diff --git a/pom.xml b/pom.xml
index b5e93dc..33772e3 100644
--- a/pom.xml
+++ b/pom.xml
@@ -135,6 +135,12 @@
             <artifactId>simpleclient_servlet</artifactId>
             <version>${prometheus.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <version>5.14.1</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
     <build>
         <plugins>
diff --git a/src/main/java/com/wire/bots/hold/DAO/MetadataDAO.java b/src/main/java/com/wire/bots/hold/DAO/MetadataDAO.java
new file mode 100644
index 0000000..933d83e
--- /dev/null
+++ b/src/main/java/com/wire/bots/hold/DAO/MetadataDAO.java
@@ -0,0 +1,20 @@
+package com.wire.bots.hold.DAO;
+
+import com.wire.bots.hold.model.Metadata;
+import org.jdbi.v3.sqlobject.config.RegisterColumnMapper;
+import org.jdbi.v3.sqlobject.customizer.Bind;
+import org.jdbi.v3.sqlobject.statement.SqlQuery;
+import org.jdbi.v3.sqlobject.statement.SqlUpdate;
+
+public interface MetadataDAO {
+    String FALLBACK_DOMAIN_KEY = "FALLBACK_DOMAIN_KEY";
+
+    @SqlUpdate("INSERT INTO Metadata (key, value)" +
+        "VALUES (:key, :value)" +
+        "ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value")
+    int insert(@Bind("key") String key, @Bind("value") String value);
+
+    @SqlQuery("SELECT key, value FROM Metadata WHERE key = :key LIMIT 1")
+    @RegisterColumnMapper(MetadataResultSetMapper.class)
+    Metadata get(@Bind("key") String key);
+}
diff --git a/src/main/java/com/wire/bots/hold/DAO/MetadataResultSetMapper.java b/src/main/java/com/wire/bots/hold/DAO/MetadataResultSetMapper.java
new file mode 100644
index 0000000..526985e
--- /dev/null
+++ b/src/main/java/com/wire/bots/hold/DAO/MetadataResultSetMapper.java
@@ -0,0 +1,19 @@
+package com.wire.bots.hold.DAO;
+
+import com.wire.bots.hold.model.Metadata;
+import org.jdbi.v3.core.mapper.ColumnMapper;
+import org.jdbi.v3.core.statement.StatementContext;
+
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+public class MetadataResultSetMapper implements ColumnMapper<Metadata> {
+
+    @Override
+    public Metadata map(ResultSet rs, int columnNumber, StatementContext ctx) throws SQLException {
+        return new Metadata(
+            rs.getString("key"),
+            rs.getString("value")
+        );
+    }
+}
diff --git a/src/main/java/com/wire/bots/hold/FallbackDomainFetcher.java b/src/main/java/com/wire/bots/hold/FallbackDomainFetcher.java
new file mode 100644
index 0000000..7c7f0fc
--- /dev/null
+++ b/src/main/java/com/wire/bots/hold/FallbackDomainFetcher.java
@@ -0,0 +1,69 @@
+package com.wire.bots.hold;
+
+import com.wire.bots.hold.DAO.MetadataDAO;
+import com.wire.bots.hold.model.Metadata;
+import com.wire.bots.hold.utils.Cache;
+import com.wire.helium.LoginClient;
+import com.wire.helium.models.BackendConfiguration;
+import com.wire.xenon.exceptions.HttpException;
+import com.wire.xenon.tools.Logger;
+
+import javax.ws.rs.ProcessingException;
+
+public class FallbackDomainFetcher implements Runnable {
+
+    private final LoginClient loginClient;
+    private final MetadataDAO metadataDAO;
+
+    /**
+     * Fetcher and handler for fallback domain.
+     * <p>
+     *     Fetches from API and compares against database value (if any), then inserts into database and updates cache value.
+     *     If value received from the API is different from what is saved in the database, a [RuntimeException] is thrown.
+     * </p>
+     * <p>
+     *     This fallback domain is necessary for LegalHold to work with Federation (as it needs id@domain) and not just the ID anymore.
+     *     In case there is a mismatch we are throwing a RuntimeException so it stops the execution of this app, so in an event
+     *     of already having a defined default domain saved in the database and this app restarts with a different domain
+     *     we don't get mismatching domains.
+     * </p>
+     * @param loginClient [{@link LoginClient}] as API to get backend configuration containing default domain.
+     * @param metadataDAO [{@link MetadataDAO}] as DAO to get/insert default domain to database.
+     *
+     * @throws RuntimeException if received domain from API is different from the one saved in the database.
+     */
+    FallbackDomainFetcher(LoginClient loginClient, MetadataDAO metadataDAO) {
+        this.loginClient = loginClient;
+        this.metadataDAO = metadataDAO;
+    }
+
+    @Override
+    public void run() {
+        if (Cache.getFallbackDomain() != null) { return; }
+
+        Metadata metadata = metadataDAO.get(MetadataDAO.FALLBACK_DOMAIN_KEY);
+        try {
+            BackendConfiguration apiVersionResponse = loginClient.getBackendConfiguration();
+
+            if (metadata == null) {
+                metadataDAO.insert(MetadataDAO.FALLBACK_DOMAIN_KEY, apiVersionResponse.domain);
+                Cache.setFallbackDomain(apiVersionResponse.domain);
+            } else {
+                if (metadata.value.equals(apiVersionResponse.domain)) {
+                    Cache.setFallbackDomain(apiVersionResponse.domain);
+                } else {
+                    String formattedExceptionMessage = String.format(
+                        "Database already has a default domain as %s and instead we got %s from the Backend API.",
+                        metadata.value,
+                        apiVersionResponse.domain
+                    );
+                    throw new RuntimeException(formattedExceptionMessage);
+                }
+            }
+        } catch (HttpException exception) {
+            Logger.exception(exception, "FallbackDomainFetcher.run, exception: %s", exception.getMessage());
+        } catch (ProcessingException pexception) {
+            Logger.info("FallbackDomainFetcher.run, ignoring test exceptions");
+        }
+    }
+}
diff --git a/src/main/java/com/wire/bots/hold/NotificationProcessor.java b/src/main/java/com/wire/bots/hold/NotificationProcessor.java
index 6a8bc86..b28534f 100644
--- a/src/main/java/com/wire/bots/hold/NotificationProcessor.java
+++ b/src/main/java/com/wire/bots/hold/NotificationProcessor.java
@@ -3,38 +3,34 @@
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.wire.bots.hold.DAO.AccessDAO;
-import com.wire.bots.hold.model.Notification;
-import com.wire.bots.hold.model.NotificationList;
 import com.wire.bots.hold.model.database.LHAccess;
+import com.wire.helium.API;
 import com.wire.helium.LoginClient;
 import com.wire.helium.models.Access;
+import com.wire.helium.models.Event;
+import com.wire.helium.models.NotificationList;
 import com.wire.xenon.backend.models.Payload;
 import com.wire.xenon.exceptions.AuthException;
 import com.wire.xenon.exceptions.HttpException;
 import com.wire.xenon.tools.Logger;
 
 import javax.ws.rs.client.Client;
-import javax.ws.rs.client.WebTarget;
 import javax.ws.rs.core.Cookie;
-import javax.ws.rs.core.HttpHeaders;
-import javax.ws.rs.core.MediaType;
-import javax.ws.rs.core.Response;
 import java.util.List;
 import java.util.UUID;
 import java.util.logging.Level;
 
 public class NotificationProcessor implements Runnable {
+    private static final int DEFAULT_NOTIFICATION_SIZE = 100;
+
     private final Client client;
     private final AccessDAO accessDAO;
     private final HoldMessageResource messageResource;
-    private final WebTarget api;
 
-    NotificationProcessor(Client client, AccessDAO accessDAO, Config config, HoldMessageResource messageResource) {
+    NotificationProcessor(Client client, AccessDAO accessDAO, HoldMessageResource messageResource) {
         this.client = client;
         this.accessDAO = accessDAO;
         this.messageResource = messageResource;
-
-        api = client.target(config.apiHost);
     }
 
     @Override
@@ -58,7 +54,10 @@ private Access getAccess(Cookie cookie) throws HttpException {
 
     private void process(LHAccess device) {
         UUID userId = device.userId;
+
         try {
+            final API api = new API(client, null, device.token);
+
             Logger.debug("`GET /notifications`: user: %s, last: %s", userId, device.last);
 
             String cookieValue = device.cookie;
@@ -76,39 +75,38 @@ private void process(LHAccess device) {
 
             device.token = access.getAccessToken();
 
-            NotificationList notificationList = retrieveNotifications(device);
+            NotificationList notificationList = api.retrieveNotifications(
+                device.clientId,
+                device.last,
+                DEFAULT_NOTIFICATION_SIZE
+            );
 
             process(userId, notificationList);
-
         } catch (AuthException e) {
             accessDAO.disable(userId);
             Logger.info("Disabled LH device for user: %s, error: %s", userId, e.getMessage());
+        } catch (HttpException e) {
+            Logger.exception(e, "NotificationProcessor: Couldn't retrieve notifications, error: %s", e.getMessage());
         } catch (Exception e) {
             Logger.exception(e, "NotificationProcessor: user: %s, last: %s, error: %s", userId, device.last, e.getMessage());
         }
     }
 
-    private static String bearer(String token) {
-        return token == null ? null : String.format("Bearer %s", token);
-    }
-
     private void process(UUID userId, NotificationList notificationList) {
-
-        for (Notification notif : notificationList.notifications) {
-            for (Payload payload : notif.payload) {
-                if (!process(userId, payload, notif.id)) {
-                    Logger.error("Failed to process: user: %s, notif: %s", userId, notif.id);
-                    //return;
+        for (Event event : notificationList.notifications) {
+            for (Payload payload : event.payload) {
+                if (!process(userId, payload, event.id)) {
+                    Logger.error("Failed to process: user: %s, event: %s", userId, event.id);
                 } else {
-                    Logger.debug("Processed: `%s` conv: %s, user: %s, notifId: %s",
+                    Logger.debug("Processed: `%s` conv: %s, user: %s, eventId: %s",
                             payload.type,
                             payload.conversation,
                             userId,
-                            notif.id);
+                            event.id);
                 }
             }
 
-            accessDAO.updateLast(userId, notif.id);
+            accessDAO.updateLast(userId, event.id);
         }
     }
 
@@ -122,13 +120,13 @@ private boolean process(UUID userId, Payload payload, UUID id) {
 
         if (payload.from == null || payload.data == null) return true;
 
-        final boolean b = messageResource.onNewMessage(userId, id, payload);
+        final boolean wasMessageSent = messageResource.onNewMessage(userId, id, payload);
 
-        if (!b) {
+        if (!wasMessageSent) {
             Logger.error("process: `%s` user: %s, from: %s:%s, error: %s", payload.type, userId, payload.from, payload.data.sender);
         }
 
-        return b;
+        return wasMessageSent;
     }
 
     private void trace(Payload payload) {
@@ -141,30 +139,4 @@ private void trace(Payload payload) {
             }
         }
     }
-
-    //TODO remove this and use retrieveNotifications provided by Helium
-    private NotificationList retrieveNotifications(LHAccess access) throws HttpException {
-        Response response = api.path("notifications").queryParam("client", access.clientId).queryParam("since", access.last).queryParam("size", 100).request(MediaType.APPLICATION_JSON).accept(MediaType.APPLICATION_JSON).header(HttpHeaders.AUTHORIZATION, bearer(access.token)).get();
-
-        int status = response.getStatus();
-
-        if (status == 200) {
-            return response.readEntity(NotificationList.class);
-        }
-
-        if (status == 404) {  //todo what???
-            return response.readEntity(NotificationList.class);
-        }
-
-        if (status == 401) {   //todo nginx returns text/html for 401. Cannot deserialize as json
-            response.readEntity(String.class);
-            throw new AuthException(status);
-        }
-
-        if (status == 403) {
-            throw response.readEntity(AuthException.class);
-        }
-
-        throw response.readEntity(HttpException.class);
-    }
 }
diff --git a/src/main/java/com/wire/bots/hold/Service.java b/src/main/java/com/wire/bots/hold/Service.java
index 67d3b3a..aa470cd 100644
--- a/src/main/java/com/wire/bots/hold/Service.java
+++ b/src/main/java/com/wire/bots/hold/Service.java
@@ -22,6 +22,7 @@
 import com.wire.bots.cryptobox.CryptoException;
 import com.wire.bots.hold.DAO.AccessDAO;
 import com.wire.bots.hold.DAO.EventsDAO;
+import com.wire.bots.hold.DAO.MetadataDAO;
 import com.wire.bots.hold.filters.ServiceAuthenticationFilter;
 import com.wire.bots.hold.healthchecks.SanityCheck;
 import com.wire.bots.hold.monitoring.RequestMdcFactoryFilter;
@@ -63,12 +64,13 @@
 
 import javax.ws.rs.client.Client;
 import java.util.UUID;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
 
 public class Service extends Application<Config> {
     public static Service instance;
     public static MetricRegistry metrics;
-    public static String API_DOMAIN;
     protected Config config;
     protected Environment environment;
     protected Jdbi jdbi;
@@ -101,7 +103,7 @@ protected SwaggerBundleConfiguration getSwaggerBundleConfiguration(Config config
     }
 
     @Override
-    public void run(Config config, Environment environment) {
+    public void run(Config config, Environment environment) throws ExecutionException, InterruptedException {
         this.config = config;
         this.environment = environment;
         Service.metrics = environment.metrics();
@@ -118,6 +120,7 @@ public void run(Config config, Environment environment) {
 
         final AccessDAO accessDAO = jdbi.onDemand(AccessDAO.class);
         final EventsDAO eventsDAO = jdbi.onDemand(EventsDAO.class);
+        final MetadataDAO metadataDAO = jdbi.onDemand(MetadataDAO.class);
 
         final DeviceManagementService deviceManagementService = new DeviceManagementService(accessDAO, cf);
 
@@ -142,13 +145,28 @@ public void run(Config config, Environment environment) {
 
         addResource(ServiceAuthenticationFilter.ServiceAuthenticationFeature.class);
 
-        environment.healthChecks().register("SanityCheck", new SanityCheck(accessDAO, httpClient));
+        final Future<?> fallbackDomainFetcher = environment
+            .lifecycle()
+            .executorService("fallback_domain_fetcher")
+            .build()
+            .submit(
+                new FallbackDomainFetcher(
+                    new LoginClient(httpClient),
+                    metadataDAO
+                )
+            );
+
+        fallbackDomainFetcher.get();
+
+        environment.healthChecks().register(
+            "SanityCheck",
+            new SanityCheck(accessDAO, httpClient)
+        );
 
         final HoldClientRepo repo = new HoldClientRepo(jdbi, cf, httpClient);
-        final LoginClient loginClient = new LoginClient(httpClient);
 
         final HoldMessageResource holdMessageResource = new HoldMessageResource(new MessageHandler(jdbi), repo);
-        final NotificationProcessor notificationProcessor = new NotificationProcessor(httpClient, accessDAO, config, holdMessageResource);
+        final NotificationProcessor notificationProcessor = new NotificationProcessor(httpClient, accessDAO, holdMessageResource);
 
         environment.lifecycle()
                 .scheduledExecutorService("notifications")
@@ -158,10 +176,6 @@ public void run(Config config, Environment environment) {
         CollectorRegistry.defaultRegistry.register(new DropwizardExports(metrics));
 
         environment.getApplicationContext().addServlet(MetricsServlet.class, "/metrics");
-
-        // todo here
-        // String res = loginClient.getBackendConfiguration();
-        // handle res ^
     }
 
     public Config getConfig() {
diff --git a/src/main/java/com/wire/bots/hold/healthchecks/SanityCheck.java b/src/main/java/com/wire/bots/hold/healthchecks/SanityCheck.java
index 0408aed..d6e6047 100644
--- a/src/main/java/com/wire/bots/hold/healthchecks/SanityCheck.java
+++ b/src/main/java/com/wire/bots/hold/healthchecks/SanityCheck.java
@@ -3,6 +3,7 @@
 import com.codahale.metrics.health.HealthCheck;
 import com.wire.bots.hold.DAO.AccessDAO;
 import com.wire.bots.hold.model.database.LHAccess;
+import com.wire.bots.hold.utils.Cache;
 import com.wire.helium.API;
 import com.wire.xenon.backend.models.QualifiedId;
 import com.wire.xenon.tools.Logger;
@@ -36,8 +37,10 @@ protected Result check() {
             while (!accessList.isEmpty()) {
                 Logger.info("SanityCheck: checking %d devices, created: %s", accessList.size(), created);
                 for (LHAccess access : accessList) {
+                    // TODO(WPB-11287): Use user domain if exists, otherwise default
+                    // TODO: String domain = (access.domain != null) ? access.domain : Cache.DEFAULT_DOMAIN;
                     boolean hasDevice = api.hasDevice(
-                        new QualifiedId(access.userId, null), // TODO(WPB-11287): Change null to default domain
+                        new QualifiedId(access.userId, Cache.getFallbackDomain()), // TODO(WPB-11287): Change null to default domain
                         access.clientId
                     );
 
diff --git a/src/main/java/com/wire/bots/hold/model/Metadata.java b/src/main/java/com/wire/bots/hold/model/Metadata.java
new file mode 100644
index 0000000..f145827
--- /dev/null
+++ b/src/main/java/com/wire/bots/hold/model/Metadata.java
@@ -0,0 +1,11 @@
+package com.wire.bots.hold.model;
+
+public class Metadata {
+    public String key;
+    public String value;
+
+    public Metadata(String key, String value) {
+        this.key = key;
+        this.value = value;
+    }
+}
diff --git a/src/main/java/com/wire/bots/hold/model/Notification.java b/src/main/java/com/wire/bots/hold/model/Notification.java
deleted file mode 100644
index 5bfba19..0000000
--- a/src/main/java/com/wire/bots/hold/model/Notification.java
+++ /dev/null
@@ -1,20 +0,0 @@
-package com.wire.bots.hold.model;
-
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
-import com.fasterxml.jackson.annotation.JsonProperty;
-import com.wire.xenon.backend.models.Payload;
-
-import javax.validation.constraints.NotNull;
-import java.util.List;
-import java.util.UUID;
-
-@JsonIgnoreProperties(ignoreUnknown = true)
-public class Notification {
-    @JsonProperty
-    @NotNull
-    public List<Payload> payload;
-
-    @JsonProperty
-    @NotNull
-    public UUID id;
-}
diff --git a/src/main/java/com/wire/bots/hold/model/NotificationList.java b/src/main/java/com/wire/bots/hold/model/NotificationList.java
deleted file mode 100644
index 76a31f8..0000000
--- a/src/main/java/com/wire/bots/hold/model/NotificationList.java
+++ /dev/null
@@ -1,18 +0,0 @@
-package com.wire.bots.hold.model;
-
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
-import com.fasterxml.jackson.annotation.JsonProperty;
-
-import javax.validation.constraints.NotNull;
-import java.util.ArrayList;
-
-@JsonIgnoreProperties(ignoreUnknown = true)
-public class NotificationList {
-    @JsonProperty("has_more")
-    @NotNull
-    public Boolean hasMore;
-
-    @JsonProperty
-    @NotNull
-    public ArrayList<Notification> notifications;
-}
diff --git a/src/main/java/com/wire/bots/hold/model/api/shared/ApiVersionResponse.java b/src/main/java/com/wire/bots/hold/model/api/shared/ApiVersionResponse.java
index 68328ee..5ede5ab 100644
--- a/src/main/java/com/wire/bots/hold/model/api/shared/ApiVersionResponse.java
+++ b/src/main/java/com/wire/bots/hold/model/api/shared/ApiVersionResponse.java
@@ -11,4 +11,4 @@ public class ApiVersionResponse {
     public ApiVersionResponse(List<Integer> supported) {
         this.supported = supported;
     }
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/wire/bots/hold/model/dto/InitializedDeviceDTO.java b/src/main/java/com/wire/bots/hold/model/dto/InitializedDeviceDTO.java
index 567062d..4266ec4 100644
--- a/src/main/java/com/wire/bots/hold/model/dto/InitializedDeviceDTO.java
+++ b/src/main/java/com/wire/bots/hold/model/dto/InitializedDeviceDTO.java
@@ -26,4 +26,4 @@ public PreKey getLastPreKey() {
     public String getFingerprint() {
         return fingerprint;
     }
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/wire/bots/hold/monitoring/ApiVersionResource.java b/src/main/java/com/wire/bots/hold/monitoring/ApiVersionResource.java
index 5a0c771..16f0dc9 100644
--- a/src/main/java/com/wire/bots/hold/monitoring/ApiVersionResource.java
+++ b/src/main/java/com/wire/bots/hold/monitoring/ApiVersionResource.java
@@ -39,7 +39,7 @@ public Response apiVersion() {
         ApiVersionResponse response = new ApiVersionResponse(List.of(0,1));
 
         return Response
-                .ok(response)
-                .build();
+            .ok(response)
+            .build();
     }
 }
diff --git a/src/main/java/com/wire/bots/hold/monitoring/StatusResource.java b/src/main/java/com/wire/bots/hold/monitoring/StatusResource.java
index 724fee7..c44e87d 100644
--- a/src/main/java/com/wire/bots/hold/monitoring/StatusResource.java
+++ b/src/main/java/com/wire/bots/hold/monitoring/StatusResource.java
@@ -35,7 +35,7 @@ public class StatusResource {
     @ApiOperation(value = "Status")
     public Response statusEmpty() {
         return Response
-                .ok()
-                .build();
+            .ok()
+            .build();
     }
 }
diff --git a/src/main/java/com/wire/bots/hold/resource/v0/audit/ConversationResource.java b/src/main/java/com/wire/bots/hold/resource/v0/audit/ConversationResource.java
index a95e697..7637839 100644
--- a/src/main/java/com/wire/bots/hold/resource/v0/audit/ConversationResource.java
+++ b/src/main/java/com/wire/bots/hold/resource/v0/audit/ConversationResource.java
@@ -67,6 +67,8 @@ public Response list(@ApiParam @PathParam("conversationId") UUID conversationId,
         try {
             List<Event> events = eventsDAO.listAllAsc(conversationId);
 
+            // TODO(WPB-11287) Verify default domain
+
             testAPI();
 
             Cache cache = new Cache(api, assetsDAO);
diff --git a/src/main/java/com/wire/bots/hold/resource/v0/backend/ConfirmResourceV0.java b/src/main/java/com/wire/bots/hold/resource/v0/backend/ConfirmResourceV0.java
index 6d82c84..0f91e83 100644
--- a/src/main/java/com/wire/bots/hold/resource/v0/backend/ConfirmResourceV0.java
+++ b/src/main/java/com/wire/bots/hold/resource/v0/backend/ConfirmResourceV0.java
@@ -29,9 +29,9 @@ public ConfirmResourceV0(DeviceManagementService deviceManagementService) {
     @ServiceAuthorization
     @ApiOperation(value = "Confirm legal hold device")
     @ApiResponses(value = {
-            @ApiResponse(code = 400, message = "Bad request. Invalid Payload"),
-            @ApiResponse(code = 500, message = "Something went wrong"),
-            @ApiResponse(code = 200, message = "Legal Hold Device enabled")})
+        @ApiResponse(code = 400, message = "Bad request. Invalid Payload"),
+        @ApiResponse(code = 500, message = "Something went wrong"),
+        @ApiResponse(code = 200, message = "Legal Hold Device enabled")})
     public Response confirm(@ApiParam @Valid @NotNull ConfirmPayloadV0 payload) {
         try {
             deviceManagementService.confirmDevice(
@@ -52,6 +52,4 @@ public Response confirm(@ApiParam @Valid @NotNull ConfirmPayloadV0 payload) {
                 .build();
         }
     }
-
-
 }
diff --git a/src/main/java/com/wire/bots/hold/resource/v0/backend/InitiateResourceV0.java b/src/main/java/com/wire/bots/hold/resource/v0/backend/InitiateResourceV0.java
index 6f444f4..38dfcb9 100644
--- a/src/main/java/com/wire/bots/hold/resource/v0/backend/InitiateResourceV0.java
+++ b/src/main/java/com/wire/bots/hold/resource/v0/backend/InitiateResourceV0.java
@@ -31,9 +31,9 @@ public InitiateResourceV0(DeviceManagementService deviceManagementService) {
     @ServiceAuthorization
     @ApiOperation(value = "Initiate", response = InitResponse.class)
     @ApiResponses(value = {
-            @ApiResponse(code = 400, message = "Bad request. Invalid Payload"),
-            @ApiResponse(code = 500, message = "Something went wrong"),
-            @ApiResponse(code = 200, message = "CryptoBox initiated")})
+        @ApiResponse(code = 400, message = "Bad request. Invalid Payload"),
+        @ApiResponse(code = 500, message = "Something went wrong"),
+        @ApiResponse(code = 200, message = "CryptoBox initiated")})
     public Response initiate(@ApiParam @Valid @NotNull InitPayloadV0 init) {
         try {
             final InitializedDeviceDTO initializedDeviceDTO =
diff --git a/src/main/java/com/wire/bots/hold/resource/v0/backend/RemoveResourceV0.java b/src/main/java/com/wire/bots/hold/resource/v0/backend/RemoveResourceV0.java
index 805c6b6..7068233 100644
--- a/src/main/java/com/wire/bots/hold/resource/v0/backend/RemoveResourceV0.java
+++ b/src/main/java/com/wire/bots/hold/resource/v0/backend/RemoveResourceV0.java
@@ -28,9 +28,9 @@ public RemoveResourceV0(DeviceManagementService deviceManagementService) {
     @ServiceAuthorization
     @ApiOperation(value = "Remove legal hold device")
     @ApiResponses(value = {
-            @ApiResponse(code = 400, message = "Bad request. Invalid Payload"),
-            @ApiResponse(code = 500, message = "Something went wrong"),
-            @ApiResponse(code = 200, message = "Legal Hold Device was removed")})
+        @ApiResponse(code = 400, message = "Bad request. Invalid Payload"),
+        @ApiResponse(code = 500, message = "Something went wrong"),
+        @ApiResponse(code = 200, message = "Legal Hold Device was removed")})
     public Response remove(@ApiParam @Valid InitPayloadV0 payload) {
         try {
             deviceManagementService.removeDevice(
diff --git a/src/main/java/com/wire/bots/hold/resource/v1/backend/ConfirmResourceV1.java b/src/main/java/com/wire/bots/hold/resource/v1/backend/ConfirmResourceV1.java
index 7395785..a32883d 100644
--- a/src/main/java/com/wire/bots/hold/resource/v1/backend/ConfirmResourceV1.java
+++ b/src/main/java/com/wire/bots/hold/resource/v1/backend/ConfirmResourceV1.java
@@ -28,9 +28,9 @@ public ConfirmResourceV1(DeviceManagementService deviceManagementService) {
     @ServiceAuthorization
     @ApiOperation(value = "Confirm legal hold device")
     @ApiResponses(value = {
-            @ApiResponse(code = 400, message = "Bad request. Invalid Payload"),
-            @ApiResponse(code = 500, message = "Something went wrong"),
-            @ApiResponse(code = 200, message = "Legal Hold Device enabled")})
+        @ApiResponse(code = 400, message = "Bad request. Invalid Payload"),
+        @ApiResponse(code = 500, message = "Something went wrong"),
+        @ApiResponse(code = 200, message = "Legal Hold Device enabled")})
     public Response confirm(@ApiParam @Valid @NotNull ConfirmPayloadV1 payload) {
         try {
             deviceManagementService.confirmDevice(
diff --git a/src/main/java/com/wire/bots/hold/resource/v1/backend/RemoveResourceV1.java b/src/main/java/com/wire/bots/hold/resource/v1/backend/RemoveResourceV1.java
index e70bd34..d38ebb9 100644
--- a/src/main/java/com/wire/bots/hold/resource/v1/backend/RemoveResourceV1.java
+++ b/src/main/java/com/wire/bots/hold/resource/v1/backend/RemoveResourceV1.java
@@ -27,9 +27,9 @@ public RemoveResourceV1(DeviceManagementService deviceManagementService) {
     @ServiceAuthorization
     @ApiOperation(value = "Remove legal hold device")
     @ApiResponses(value = {
-            @ApiResponse(code = 400, message = "Bad request. Invalid Payload"),
-            @ApiResponse(code = 500, message = "Something went wrong"),
-            @ApiResponse(code = 200, message = "Legal Hold Device was removed")})
+        @ApiResponse(code = 400, message = "Bad request. Invalid Payload"),
+        @ApiResponse(code = 500, message = "Something went wrong"),
+        @ApiResponse(code = 200, message = "Legal Hold Device was removed")})
     public Response remove(@ApiParam @Valid InitPayloadV1 payload) {
         try {
             deviceManagementService.removeDevice(payload.userId, payload.teamId);
@@ -44,6 +44,4 @@ public Response remove(@ApiParam @Valid InitPayloadV1 payload) {
                 .build();
         }
     }
-
-
 }
diff --git a/src/main/java/com/wire/bots/hold/utils/Cache.java b/src/main/java/com/wire/bots/hold/utils/Cache.java
index e0e55c2..95b4ee4 100644
--- a/src/main/java/com/wire/bots/hold/utils/Cache.java
+++ b/src/main/java/com/wire/bots/hold/utils/Cache.java
@@ -13,10 +13,11 @@
 import java.util.concurrent.ConcurrentHashMap;
 
 public class Cache {
-    // TODO(WPB-11287): Add default domain here
-    private static final ConcurrentHashMap<UUID, File> assets = new ConcurrentHashMap<>();//<messageId, File>
-    private static final ConcurrentHashMap<QualifiedId, User> users = new ConcurrentHashMap<>();//<userId, User>
-    private static final ConcurrentHashMap<QualifiedId, File> profiles = new ConcurrentHashMap<>();//<userId, Picture>
+    private static String FALLBACK_DOMAIN = null;
+
+    private static final ConcurrentHashMap<UUID, File> assets = new ConcurrentHashMap<>(); // <messageId, File>
+    private static final ConcurrentHashMap<QualifiedId, User> users = new ConcurrentHashMap<>(); // <QualifiedId, User>
+    private static final ConcurrentHashMap<QualifiedId, File> profiles = new ConcurrentHashMap<>(); // <QualifiedId, Picture>
     private final API api;
     private final AssetsDAO assetsDAO;
 
@@ -25,6 +26,14 @@ public Cache(API api, AssetsDAO assetsDAO) {
         this.assetsDAO = assetsDAO;
     }
 
+    public static void setFallbackDomain(String domain) {
+            FALLBACK_DOMAIN = domain;
+    }
+
+    public static String getFallbackDomain() {
+        return FALLBACK_DOMAIN;
+    }
+
     @Nullable
     public File getAssetFile(UUID messageId) {
 
@@ -57,7 +66,6 @@ public File getProfileImage(User user) {
     }
 
     public User getUser(QualifiedId userId) {
-        // TODO(WPB-11287): Fetch first in map then check API
         return users.computeIfAbsent(userId, k -> {
             try {
                 return api.getUser(userId);
diff --git a/src/main/resources/db/migration/V107__add_metadata_table.sql b/src/main/resources/db/migration/V107__add_metadata_table.sql
new file mode 100644
index 0000000..ef255d4
--- /dev/null
+++ b/src/main/resources/db/migration/V107__add_metadata_table.sql
@@ -0,0 +1,4 @@
+CREATE TABLE Metadata (
+    key VARCHAR(255) PRIMARY KEY,
+    value VARCHAR(255) NOT NULL
+);
diff --git a/src/test/java/com/wire/bots/hold/ConfirmRemoveResourceV1Test.java b/src/test/java/com/wire/bots/hold/ConfirmRemoveResourceV1Test.java
index 08ed44b..41474f1 100644
--- a/src/test/java/com/wire/bots/hold/ConfirmRemoveResourceV1Test.java
+++ b/src/test/java/com/wire/bots/hold/ConfirmRemoveResourceV1Test.java
@@ -24,7 +24,8 @@ public class ConfirmRemoveResourceV1Test {
     private static final String TOKEN = "dummy";
     private static final DropwizardTestSupport<Config> SUPPORT = new DropwizardTestSupport<>(
         Service.class, "hold.yaml",
-        ConfigOverride.config("token", TOKEN));
+        ConfigOverride.config("token", TOKEN),
+        ConfigOverride.config("apiHost", "dummy"));
     private static Client client;
     private static AccessDAO accessDAO;
 
diff --git a/src/test/java/com/wire/bots/hold/DatabaseTest.java b/src/test/java/com/wire/bots/hold/DatabaseTest.java
index 684239e..3bb7f88 100644
--- a/src/test/java/com/wire/bots/hold/DatabaseTest.java
+++ b/src/test/java/com/wire/bots/hold/DatabaseTest.java
@@ -5,6 +5,8 @@
 import com.wire.bots.hold.DAO.AccessDAO;
 import com.wire.bots.hold.DAO.AssetsDAO;
 import com.wire.bots.hold.DAO.EventsDAO;
+import com.wire.bots.hold.DAO.MetadataDAO;
+import com.wire.bots.hold.model.Metadata;
 import com.wire.bots.hold.model.database.Event;
 import com.wire.bots.hold.model.database.LHAccess;
 import com.wire.xenon.backend.models.QualifiedId;
@@ -19,13 +21,15 @@
 
 public class DatabaseTest {
     private static final DropwizardTestSupport<Config> SUPPORT = new DropwizardTestSupport<>(
-            Service.class, "hold.yaml",
-            ConfigOverride.config("token", "dummy"));
+        Service.class, "hold.yaml",
+        ConfigOverride.config("token", "dummy"),
+        ConfigOverride.config("apiHost", "dummy"));
 
     private static final ObjectMapper mapper = new ObjectMapper();
     private static AssetsDAO assetsDAO;
     private static EventsDAO eventsDAO;
     private static AccessDAO accessDAO;
+    private static MetadataDAO metadataDAO;
 
     @BeforeClass
     public static void init() throws Exception {
@@ -35,6 +39,7 @@ public static void init() throws Exception {
         eventsDAO = app.getJdbi().onDemand(EventsDAO.class);
         assetsDAO = app.getJdbi().onDemand(AssetsDAO.class);
         accessDAO = app.getJdbi().onDemand(AccessDAO.class);
+        metadataDAO = app.getJdbi().onDemand(MetadataDAO.class);
     }
 
     @AfterClass
@@ -114,4 +119,18 @@ public void accessTests() {
         assert lhAccess2 != null;
         assert lhAccess2.created.equals(lhAccess.created);
     }
+
+    @Test
+    public void metadataTests() {
+        String dummyKey = MetadataDAO.FALLBACK_DOMAIN_KEY + UUID.randomUUID();
+
+        Metadata nullMetadata = metadataDAO.get(dummyKey);
+        assert nullMetadata == null;
+
+        int insert = metadataDAO.insert(dummyKey, "dummy_domain");
+        Metadata metadata =  metadataDAO.get(dummyKey);
+
+        assert metadata != null;
+        assert metadata.value.equals("dummy_domain");
+    }
 }
diff --git a/src/test/java/com/wire/bots/hold/FallbackDomainFetcherTest.java b/src/test/java/com/wire/bots/hold/FallbackDomainFetcherTest.java
new file mode 100644
index 0000000..d35a8b2
--- /dev/null
+++ b/src/test/java/com/wire/bots/hold/FallbackDomainFetcherTest.java
@@ -0,0 +1,99 @@
+package com.wire.bots.hold;
+
+import com.wire.bots.hold.DAO.MetadataDAO;
+import com.wire.bots.hold.model.Metadata;
+import com.wire.bots.hold.utils.Cache;
+import com.wire.helium.LoginClient;
+import com.wire.helium.models.BackendConfiguration;
+import com.wire.xenon.exceptions.HttpException;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.*;
+
+public class FallbackDomainFetcherTest {
+
+    private MetadataDAO metadataDAO;
+    private LoginClient loginClient;
+    private FallbackDomainFetcher fallbackDomainFetcher;
+
+    @Before
+    public void before() {
+        // Clears cached domain
+        Cache.setFallbackDomain(null);
+        metadataDAO = mock(MetadataDAO.class);
+        loginClient = mock(LoginClient.class);
+        fallbackDomainFetcher = new FallbackDomainFetcher(loginClient, metadataDAO);
+    }
+
+    @After
+    public void after() {
+        // Clears cached domain
+        Cache.setFallbackDomain(null);
+    }
+
+    @Test
+    public void givenNoFallbackDomainInCacheAndDatabase_whenExecuting_thenFetchFromApiAndStoreInCacheAndDatabase() throws HttpException {
+        // given
+        BackendConfiguration backendConfiguration = new BackendConfiguration();
+        backendConfiguration.domain = "dummy_domain_3";
+
+        when(metadataDAO.get(MetadataDAO.FALLBACK_DOMAIN_KEY)).thenReturn(null);
+        when(metadataDAO.insert(any(), any())).thenReturn(1);
+        when(loginClient.getBackendConfiguration()).thenReturn(backendConfiguration);
+
+        // when
+        fallbackDomainFetcher.run();
+
+        // then
+        assert Cache.getFallbackDomain().equals("dummy_domain_3");
+        verify(metadataDAO, times(1)).insert(MetadataDAO.FALLBACK_DOMAIN_KEY, backendConfiguration.domain);
+    }
+
+    @Test
+    public void givenNoFallbackDomainInCache_whenExecuting_thenFetchFromAPIAndCompareWithDatabase() throws HttpException {
+        // given
+        BackendConfiguration backendConfiguration = new BackendConfiguration();
+        backendConfiguration.domain = "dummy_domain_2";
+
+        Metadata metadata = new Metadata(MetadataDAO.FALLBACK_DOMAIN_KEY, "dummy_domain_2");
+
+        when(metadataDAO.get(MetadataDAO.FALLBACK_DOMAIN_KEY)).thenReturn(metadata);
+        when(loginClient.getBackendConfiguration()).thenReturn(backendConfiguration);
+
+        // when
+        fallbackDomainFetcher.run();
+
+        // then
+        assert Cache.getFallbackDomain().equals("dummy_domain_2");
+    }
+
+    @Test(expected=RuntimeException.class)
+    public void givenNoFallbackDomainInCache_whenExecutingAndApiReturnsDifferentDomainFromDatabase_thenThrowRuntimeException() throws HttpException, RuntimeException {
+        // given
+        BackendConfiguration backendConfiguration = new BackendConfiguration();
+        backendConfiguration.domain = "dummy_domain_1";
+
+        Metadata metadata = new Metadata(MetadataDAO.FALLBACK_DOMAIN_KEY, "dummy_domain_2");
+
+        when(metadataDAO.get(MetadataDAO.FALLBACK_DOMAIN_KEY)).thenReturn(metadata);
+        when(loginClient.getBackendConfiguration()).thenReturn(backendConfiguration);
+
+        // when
+        fallbackDomainFetcher.run();
+    }
+
+    @Test
+    public void givenFallbackDomainInCache_whenExecuting_thenReturnAndIgnoreDatabaseAndApiCalls() {
+        // given
+        Cache.setFallbackDomain("dummy_domain_0");
+
+        // when
+        fallbackDomainFetcher.run();
+
+        // then
+        assert Cache.getFallbackDomain().equals("dummy_domain_0");
+    }
+}
diff --git a/src/test/java/com/wire/bots/hold/InitiateResourceV1Test.java b/src/test/java/com/wire/bots/hold/InitiateResourceV1Test.java
index 1dbe8ad..33d754c 100644
--- a/src/test/java/com/wire/bots/hold/InitiateResourceV1Test.java
+++ b/src/test/java/com/wire/bots/hold/InitiateResourceV1Test.java
@@ -22,7 +22,8 @@ public class InitiateResourceV1Test {
     private static final String TOKEN = "dummy";
     private static final DropwizardTestSupport<Config> SUPPORT = new DropwizardTestSupport<>(
         Service.class, "hold.yaml",
-        ConfigOverride.config("token", TOKEN));
+        ConfigOverride.config("token", TOKEN),
+        ConfigOverride.config("apiHost", "dummy"));
     private static Client client;
 
     @BeforeClass
diff --git a/src/test/java/com/wire/bots/hold/utils/CacheTest.java b/src/test/java/com/wire/bots/hold/utils/CacheTest.java
new file mode 100644
index 0000000..ddbf2dd
--- /dev/null
+++ b/src/test/java/com/wire/bots/hold/utils/CacheTest.java
@@ -0,0 +1,38 @@
+package com.wire.bots.hold.utils;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class CacheTest {
+
+    @Before
+    public void before() {
+        // Clears cached domain
+        Cache.setFallbackDomain(null);
+    }
+
+    @After
+    public void after() {
+        // Clears cached domain
+        Cache.setFallbackDomain(null);
+    }
+
+    @Test
+    public void verifyDefaultDomainIsSetCorrectly() {
+        String firstDomain = Cache.getFallbackDomain();
+        assert firstDomain == null;
+
+        Cache.setFallbackDomain("dummy_domain");
+        String secondDomain = Cache.getFallbackDomain();
+
+        assert secondDomain != null;
+        assert secondDomain.equals("dummy_domain");
+
+        Cache.setFallbackDomain("dummy_domain_3");
+        String thirdDomain = Cache.getFallbackDomain();
+
+        assert thirdDomain != null;
+        assert thirdDomain.equals("dummy_domain_3");
+    }
+}