diff --git a/.gitignore b/.gitignore
index eb55056..0b4f101 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,6 @@
 /.clangd
 /.cache
 /.ccls
+
+# private shaders
+/shaders
diff --git a/include/core/commandbuffer.hpp b/include/core/commandbuffer.hpp
index b60c437..20a8105 100644
--- a/include/core/commandbuffer.hpp
+++ b/include/core/commandbuffer.hpp
@@ -4,6 +4,7 @@
 #include "core/commandpool.hpp"
 #include "core/semaphore.hpp"
 #include "device.hpp"
+
 #include <vulkan/vulkan_core.h>
 
 #include <optional>
diff --git a/include/core/shadermodule.hpp b/include/core/shadermodule.hpp
index cdcf3f6..4ef8390 100644
--- a/include/core/shadermodule.hpp
+++ b/include/core/shadermodule.hpp
@@ -3,10 +3,10 @@
 
 #include "device.hpp"
 
-#include <string>
-#include <vector>
 #include <vulkan/vulkan_core.h>
 
+#include <string>
+#include <vector>
 #include <memory>
 
 namespace Vulkan::Core {
diff --git a/src/core/commandbuffer.cpp b/src/core/commandbuffer.cpp
index 15b4b8d..173b15a 100644
--- a/src/core/commandbuffer.cpp
+++ b/src/core/commandbuffer.cpp
@@ -1,5 +1,4 @@
 #include "core/commandbuffer.hpp"
-#include "core/semaphore.hpp"
 #include "utils/exceptions.hpp"
 
 using namespace Vulkan::Core;
diff --git a/src/core/fence.cpp b/src/core/fence.cpp
index b4d6610..25a515d 100644
--- a/src/core/fence.cpp
+++ b/src/core/fence.cpp
@@ -1,6 +1,5 @@
 #include "core/fence.hpp"
 #include "utils/exceptions.hpp"
-#include <vulkan/vulkan_core.h>
 
 using namespace Vulkan::Core;
 
@@ -29,7 +28,7 @@ Fence::Fence(const Device& device) {
 
 void Fence::reset() const {
     if (!this->isValid())
-        throw std::runtime_error("Invalid fence");
+        throw std::logic_error("Invalid fence");
 
     VkFence fenceHandle = this->handle();
     auto res = vkResetFences(this->device, 1, &fenceHandle);
@@ -39,7 +38,7 @@ void Fence::reset() const {
 
 bool Fence::wait(uint64_t timeout) {
     if (!this->isValid())
-        throw std::runtime_error("Invalid fence");
+        throw std::logic_error("Invalid fence");
 
     VkFence fenceHandle = this->handle();
     auto res = vkWaitForFences(this->device, 1, &fenceHandle, VK_TRUE, timeout);
diff --git a/src/core/semaphore.cpp b/src/core/semaphore.cpp
index cc484a9..db4142b 100644
--- a/src/core/semaphore.cpp
+++ b/src/core/semaphore.cpp
@@ -35,7 +35,7 @@ Semaphore::Semaphore(const Device& device, std::optional<uint32_t> initial) {
 
 void Semaphore::signal(uint64_t value) const {
     if (!this->isValid() || !this->isTimeline)
-        throw std::runtime_error("Invalid timeline semaphore");
+        throw std::logic_error("Invalid timeline semaphore");
 
     const VkSemaphoreSignalInfo signalInfo{
         .sType = VK_STRUCTURE_TYPE_SEMAPHORE_SIGNAL_INFO,
@@ -49,7 +49,7 @@ void Semaphore::signal(uint64_t value) const {
 
 bool Semaphore::wait(uint64_t value, uint64_t timeout) {
     if (!this->isValid() || !this->isTimeline)
-        throw std::runtime_error("Invalid timeline semaphore");
+        throw std::logic_error("Invalid timeline semaphore");
 
     VkSemaphore semaphore = this->handle();
     const VkSemaphoreWaitInfo waitInfo{
diff --git a/src/core/shadermodule.cpp b/src/core/shadermodule.cpp
index eb7ecb8..f7258d6 100644
--- a/src/core/shadermodule.cpp
+++ b/src/core/shadermodule.cpp
@@ -29,7 +29,7 @@ ShaderModule::ShaderModule(const Device& device, const std::string& path,
     const uint8_t* data_ptr = code.data();
     const VkShaderModuleCreateInfo createInfo{
         .sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO,
-        .codeSize = code.size() * sizeof(uint32_t),
+        .codeSize = code.size(),
         .pCode = reinterpret_cast<const uint32_t*>(data_ptr)
     };
     VkShaderModule shaderModuleHandle{};
diff --git a/src/device.cpp b/src/device.cpp
index e854a93..d8e1bcf 100644
--- a/src/device.cpp
+++ b/src/device.cpp
@@ -52,6 +52,11 @@ Device::Device(const Instance& instance) {
 
     // create logical device
     const float queuePriority{1.0F}; // highest priority
+    const VkPhysicalDeviceVulkan12Features features{
+        .sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_2_FEATURES,
+        .timelineSemaphore = VK_TRUE,
+        .vulkanMemoryModel = VK_TRUE,
+    };
     const VkDeviceQueueCreateInfo computeQueueDesc{
         .sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO,
         .queueFamilyIndex = *computeFamilyIdx,
@@ -60,6 +65,7 @@ Device::Device(const Instance& instance) {
     };
     const VkDeviceCreateInfo deviceCreateInfo{
         .sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO,
+        .pNext = &features,
         .queueCreateInfoCount = 1,
         .pQueueCreateInfos = &computeQueueDesc
     };
diff --git a/src/instance.cpp b/src/instance.cpp
index 96a6d68..3b829c9 100644
--- a/src/instance.cpp
+++ b/src/instance.cpp
@@ -21,7 +21,7 @@ Instance::Instance() {
         .applicationVersion = VK_MAKE_VERSION(0, 0, 1),
         .pEngineName = "lsfg-vk-base",
         .engineVersion = VK_MAKE_VERSION(0, 0, 1),
-        .apiVersion = VK_API_VERSION_1_4
+        .apiVersion = VK_API_VERSION_1_3
     };
     const VkInstanceCreateInfo createInfo{
         .sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO,
diff --git a/src/main.cpp b/src/main.cpp
index 48c0f86..ca594f8 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,12 +1,29 @@
+#include "core/shadermodule.hpp"
 #include "device.hpp"
 #include "instance.hpp"
 
 #include <iostream>
+#include <vulkan/vulkan_core.h>
 
 int main() {
     const Vulkan::Instance instance;
     const Vulkan::Device device(instance);
 
+    const Vulkan::Core::ShaderModule computeShader(device, "shaders/downsample.spv",
+        {
+            VK_DESCRIPTOR_TYPE_SAMPLER,
+            VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE,
+            VK_DESCRIPTOR_TYPE_STORAGE_IMAGE,
+            VK_DESCRIPTOR_TYPE_STORAGE_IMAGE,
+            VK_DESCRIPTOR_TYPE_STORAGE_IMAGE,
+            VK_DESCRIPTOR_TYPE_STORAGE_IMAGE,
+            VK_DESCRIPTOR_TYPE_STORAGE_IMAGE,
+            VK_DESCRIPTOR_TYPE_STORAGE_IMAGE,
+            VK_DESCRIPTOR_TYPE_STORAGE_IMAGE,
+            VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER
+        }
+    );
+
     std::cerr << "Application finished" << '\n';
     return 0;
 }