87 @@
+use crate::models::error::ChaosError;
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
+use snowflake::SnowflakeIdGenerator;
+use sqlx::{FromRow, Pool, Postgres, Transaction};
+use std::ops::DerefMut;
+
+#[derive(Deserialize, Serialize, Clone, FromRow, Debug)]
+pub struct Application {
+    pub id: i64,
+    pub campaign_id: i64,
+    pub user_id: i64,
+    pub status: ApplicationStatus,
+    pub private_status: ApplicationStatus,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+}
+
+/*
+    User could apply for more than one roles at a time, for each application
+    into a role it will be represented by row in application_roles table which
+    is linked to the main Application body through application_id
+*/
+#[derive(Deserialize, Serialize, Clone, FromRow, Debug)]
+pub struct ApplicationRole {
+    pub id: i64,
+    pub application_id: i64,
+    pub campaign_role_id: i64,
+}
+
+pub struct NewApplication {
+    pub user_id: i64,
+    pub status: ApplicationStatus,
+    pub private_status: ApplicationStatus,
+    pub applied_roles: Vec<ApplicationRole>,
+}
+
+
+#[derive(Deserialize, Serialize, sqlx::Type, Clone, Debug)]
+#[sqlx(type_name = "application_status", rename_all = "PascalCase")]
+pub enum ApplicationStatus {
+    Pending,
+    Rejected,
+    Successful,
+}
+
+impl Application {
+    pub async fn create(
+        campaign_id: i64,
+        application_data: NewApplication,
+        mut snowflake_generator: SnowflakeIdGenerator,
+        transaction: &mut Transaction<'_, Postgres>,
+    ) -> Result<(), ChaosError> {
+        let id = snowflake_generator.generate();
+
+        // Insert into table applications
+        sqlx::query!(
+            "
+                INSERT INTO applications (id, campaign_id, user_id, status, private_status)
+                VALUES ($1, $2, $3, $4, $5)
+            ",
+            id,
+            campaign_id,
+            application_data.user_id,
+            application_data.status as ApplicationStatus,
+            application_data.private_status as ApplicationStatus,
+        )
+        .execute(transaction.deref_mut())
+        .await?;
+
+        // Insert into table application_roles
+        for role_applied in application_data.applied_roles {
+            sqlx::query!(
+                "
+                    INSERT INTO application_roles (application_id, campaign_role_id)
+                    VALUES ($1, $2)
+                ",
+                id,
+                role_applied.campaign_role_id
+            )
+            .execute(transaction.deref_mut())
+            .await?;
+        }
+
+        Ok(())
+    }
+}
\ No newline at end of file
diff --git a/backend/server/src/models/mod.rs b/backend/server/src/models/mod.rs
index 76102f22..0af7da1a 100644
--- a/backend/server/src/models/mod.rs
+++ b/backend/server/src/models/mod.rs
@@ -7,3 +7,4 @@ pub mod role;
 pub mod storage;
 pub mod transaction;
 pub mod user;
+pub mod application;
diff --git a/backend/server/src/models/role.rs b/backend/server/src/models/role.rs
index 1d5386c7..bddc6cae 100644
--- a/backend/server/src/models/role.rs
+++ b/backend/server/src/models/role.rs
@@ -6,7 +6,7 @@ use sqlx::{FromRow, Pool, Postgres};
 
 #[derive(Deserialize, Serialize, Clone, FromRow, Debug)]
 pub struct Role {
-    pub id: i32,
+    pub id: i64,
     pub campaign_id: i64,
     pub name: Option<String>,
     pub description: String,