diff --git a/README.md b/README.md
index c5bb33b1..32d8b4be 100644
--- a/README.md
+++ b/README.md
@@ -37,6 +37,10 @@ your Fitbit App client ID and client secret. The following tables shows the poss
 <th>Importance</th>
 </tr>
 <tr>
+<td>application.loop.interval.ms</td><td>How often to perform the main application loop (only controls how often to poll for new user registrations).></td><td>long</td><td>300000</td><td></td><td></td></tr>
+<tr>
+<td>user.cache.refresh.interval.ms</td><td>How often to invalidate the cache and poll for new user registrations.</td><td>long</td><td>3600000</td><td></td><td></td></tr>
+<tr>
 <td>rest.source.poll.interval.ms</td><td>How often to poll the source URL.</td><td>long</td><td>60000</td><td></td><td>low</td></tr>
 <tr>
 <td>rest.source.base.url</td><td>Base URL for REST source connector.</td><td>string</td><td></td><td></td><td>high</td></tr>
diff --git a/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/FitbitSourceConnector.java b/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/FitbitSourceConnector.java
index 3b7a6edb..30e14c28 100644
--- a/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/FitbitSourceConnector.java
+++ b/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/FitbitSourceConnector.java
@@ -20,6 +20,7 @@
 import static org.radarbase.connect.rest.fitbit.FitbitRestSourceConnectorConfig.FITBIT_USERS_CONFIG;
 
 import java.io.IOException;
+import java.time.Duration;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -45,9 +46,12 @@ public class FitbitSourceConnector extends AbstractRestSourceConnector {
 
   @Override
   public void start(Map<String, String> props) {
+    logger.info("Starting Fitbit source connector");
     super.start(props);
     executor = Executors.newSingleThreadScheduledExecutor();
 
+    Duration applicationLoopInterval = config.getApplicationLoopInterval();
+
     executor.scheduleAtFixedRate(() -> {
       if (repository.hasPendingUpdates()) {
         try {
@@ -66,7 +70,7 @@ public void start(Map<String, String> props) {
       } else {
         logger.info("No pending updates found. Not attempting to refresh users.");
       }
-    }, 0, 5, TimeUnit.MINUTES);
+    }, 0, applicationLoopInterval.toSeconds(), TimeUnit.SECONDS);
   }
 
   @Override
diff --git a/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/route/FitbitPollingRoute.java b/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/route/FitbitPollingRoute.java
index 53e17b97..e2573143 100644
--- a/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/route/FitbitPollingRoute.java
+++ b/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/route/FitbitPollingRoute.java
@@ -100,7 +100,7 @@ public abstract class FitbitPollingRoute implements PollingRequestRoute {
   protected static final TemporalAmount ONE_SECOND = SECONDS.getDuration();
   protected static final TemporalAmount ONE_MINUTE = MINUTES.getDuration();
 
-  private static final Logger logger = LoggerFactory.getLogger(FitbitSleepRoute.class);
+  private static final Logger logger = LoggerFactory.getLogger(FitbitPollingRoute.class);
 
   /** Committed offsets. */
   private Map<String, Instant> offsets;
@@ -164,7 +164,7 @@ public void requestEmpty(RestRequest request) {
   @Override
   public void requestFailed(RestRequest request, Response response) {
     if (response != null && response.code() == 429) {
-      User user = ((FitbitRestRequest)request).getUser();
+      User user = ((FitbitRestRequest) request).getUser();
       tooManyRequestsForUser.add(user);
       String cooldownString = response.header("Retry-After");
       Duration cooldown = getTooManyRequestsCooldown();
@@ -179,6 +179,8 @@ public void requestFailed(RestRequest request, Response response) {
       lastPollPerUser.put(user.getId(), backOff);
       logger.info("Too many requests for user {}. Backing off until {}",
           user, backOff.plus(getPollIntervalPerUser()));
+    } else if (response != null) {
+      logger.warn("Failed to make request {}. Response is: {}", request, response);
     } else {
       logger.warn("Failed to make request {}", request);
     }
@@ -197,8 +199,11 @@ public Stream<FitbitRestRequest> requests() {
     lastPoll = Instant.now();
     try {
       return userRepository.stream()
+          // Collect Instant of nextPoll for each user
           .map(u -> new AbstractMap.SimpleImmutableEntry<>(u, nextPoll(u)))
+          // Keep users where the lastPoll is later than the nextPoll for the user (i.e., user needs to be polled)
           .filter(u -> lastPoll.isAfter(u.getValue()))
+          // Sort users by nextPoll (old to new?)
           .sorted(Map.Entry.comparingByValue())
           .flatMap(u -> this.createRequests(u.getKey()))
           .filter(Objects::nonNull);
diff --git a/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/user/ServiceUserRepository.kt b/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/user/ServiceUserRepository.kt
index 9c93a576..a29a810f 100644
--- a/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/user/ServiceUserRepository.kt
+++ b/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/user/ServiceUserRepository.kt
@@ -61,9 +61,9 @@ import java.io.IOException
 import java.util.concurrent.ConcurrentHashMap
 import java.util.stream.Stream
 import kotlin.time.Duration.Companion.days
-import kotlin.time.Duration.Companion.hours
 import kotlin.time.Duration.Companion.minutes
 import kotlin.time.Duration.Companion.seconds
+import kotlin.time.toKotlinDuration
 
 @Suppress("unused")
 class ServiceUserRepository : UserRepository {
@@ -92,8 +92,12 @@ class ServiceUserRepository : UserRepository {
             clientSecret = config.fitbitUserRepositoryClientSecret,
         )
 
+        val refreshDuration = config.userCacheRefreshInterval.toKotlinDuration()
         userCache = CachedSet(
-            CacheConfig(refreshDuration = 1.hours, retryDuration = 1.minutes),
+            CacheConfig(
+                refreshDuration = refreshDuration,
+                retryDuration = if (refreshDuration > 1.minutes) 1.minutes else refreshDuration,
+            ),
         ) {
             makeRequest<Users> { url("users?source-type=FitBit") }
                 .users
diff --git a/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/user/ServiceUserRepositoryLegacy.java b/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/user/ServiceUserRepositoryLegacy.java
index 2f5086d4..b06dcce8 100644
--- a/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/user/ServiceUserRepositoryLegacy.java
+++ b/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/user/ServiceUserRepositoryLegacy.java
@@ -246,4 +246,4 @@ private <T> T makeRequest(Request request, ObjectReader reader) throws IOExcepti
        throw new IOException("Failed to make request to user repository", ex);
      }
    }
- }
\ No newline at end of file
+ }
diff --git a/kafka-connect-rest-source/src/main/java/org/radarbase/connect/rest/RestSourceConnectorConfig.java b/kafka-connect-rest-source/src/main/java/org/radarbase/connect/rest/RestSourceConnectorConfig.java
index 6b9d7c70..67eadb31 100644
--- a/kafka-connect-rest-source/src/main/java/org/radarbase/connect/rest/RestSourceConnectorConfig.java
+++ b/kafka-connect-rest-source/src/main/java/org/radarbase/connect/rest/RestSourceConnectorConfig.java
@@ -45,10 +45,15 @@
 public class RestSourceConnectorConfig extends AbstractConfig {
   public static final Pattern COLON_PATTERN = Pattern.compile(":");
 
+  public static final String APPLICATION_LOOP_INTERVAL_CONFIG = "application.loop.interval.ms";
+  private static final String APPLICATION_LOOP_INTERVAL_DOC = "How often to perform the main application loop.";
+  private static final String APPLICATION_LOOP_INTERVAL_DISPLAY = "Application loop interval";
+  private static final Long APPLICATION_LOOP_INTERVAL_DEFAULT = 300000L; // 5 minutes
+
   private static final String SOURCE_POLL_INTERVAL_CONFIG = "rest.source.poll.interval.ms";
   private static final String SOURCE_POLL_INTERVAL_DOC = "How often to poll the source URL.";
   private static final String SOURCE_POLL_INTERVAL_DISPLAY = "Polling interval";
-  private static final Long SOURCE_POLL_INTERVAL_DEFAULT = 60000L;
+  private static final Long SOURCE_POLL_INTERVAL_DEFAULT = 60000L; // 1 minute
 
   static final String SOURCE_URL_CONFIG = "rest.source.base.url";
   private static final String SOURCE_URL_DOC = "Base URL for REST source connector.";
@@ -81,6 +86,11 @@ public class RestSourceConnectorConfig extends AbstractConfig {
       "Class to be used to generate REST requests";
   private static final String REQUEST_GENERATOR_DISPLAY = "Request generator class";
 
+  public static final String USER_CACHE_REFRESH_INTERVAL_CONFIG = "user.cache.refresh.interval.ms";
+  private static final String USER_CACHE_REFRESH_INTERVAL_DOC = "How often to poll for new user registrations.";
+  private static final String USER_CACHE_REFRESH_INTERVAL_DISPLAY = "Refresh interval";
+  private static final Long USER_CACHE_REFRESH_INTERVAL_DEFAULT = 3600000L; // 1 hour
+
   private final TopicSelector topicSelector;
   private final PayloadToSourceRecordConverter payloadToSourceRecordConverter;
   private final RequestGenerator requestGenerator;
@@ -171,7 +181,36 @@ public static ConfigDef conf() {
             ++orderInGroup,
             Width.SHORT,
             REQUEST_GENERATOR_DISPLAY)
-        ;
+
+        .define(APPLICATION_LOOP_INTERVAL_CONFIG,
+            Type.LONG,
+            APPLICATION_LOOP_INTERVAL_DEFAULT,
+            Importance.LOW,
+            APPLICATION_LOOP_INTERVAL_DOC,
+            group,
+            ++orderInGroup,
+            Width.SHORT,
+            APPLICATION_LOOP_INTERVAL_DISPLAY)
+
+        .define(USER_CACHE_REFRESH_INTERVAL_CONFIG,
+            Type.LONG,
+            USER_CACHE_REFRESH_INTERVAL_DEFAULT,
+            Importance.LOW,
+            USER_CACHE_REFRESH_INTERVAL_DOC,
+            group,
+            ++orderInGroup,
+            Width.SHORT,
+            USER_CACHE_REFRESH_INTERVAL_DISPLAY
+
+        );
+  }
+
+  public Duration getApplicationLoopInterval() {
+    return Duration.ofMillis(this.getLong(APPLICATION_LOOP_INTERVAL_CONFIG));
+  }
+
+  public Duration getUserCacheRefreshInterval() {
+    return Duration.ofMillis(this.getLong(USER_CACHE_REFRESH_INTERVAL_CONFIG));
   }
 
   public Duration getPollInterval() {