diff --git a/Week04/decorators_okay_sezer.py b/Week04/decorators_okay_sezer.py
new file mode 100644
index 00000000..5c87c45a
--- /dev/null
+++ b/Week04/decorators_okay_sezer.py
@@ -0,0 +1,43 @@
+import time
+import tracemalloc
+from functools import wraps
+
+def performance(func):
+    """
+      A decorator that measures and tracks the performance of decorated functions.
+    
+    Attributes:
+        counter (int): The number of times the decorated function has been called.
+        total_time (float): The cumulative execution time (in seconds) of all calls.
+        total_mem (int): The cumulative memory usage (in bytes) of all calls.
+
+    Args:
+        func (callable): The function to be decorated.
+
+    Returns:
+        callable: A wrapper function that executes the original function while tracking performance metrics
+     """
+
+    @wraps(func)
+    def wrapper(*args, **kwargs):
+        tracemalloc.start()
+        
+        start_time = time.perf_counter()
+        result = func(*args, **kwargs)
+        end_time = time.perf_counter()
+        
+        current, peak = tracemalloc.get_traced_memory()
+        tracemalloc.stop()
+        
+        performance.counter += 1
+        performance.total_time += (end_time - start_time)
+        performance.total_mem += current
+        
+        return result
+    
+    return wrapper
+
+
+performance.counter = 0
+performance.total_time = 0.0
+performance.total_mem = 0
diff --git a/Week04/functions_okay_sezer.py b/Week04/functions_okay_sezer.py
new file mode 100644
index 00000000..6fe28995
--- /dev/null
+++ b/Week04/functions_okay_sezer.py
@@ -0,0 +1,34 @@
+custom_power = lambda x=0, /, e=1: x ** e
+
+def custom_equation(x: int = 0, y: int = 0, /, a: int = 1, b: int = 1, *, c: int = 1) -> float:
+    """
+    This function solves the equation (x**a + y**b) / c.
+
+    :param x: The value of x in the equation. Default is 0.
+    :param y: The value of y in the equation. Default is 0.
+    :param a: The coefficient of x in the equation. Default is 1.
+    :param b: The coefficient of y in the equation. Default is 1.
+    :param c: The constant term in the equation. Default is 1.
+    :return: The result of the equation.
+    """
+    for name, val in [("x", x), ("y", y), ("a", a), ("b", b), ("c", c)]:
+        if not isinstance(val, int):
+            raise TypeError(f"{name} must be an integer")
+    return (x**a + y**b) / c
+
+
+def fn_w_counter() -> (int, dict[str, int]):   
+    if not hasattr(fn_w_counter, "total_calls"):
+        fn_w_counter.total_calls = 0
+        fn_w_counter.callers_dict = {}
+
+    fn_w_counter.total_calls += 1
+    caller = fn_w_counter.__module__
+
+    if caller in fn_w_counter.callers_dict:
+        fn_w_counter.callers_dict[caller] += 1
+    else:
+        fn_w_counter.callers_dict[caller] = 1
+
+    return fn_w_counter.total_calls, fn_w_counter.callers_dict
+
diff --git a/Week05/awaitme_okay_sezer.py b/Week05/awaitme_okay_sezer.py
new file mode 100644
index 00000000..ed1af02d
--- /dev/null
+++ b/Week05/awaitme_okay_sezer.py
@@ -0,0 +1,6 @@
+def awaitme(func):
+    """A decorator that allows the decorated function to be called with 'await' syntax, enabling asynchronous behavior."""
+    async def wrapper(*args, **kwargs):
+        return func(*args, **kwargs)
+    
+    return wrapper
\ No newline at end of file
diff --git a/Week06/timer_okay_sezer.py b/Week06/timer_okay_sezer.py
new file mode 100644
index 00000000..3f13f670
--- /dev/null
+++ b/Week06/timer_okay_sezer.py
@@ -0,0 +1,13 @@
+import time
+
+class Timer:
+    def __init__(self):
+        self.start_time = None
+        self.end_time = None
+
+    def __enter__(self):
+        self.start_time = time.time()
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.end_time = time.time()
\ No newline at end of file