diff --git a/Cargo.lock b/Cargo.lock
index df27a86..ef954a3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -168,18 +168,6 @@ dependencies = [
  "trust-dns-resolver 0.19.7",
 ]
 
-[[package]]
-name = "actix-cors"
-version = "0.4.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f3e5c769e4d332bfad27f11b8139b5818c4bbddb02c385b8f16344d93ff1a8eb"
-dependencies = [
- "actix-service 1.0.6",
- "actix-web 3.3.3",
- "derive_more",
- "futures-util",
-]
-
 [[package]]
 name = "actix-cors"
 version = "0.6.0-beta.10"
@@ -845,7 +833,7 @@ dependencies = [
 name = "actix-web-cors"
 version = "1.0.0"
 dependencies = [
- "actix-cors 0.6.0-beta.10",
+ "actix-cors",
  "actix-web 4.0.0-rc.3",
  "env_logger 0.9.0",
  "futures",
@@ -3340,9 +3328,11 @@ dependencies = [
 name = "juniper-advanced"
 version = "1.0.0"
 dependencies = [
- "actix-web 3.3.3",
+ "actix-cors",
+ "actix-web 4.0.0-rc.3",
+ "actix-web-lab",
  "dotenv",
- "env_logger 0.8.4",
+ "env_logger 0.9.0",
  "juniper",
  "log",
  "mysql",
@@ -3357,12 +3347,13 @@ dependencies = [
 name = "juniper-example"
 version = "1.0.0"
 dependencies = [
- "actix-cors 0.4.1",
- "actix-web 3.3.3",
- "env_logger 0.8.4",
+ "actix-cors",
+ "actix-web 4.0.0-rc.3",
+ "actix-web-lab",
+ "env_logger 0.9.0",
  "juniper",
+ "log",
  "serde 1.0.136",
- "serde_derive",
  "serde_json",
 ]
 
diff --git a/basics/middleware-http-to-https/Cargo.toml b/basics/middleware-http-to-https/Cargo.toml
index de47b0b..3bb7437 100644
--- a/basics/middleware-http-to-https/Cargo.toml
+++ b/basics/middleware-http-to-https/Cargo.toml
@@ -4,7 +4,7 @@ version = "1.0.0"
 edition = "2021"
 
 [dependencies]
-actix-web = {version = "4.0.0-beta.21", features = ["rustls"]}
+actix-web = { version = "4.0.0-beta.21", features = ["rustls"] }
 rustls = "0.20.2"
-rustls-pemfile = "0.2.1" # these are now in an external library
+rustls-pemfile = "0.2.1"
 futures = "0.3"
diff --git a/graphql/juniper-advanced/.env.example b/graphql/juniper-advanced/.env.example
index c8f7fc6..61a6ca5 100644
--- a/graphql/juniper-advanced/.env.example
+++ b/graphql/juniper-advanced/.env.example
@@ -1 +1 @@
-DATABASE_URL=mysql://user:password@127.0.0.1/dbname
\ No newline at end of file
+DATABASE_URL=mysql://user:password@127.0.0.1/graphql_testing
diff --git a/graphql/juniper-advanced/Cargo.toml b/graphql/juniper-advanced/Cargo.toml
index db94ea2..d8a5ef1 100644
--- a/graphql/juniper-advanced/Cargo.toml
+++ b/graphql/juniper-advanced/Cargo.toml
@@ -3,20 +3,20 @@ name = "juniper-advanced"
 version = "1.0.0"
 edition = "2021"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
 [dependencies]
-actix-web = "3"
+actix-web = "4.0.0-rc.3"
+actix-web-lab = "0.10"
+actix-cors = "0.6.0-beta.10"
 
 juniper = "0.15"
 
 mysql = "17"
 r2d2 = "0.8"
-r2d2_mysql = "17.0"
+r2d2_mysql = "17"
 
 dotenv = "0.15"
-env_logger = "0.8"
+env_logger = "0.9"
 log = "0.4"
-serde = { version = "1.0", features = ["derive"] }
-serde_json = "1.0"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
 uuid = { version = "0.8", features = ["serde", "v4"] }
diff --git a/graphql/juniper-advanced/README.md b/graphql/juniper-advanced/README.md
index 26f4d27..139ef45 100644
--- a/graphql/juniper-advanced/README.md
+++ b/graphql/juniper-advanced/README.md
@@ -1,28 +1,34 @@
 # juniper-advanced
 
-GraphQL Implementation in Rust using Actix, Juniper, and Mysql as Database
+GraphQL Implementation in Rust using Actix, Juniper, and MySQL as Database
 
 ## Prerequisites
 
-- Rust Installed
-- MySql as Database
+- MySQL server
 
 ## Database Configuration
 
-Create a new database for this project, and import the existing database schema has been provided named ```mysql-schema.sql```.
+Create a new database for this project, and import the existing database schema has been provided named `mysql-schema.sql`.
 
-Create ```.env``` file on the root directory of this project and set environment variable named ```DATABASE_URL```, the example file has been provided named ```.env.example```, you can see the format on there.
-
-## Run
+Create `.env` file on the root directory of this project and set environment variable named `DATABASE_URL`, the example file has been provided named `.env.example`, you can see the format in there.
+
+```sh
+cat mysql-schema.sql | mysql -u root -D graphql_testing
+```
+
+## Usage
 
 ```sh
-# go to the root dir
 cd graphql/juniper-advanced
+cp .env.example .env
+# edit .env and insert your DB credentials
 cargo run
 ```
 
 ## GraphQL Playground
 
+GraphQL provides its own documentation. Click the "docs" link in the top right of the GraphiQL UI to see what types of queries and mutations are possible.
+
+```
+http://localhost:8080/graphiql
 ```
-http://127.0.0.1:8080/graphiql
-```
\ No newline at end of file
diff --git a/graphql/juniper-advanced/mysql-schema.sql b/graphql/juniper-advanced/mysql-schema.sql
index a20e315..40f5a3a 100644
--- a/graphql/juniper-advanced/mysql-schema.sql
+++ b/graphql/juniper-advanced/mysql-schema.sql
@@ -1,6 +1,6 @@
 -- MySQL dump 10.13  Distrib 8.0.16, for osx10.14 (x86_64)
 --
--- Host: 127.0.0.1    Database: rust_graphql
+-- Host: 127.0.0.1    Database: graphql_testing
 -- ------------------------------------------------------
 -- Server version	8.0.15
 
diff --git a/graphql/juniper-advanced/src/handlers.rs b/graphql/juniper-advanced/src/handlers.rs
index 458c67b..2b693d1 100644
--- a/graphql/juniper-advanced/src/handlers.rs
+++ b/graphql/juniper-advanced/src/handlers.rs
@@ -1,10 +1,14 @@
-use actix_web::{web, Error, HttpResponse};
-use juniper::http::graphiql::graphiql_source;
-use juniper::http::GraphQLRequest;
+use actix_web::{get, route, web, Error, HttpResponse, Responder};
+use actix_web_lab::respond::Html;
+use juniper::http::{graphiql::graphiql_source, GraphQLRequest};
 
-use crate::db::Pool;
-use crate::schemas::root::{create_schema, Context, Schema};
+use crate::{
+    db::Pool,
+    schemas::root::{create_schema, Context, Schema},
+};
 
+/// GraphQL endpoint
+#[route("/graphql", method = "GET", method = "POST")]
 pub async fn graphql(
     pool: web::Data<Pool>,
     schema: web::Data<Schema>,
@@ -13,27 +17,21 @@ pub async fn graphql(
     let ctx = Context {
         dbpool: pool.get_ref().to_owned(),
     };
-    let res = web::block(move || {
-        let res = data.execute_sync(&schema, &ctx);
-        serde_json::to_string(&res)
-    })
-    .await
-    .map_err(Error::from)?;
 
-    Ok(HttpResponse::Ok()
-        .content_type("application/json")
-        .body(res))
+    let res = data.execute(&schema, &ctx).await;
+
+    Ok(HttpResponse::Ok().json(res))
 }
 
-pub async fn graphql_playground() -> HttpResponse {
-    HttpResponse::Ok()
-        .content_type("text/html; charset=utf-8")
-        .body(graphiql_source("/graphql", None))
+/// GraphiQL UI
+#[get("/graphiql")]
+async fn graphql_playground() -> impl Responder {
+    Html(graphiql_source("/graphql", None))
 }
 
 pub fn register(config: &mut web::ServiceConfig) {
     config
-        .data(create_schema())
-        .route("/graphql", web::post().to(graphql))
-        .route("/graphiql", web::get().to(graphql_playground));
+        .app_data(web::Data::new(create_schema()))
+        .service(graphql)
+        .service(graphql_playground);
 }
diff --git a/graphql/juniper-advanced/src/main.rs b/graphql/juniper-advanced/src/main.rs
index a52a413..1cfe895 100644
--- a/graphql/juniper-advanced/src/main.rs
+++ b/graphql/juniper-advanced/src/main.rs
@@ -1,32 +1,33 @@
 #[macro_use]
 extern crate juniper;
-extern crate r2d2;
-extern crate r2d2_mysql;
-extern crate serde_json;
 
-use actix_web::{middleware, web, App, HttpServer};
-
-use crate::db::get_db_pool;
-use crate::handlers::register;
+use actix_cors::Cors;
+use actix_web::{middleware::Logger, web::Data, App, HttpServer};
 
 mod db;
 mod handlers;
 mod schemas;
 
+use self::{db::get_db_pool, handlers::register};
+
 #[actix_web::main]
 async fn main() -> std::io::Result<()> {
     dotenv::dotenv().ok();
-    std::env::set_var("RUST_LOG", "actix_web=info,info");
-    env_logger::init();
+    env_logger::init_from_env(env_logger::Env::new().default_filter_or("info"));
+
     let pool = get_db_pool();
 
+    log::info!("starting HTTP server on port 8080");
+    log::info!("the GraphiQL interface HTTP server at http://localhost:8080/graphiql");
+
     HttpServer::new(move || {
         App::new()
-            .data(pool.clone())
-            .wrap(middleware::Logger::default())
+            .app_data(Data::new(pool.clone()))
             .configure(register)
-            .default_service(web::to(|| async { "404" }))
+            .wrap(Cors::permissive())
+            .wrap(Logger::default())
     })
+    .workers(2)
     .bind(("127.0.0.1", 8080))?
     .run()
     .await
diff --git a/graphql/juniper/src/main.rs b/graphql/juniper/src/main.rs
index 3a50ab5..89e2e3b 100644
--- a/graphql/juniper/src/main.rs
+++ b/graphql/juniper/src/main.rs
@@ -17,9 +17,9 @@ mod schema;
 
 use crate::schema::{create_schema, Schema};
 
-/// GraphiQL UI
+/// GraphiQL playground UI
 #[get("/graphiql")]
-async fn graphiql() -> impl Responder {
+async fn graphql_playground() -> impl Responder {
     Html(graphiql_source("/graphql", None))
 }
 
@@ -47,7 +47,7 @@ async fn main() -> io::Result<()> {
         App::new()
             .app_data(Data::from(schema.clone()))
             .service(graphql)
-            .service(graphiql)
+            .service(graphql_playground)
             // the graphiql UI requires CORS to be enabled
             .wrap(Cors::permissive())
             .wrap(middleware::Logger::default())