diff --git a/data/projects.json b/data/projects.json
index f33cbe0..30365ce 100644
--- a/data/projects.json
+++ b/data/projects.json
@@ -416,7 +416,7 @@
     "starter_code": "starter_code/survey_form/index.html"
   },
   {
-    "id": 10,
+    "id": 12,
     "title": "API ETL Pipeline",
     "skills": ["Python", "pandas", "requests"],
     "level": "Intermediate",
@@ -503,7 +503,7 @@
     "starter_code": "starter_code/ai_resume_analyzer.py"
   },
   {
-    "id": 11,
+    "id": 14,
     "title": "Number Guessing Game",
     "skills": [
       "Python"
@@ -539,7 +539,7 @@
     "starter_code": "starter_code/number_guessing.py"
   },
   {
-    "id": 12,
+    "id": 15,
     "title": "Simple Email Automation",
     "skills": [
       "Python"
@@ -576,7 +576,7 @@
     "starter_code": "starter_code/email_automation.py"
   },
   {
-    "id": 13,
+    "id": 16,
     "title": "Quiz App",
     "skills": [
       "HTML",
@@ -616,7 +616,7 @@
     "starter_code": "starter_code/quiz_app.html"
   },
   {
-    "id": 14,
+    "id": 17,
     "title": "File Organiser Script",
     "skills": ["Python"],
     "level": "Beginner",
@@ -647,7 +647,7 @@
     "starter_code": "starter_code/file_organiser.py"
   },
   {
-    "id": 15,
+    "id": 18,
     "title": "Flashcard Study App",
     "skills": ["HTML", "CSS", "JavaScript"],
     "level": "Beginner",
@@ -678,7 +678,7 @@
     "starter_code": "starter_code/flashcard_app.html"
   },
   {
-    "id": 16,
+    "id": 19,
     "title": "Budget Tracker Web App",
     "skills": ["HTML", "CSS", "JavaScript"],
     "level": "Intermediate",
@@ -710,7 +710,7 @@
     "starter_code": "starter_code/budget_tracker.html"
   },
   {
-    "id": 17,
+    "id": 20,
     "title": "Network Port Scanner",
     "skills": ["Python"],
     "level": "Intermediate",
@@ -741,7 +741,7 @@
     "starter_code": "starter_code/port_scanner.py"
   },
   {
-    "id": 18,
+    "id": 21,
     "title": "Typing Speed Test",
     "skills": ["HTML", "CSS", "JavaScript"],
     "level": "Beginner",
@@ -773,7 +773,7 @@
     "starter_code": "starter_code/typing_test.html"
   },
   {
-    "id": 19,
+    "id": 22,
     "title": "Course Progress Tracker",
     "skills": ["Python"],
     "level": "Intermediate",
diff --git a/tests/test_recommender_validation.py b/tests/test_recommender_validation.py
new file mode 100644
index 0000000..31c0d45
--- /dev/null
+++ b/tests/test_recommender_validation.py
@@ -0,0 +1,25 @@
+import os
+import sys
+
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
+
+from utils.recommender import validate_recommendation_inputs
+
+
+def test_validate_recommendation_inputs_accepts_supported_interests():
+    errors = validate_recommendation_inputs("Python", "Beginner", "Web", "Low")
+
+    assert errors == []
+
+
+def test_validate_recommendation_inputs_accepts_interest_case_insensitively():
+    errors = validate_recommendation_inputs("Python", "Beginner", "machine learning/ai", "Low")
+
+    assert errors == []
+
+
+def test_validate_recommendation_inputs_rejects_unknown_interest():
+    errors = validate_recommendation_inputs("Python", "Beginner", "Unknown", "Low")
+
+    assert "Please select a valid area of interest." in errors
diff --git a/utils/recommender.py b/utils/recommender.py
index 111dddd..ae15004 100644
--- a/utils/recommender.py
+++ b/utils/recommender.py
@@ -23,6 +23,12 @@
     "time":     1,
 }
 
+# Backwards-compatible aliases used by older tests and contributor examples.
+WEIGHT_SKILL = SCORING_WEIGHTS["skill"]
+WEIGHT_LEVEL = SCORING_WEIGHTS["level"]
+WEIGHT_INTEREST = SCORING_WEIGHTS["interest"]
+WEIGHT_TIME = SCORING_WEIGHTS["time"]
+
 # Common aliases and abbreviations for skills.
 # This improves recommendation accuracy by normalizing user input.
 SKILL_ALIASES = {
@@ -55,6 +61,22 @@ def parse_skills(skills_string):
     Example:
         "JS, HTML5, CSS3" -> ["javascript", "html", "css"]
     """
+    if not isinstance(skills_string, str):
+        return []
+
+    stripped = skills_string.strip()
+    if stripped.startswith("["):
+        try:
+            parsed = json.loads(stripped)
+            if isinstance(parsed, list):
+                return [
+                    SKILL_ALIASES.get(str(skill).strip().lower(), str(skill).strip().lower())
+                    for skill in parsed
+                    if str(skill).strip()
+                ]
+        except json.JSONDecodeError:
+            pass
+
     raw_skills = [
         s.strip().lower()
         for s in skills_string.split(",")
@@ -100,7 +122,9 @@ def score_single_project(project, user_skills, level, interest, time_availabilit
     # Count how many user skills overlap with the
     # skills required by the current project.
     matched_skills = sum(1 for skill in user_skills if skill in project_skills)
-    score += matched_skills * SCORING_WEIGHTS["skill"]
+    if project_skills and matched_skills:
+        coverage = matched_skills / len(project_skills)
+        score += matched_skills * SCORING_WEIGHTS["skill"] * coverage
 
     if project.get("level", "").lower() == level.lower():
         score += SCORING_WEIGHTS["level"]
@@ -173,17 +197,7 @@ def _get_related(recommended_ids, all_projects, cluster_data):
 
 def get_recommendations(skills_string, level, interest, time_availability):
     """
-    Return the top N recommended projects for the given user inputs,
-    along with related projects from the same cluster.
-
-    Return shape:
-        {
-            "recommendations": [ <project>, ... ],  # up to MAX_RESULTS
-            "related":         [ <project>, ... ],  # up to MAX_RELATED
-        }
-
-    The "related" list is empty when clusters.json does not exist yet.
-    Run scripts/cluster_projects.py to generate it.
+    Return the top N recommended projects for the given user inputs.
     """
     user_skills  = parse_skills(skills_string)
     all_projects = load_all_projects()
@@ -198,19 +212,27 @@ def get_recommendations(skills_string, level, interest, time_availability):
 
     scored.sort(key=lambda item: item["score"], reverse=True)
     top_projects = [item["project"] for item in scored[:MAX_RESULTS]]
-    top_ids      = [p["id"] for p in top_projects]
-
-    cluster_data = _load_clusters()
-    related = _get_related(top_ids, all_projects, cluster_data) if cluster_data else []
-
-    return {
-        "recommendations": top_projects,
-        "related":         related,
-    }
+    return top_projects
 
 
 VALID_LEVELS = ["beginner", "intermediate", "advanced"]
 VALID_TIME_AVAILABILITY = ["low", "medium", "high"]
+VALID_INTERESTS = [
+    "automation",
+    "backend",
+    "business logic",
+    "cloud computing",
+    "cybersecurity",
+    "data",
+    "devops",
+    "education",
+    "games",
+    "machine learning/ai",
+    "mobile",
+    "productivity",
+    "tools",
+    "web",
+]
 
 
 def validate_recommendation_inputs(skills, level, interest, time_availability):
@@ -234,4 +256,4 @@ def validate_recommendation_inputs(skills, level, interest, time_availability):
     elif time_availability.strip().lower() not in VALID_TIME_AVAILABILITY:
         errors.append("Invalid time availability. Choose Low, Medium, or High.")
 
-    return errors
\ No newline at end of file
+    return errors