diff --git a/src/advrobotics_lab3_app/CMakeLists.txt b/src/advrobotics_lab3_app/CMakeLists.txt
index 9aa9058..0691d05 100644
--- a/src/advrobotics_lab3_app/CMakeLists.txt
+++ b/src/advrobotics_lab3_app/CMakeLists.txt
@@ -17,8 +17,8 @@ target_include_directories(build_tower PUBLIC
 target_compile_features(build_tower PUBLIC c_std_99 cxx_std_17)  # Require C99 and C++17
 ament_target_dependencies(
   build_tower
-  "[rclcpp"
-  "advrobotics_lab3_interfaces]"
+  "rclcpp"
+  "advrobotics_lab3_interfaces"
 )
 
 install(TARGETS build_tower
diff --git a/src/advrobotics_lab3_app/package.xml b/src/advrobotics_lab3_app/package.xml
index 8cc57aa..eb9b05e 100644
--- a/src/advrobotics_lab3_app/package.xml
+++ b/src/advrobotics_lab3_app/package.xml
@@ -9,8 +9,8 @@
 
   <buildtool_depend>ament_cmake</buildtool_depend>
 
-  <depend>[rclcpp</depend>
-  <depend>advrobotics_lab3_interfaces]</depend>
+  <depend>rclcpp</depend>
+  <depend>advrobotics_lab3_interfaces</depend>
 
   <test_depend>ament_lint_auto</test_depend>
   <test_depend>ament_lint_common</test_depend>
diff --git a/src/advrobotics_lab3_app/src/build_tower.cpp b/src/advrobotics_lab3_app/src/build_tower.cpp
index a30ab67..4e11cfb 100644
--- a/src/advrobotics_lab3_app/src/build_tower.cpp
+++ b/src/advrobotics_lab3_app/src/build_tower.cpp
@@ -1,10 +1,139 @@
-#include <cstdio>
+#include <chrono>
+#include <memory>
+#include <cmath>
 
-int main(int argc, char ** argv)
+#include "rclcpp/rclcpp.hpp"
+#include "advrobotics_lab3_interfaces/msg/joints.hpp"
+#include "advrobotics_lab3_interfaces/msg/gripper.hpp"
+#include "advrobotics_lab3_interfaces/srv/invkin.hpp"
+
+using namespace std::chrono_literals;
+
+class BuildTower : public rclcpp::Node
 {
-  (void) argc;
-  (void) argv;
+public:
+    BuildTower() : Node("build_tower")
+    {
+        joint_cmd_pub_ = create_publisher<advrobotics_lab3_interfaces::msg::Joints>("joint_cmd", 10);
+        gripper_cmd_pub_ = create_publisher<advrobotics_lab3_interfaces::msg::Gripper>("gripper_cmd", 10);
 
-  printf("hello world advrobotics_lab3_app package\n");
-  return 0;
+        joint_pos_sub_ = create_subscription<advrobotics_lab3_interfaces::msg::Joints>(
+            "joint_position", 10,
+            std::bind(&BuildTower::jointPosCallback, this, std::placeholders::_1));
+
+        ik_client_ = create_client<advrobotics_lab3_interfaces::srv::Invkin>("invkin");
+
+        while (!ik_client_->wait_for_service(1s))
+            RCLCPP_INFO(get_logger(), "Waiting for IK service...");
+
+        executeTower();
+    }
+
+private:
+    /* ---------------- CALLBACKS ---------------- */
+
+    void jointPosCallback(const advrobotics_lab3_interfaces::msg::Joints::SharedPtr msg)
+    {
+        current_q1_ = msg->q1;
+        current_q2_ = msg->q2;
+        current_q3_ = msg->q3;
+    }
+
+    /* ---------------- MOTION PRIMITIVES ---------------- */
+
+    void moveToCartesian(double x, double y, double z)
+    {
+        auto request = std::make_shared<advrobotics_lab3_interfaces::srv::Invkin::Request>();
+        request->x = x;
+        request->y = y;
+        request->z = z;
+
+        auto future = ik_client_->async_send_request(request);
+        rclcpp::spin_until_future_complete(shared_from_this(), future);
+
+        auto response = future.get();
+
+        advrobotics_lab3_interfaces::msg::Joints cmd;
+        cmd.q1 = response->q1 * 180.0 / M_PI;
+        cmd.q2 = response->q2 * 180.0 / M_PI;
+        cmd.q3 = response->q3 * 180.0 / M_PI;
+
+        joint_cmd_pub_->publish(cmd);
+        waitUntilReached(cmd);
+    }
+
+    void waitUntilReached(const advrobotics_lab3_interfaces::msg::Joints &target)
+    {
+        while (rclcpp::ok())
+        {
+            if (std::fabs(current_q1_ - target.q1) < 2.0 &&
+                std::fabs(current_q2_ - target.q2) < 2.0 &&
+                std::fabs(current_q3_ - target.q3) < 2.0)
+                break;
+
+            rclcpp::sleep_for(100ms);
+        }
+    }
+
+    void setGripper(double angle)
+    {
+        advrobotics_lab3_interfaces::msg::Gripper g;
+        g.gripper = angle;
+        gripper_cmd_pub_->publish(g);
+        rclcpp::sleep_for(1s);
+    }
+
+    /* ---------------- MAIN LOGIC ---------------- */
+
+    void executeTower()
+    {
+        constexpr double pick_x = 0.10;
+        constexpr double pick_y = 0.10;
+        constexpr double pick_z = 0.02;
+
+        constexpr double place_x = 0.15;
+        constexpr double place_y = 0.0;
+        constexpr double base_z  = 0.02;
+        constexpr double block_height = 0.03;
+
+        constexpr double approach_z = 0.10;
+        constexpr double gripper_open = 30.0;
+        constexpr double gripper_closed = -10.0;
+
+        setGripper(gripper_open);
+
+        for (int i = 0; i < 3; ++i)
+        {
+            double place_z = base_z + i * block_height;
+
+            moveToCartesian(pick_x, pick_y, approach_z);
+            moveToCartesian(pick_x, pick_y, pick_z);
+            setGripper(gripper_closed);
+
+            moveToCartesian(pick_x, pick_y, approach_z);
+            moveToCartesian(place_x, place_y, approach_z);
+            moveToCartesian(place_x, place_y, place_z);
+
+            setGripper(gripper_open);
+            moveToCartesian(place_x, place_y, approach_z);
+        }
+
+        RCLCPP_INFO(get_logger(), "Tower completed.");
+    }
+
+private:
+    rclcpp::Publisher<advrobotics_lab3_interfaces::msg::Joints>::SharedPtr joint_cmd_pub_;
+    rclcpp::Publisher<advrobotics_lab3_interfaces::msg::Gripper>::SharedPtr gripper_cmd_pub_;
+    rclcpp::Subscription<advrobotics_lab3_interfaces::msg::Joints>::SharedPtr joint_pos_sub_;
+    rclcpp::Client<advrobotics_lab3_interfaces::srv::Invkin>::SharedPtr ik_client_;
+
+    double current_q1_{0.0}, current_q2_{0.0}, current_q3_{0.0};
+};
+
+int main(int argc, char **argv)
+{
+    rclcpp::init(argc, argv);
+    rclcpp::spin(std::make_shared<BuildTower>());
+    rclcpp::shutdown();
+    return 0;
 }