diff --git a/src/processor.py b/src/processor.py
index 1234567..abcdefg 100644
--- a/src/processor.py
+++ b/src/processor.py
@@ -1,5 +1,65 @@
 """Data processor module."""


+def process_data(data: dict, config: dict, options: dict | None = None) -> dict:
+    """Process data with many nested conditions."""
+    result = {}
+    options = options or {}
+
+    if data.get("type") == "A":
+        if config.get("mode") == "strict":
+            if options.get("validate"):
+                if data.get("value") > 100:
+                    if config.get("transform"):
+                        result["processed"] = data["value"] * 2
+                    else:
+                        result["processed"] = data["value"]
+                else:
+                    if options.get("default"):
+                        result["processed"] = options["default"]
+                    else:
+                        result["processed"] = 0
+            else:
+                result["processed"] = data.get("value", 0)
+        else:
+            result["processed"] = data.get("value", 0)
+    elif data.get("type") == "B":
+        if config.get("mode") == "strict":
+            if options.get("validate"):
+                if data.get("items"):
+                    result["processed"] = len(data["items"])
+                else:
+                    result["processed"] = 0
+            else:
+                result["processed"] = len(data.get("items", []))
+        else:
+            result["processed"] = len(data.get("items", []))
+    elif data.get("type") == "C":
+        if config.get("mode") == "strict":
+            if options.get("validate"):
+                if data.get("text"):
+                    result["processed"] = data["text"].upper()
+                else:
+                    result["processed"] = ""
+            else:
+                result["processed"] = data.get("text", "").upper()
+        else:
+            result["processed"] = data.get("text", "").upper()
+    else:
+        if config.get("fallback"):
+            result["processed"] = config["fallback"]
+        else:
+            result["processed"] = None
+
+    if options.get("timestamp"):
+        result["timestamp"] = options["timestamp"]
+    if options.get("source"):
+        result["source"] = options["source"]
+
+    return result
+
+
 def simple_function(x: int) -> int:
     """A simple function."""
     return x * 2