diff --git a/backend/src/main/java/cx/flamingo/analysis/service/LanguageService.java b/backend/src/main/java/cx/flamingo/analysis/service/LanguageService.java
index 594a906..f209bb6 100644
--- a/backend/src/main/java/cx/flamingo/analysis/service/LanguageService.java
+++ b/backend/src/main/java/cx/flamingo/analysis/service/LanguageService.java
@@ -5,6 +5,7 @@
 import java.io.InputStreamReader;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Optional;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -72,11 +73,10 @@ public List<Language> autocompleteLanguages(String query, int maxResults) {
             .collect(Collectors.toList());
     }
 
-    public Language getLanguageById(String id) {
+    public Optional<Language> getLanguageById(String id) {
         return languages.stream()
             .filter(l -> l.getId().equals(id))
-            .findFirst()
-            .orElse(null);
+            .findFirst();
     }
 
     public List<Language> getAllLanguages() {
@@ -89,4 +89,4 @@ public Language getDefaultLanguage() {
             .findFirst()
             .orElseThrow(() -> new RuntimeException("Default language (Java) not found"));
     }
-} 
\ No newline at end of file
+} 
diff --git a/backend/src/main/java/cx/flamingo/analysis/service/RegionService.java b/backend/src/main/java/cx/flamingo/analysis/service/RegionService.java
index ff7deb6..24fdfbe 100644
--- a/backend/src/main/java/cx/flamingo/analysis/service/RegionService.java
+++ b/backend/src/main/java/cx/flamingo/analysis/service/RegionService.java
@@ -5,35 +5,39 @@
 import java.io.InputStreamReader;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.stereotype.Service;
 
 import cx.flamingo.analysis.model.City;
 import cx.flamingo.analysis.model.Region;
 import jakarta.annotation.PostConstruct;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 
 @Slf4j
 @Service
+@RequiredArgsConstructor
 public class RegionService {
     private List<Region> regions;
+    private Map<String, Integer> regionPopulationCache;
 
-    @Autowired
-    private StateService stateService;
+    private final StateService stateService;
 
-    @Autowired
-    private CityService cityService;
+    private final CityService cityService;
 
     @PostConstruct
     public void init() {
         loadRegions();
         log.info("Loaded {} regions", regions.size());
+        buildPopulationCache();
     }
 
     private void loadRegions() {
@@ -71,6 +75,15 @@ private void loadRegions() {
         }
     }
 
+    private void buildPopulationCache() {
+        regionPopulationCache = new HashMap<>();
+        for (City city : cityService.getAllCities()) {
+            for (String regionId : city.getRegionIds()) {
+                regionPopulationCache.merge(regionId, city.getPopulation(), Integer::sum);
+            }
+        }
+    }
+
     public void updateRegion(Region updatedRegion) {
         int index = -1;
         for (int i = 0; i < regions.size(); i++) {
@@ -88,10 +101,7 @@ public void updateRegion(Region updatedRegion) {
     }
 
     private int getRegionTotalPopulation(Region region) {
-        return cityService.getAllCities().stream()
-            .filter(city -> city.getRegionIds().contains(region.getId()))
-            .mapToInt(City::getPopulation)
-            .sum();
+        return regionPopulationCache.getOrDefault(region.getId(), 0);
     }
 
     public List<Region> autocompleteRegions(String query, String stateId, List<String> cityIds, int maxResults) {
@@ -122,21 +132,19 @@ public List<Region> autocompleteRegions(String query, String stateId, List<Strin
             .collect(Collectors.toList());
     }
 
-    public Region getRegionById(String id) {
+    public Optional<Region> getRegionById(String id) {
         return regions.stream()
             .filter(r -> r.getId().equals(id))
-            .findFirst()
-            .orElse(null);
+            .findFirst();
     }
 
-    public Region getRegionByName(String name) {
+    public Optional<Region> getRegionByName(String name) {
         return regions.stream()
             .filter(r -> r.getName().equalsIgnoreCase(name))
-            .findFirst()
-            .orElse(null);
+            .findFirst();
     }
 
     public List<Region> getAllRegions() {
         return new ArrayList<>(regions);
     }
-} 
\ No newline at end of file
+} 
diff --git a/backend/src/main/java/cx/flamingo/analysis/service/StateService.java b/backend/src/main/java/cx/flamingo/analysis/service/StateService.java
index 3eabd47..b881ba2 100644
--- a/backend/src/main/java/cx/flamingo/analysis/service/StateService.java
+++ b/backend/src/main/java/cx/flamingo/analysis/service/StateService.java
@@ -4,8 +4,11 @@
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -24,6 +27,7 @@
 @Service
 public class StateService {
     private List<State> states;
+    private Map<String, Integer> statePopulationCache;
 
     private final CityService cityService;
 
@@ -36,6 +40,7 @@ public StateService(@Lazy CityService cityService) {
     public void init() {
         loadStates();
         log.info("Loaded {} states", states.size());
+        buildPopulationCache();
     }
 
     private void loadStates() {
@@ -70,11 +75,15 @@ private void loadStates() {
         }
     }
 
+    private void buildPopulationCache() {
+        statePopulationCache = new HashMap<>();
+        for (City city : cityService.getAllCities()) {
+            statePopulationCache.merge(city.getStateId(), city.getPopulation(), Integer::sum);
+        }
+    }
+
     private int getStateTotalPopulation(State state) {
-        return cityService.getAllCities().stream()
-            .filter(city -> city.getStateId().equals(state.getId()))
-            .mapToInt(City::getPopulation)
-            .sum();
+        return statePopulationCache.getOrDefault(state.getId(), 0);
     }
 
     public List<State> autocompleteStates(String query, String regionId, List<String> cityIds, int maxResults) {
@@ -105,21 +114,19 @@ public List<State> autocompleteStates(String query, String regionId, List<String
             .collect(Collectors.toList());
     }
 
-    public State getStateById(String id) {
+    public Optional<State> getStateById(String id) {
         return states.stream()
             .filter(s -> s.getId().equals(id))
-            .findFirst()
-            .orElse(null);
+            .findFirst();
     }
 
-    public State getStateByCode(String code) {
+    public Optional<State> getStateByCode(String code) {
         return states.stream()
             .filter(s -> s.getCode().equalsIgnoreCase(code))
-            .findFirst()
-            .orElse(null);
+            .findFirst();
     }
 
     public List<State> getAllStates() {
         return new ArrayList<>(states);
     }
-} 
\ No newline at end of file
+}