diff --git a/backend/src/apis/openai/OpenaiClient.ts b/backend/src/apis/openai/OpenaiClient.ts
index eb37a04f8..5655020aa 100644
--- a/backend/src/apis/openai/OpenaiClient.ts
+++ b/backend/src/apis/openai/OpenaiClient.ts
@@ -92,6 +92,7 @@ export class OpenaiClient {
     if (openaiThreadEntity.updatedAt < new Date(Date.now() - OPENAI_AI_THREAD_DEFAULT_TIMEOUT_DAYS * 24 * 60 * 60 * 1000)) {
       logger.info(`Openai thread for user: ${user.id} is older than ${OPENAI_AI_THREAD_DEFAULT_TIMEOUT_DAYS} days, deleting...`)
       // let run async, because it could need some time, but we don't need to wait, because we create a new one nevertheless
+      // biome-ignore lint/complexity/noVoid: start it intentionally async without waiting for result
       void this.deleteThread(openaiThreadEntity.id)
       return []
     }
diff --git a/backend/src/graphql/resolver/TransactionResolver.test.ts b/backend/src/graphql/resolver/TransactionResolver.test.ts
index 774502b28..636c4d63f 100644
--- a/backend/src/graphql/resolver/TransactionResolver.test.ts
+++ b/backend/src/graphql/resolver/TransactionResolver.test.ts
@@ -73,7 +73,6 @@ let peter: User
 
 let homeCom: DbCommunity
 let foreignCom: DbCommunity
-let fedForeignCom: DbFederatedCommunity
 
 describe('send coins', () => {
   beforeAll(async () => {
diff --git a/backend/src/seeds/factory/user.ts b/backend/src/seeds/factory/user.ts
index 44db02c8f..36d9adfeb 100644
--- a/backend/src/seeds/factory/user.ts
+++ b/backend/src/seeds/factory/user.ts
@@ -18,7 +18,6 @@ export const userFactory = async (
   // console.log('call createUser with', JSON.stringify(user, null, 2))
   const response = await mutate({ mutation: createUser, variables: user })
   if (!response?.data?.createUser) {
-    // biome-ignore lint/suspicious/noConsole: will be used in tests where logging is mocked
     // console.log(JSON.stringify(response, null, 2))
     throw new Error('createUser mutation returned unexpected response')
   }
diff --git a/config-schema/src/validate.ts b/config-schema/src/validate.ts
index 83cf097b3..17ccea483 100644
--- a/config-schema/src/validate.ts
+++ b/config-schema/src/validate.ts
@@ -31,6 +31,7 @@ export function validate(schema: ObjectSchema, data: any) {
             )
           }
       } catch (e) {
+        // biome-ignore lint/suspicious/noConsole: schema validation may be run before logger is initialized
         console.error('Error getting description for key ' + key + ': ' + e)
         throw e
       }
diff --git a/core/src/graphql/logic/storeLinkAsRedeemed.ts b/core/src/graphql/logic/storeLinkAsRedeemed.ts
index cccc97d50..efc3589de 100644
--- a/core/src/graphql/logic/storeLinkAsRedeemed.ts
+++ b/core/src/graphql/logic/storeLinkAsRedeemed.ts
@@ -1,4 +1,8 @@
-import { TransactionLink as DbTransactionLink, User as DbUser } from "database";
+import { TransactionLink as DbTransactionLink, User as DbUser } from 'database'
+import { getLogger } from 'log4js'
+import { LOG4JS_BASE_CATEGORY_NAME } from '../../config/const'
+
+const logger = getLogger(`${LOG4JS_BASE_CATEGORY_NAME}.graphql.logic.storeLinkAsRedeemed`)
 
 export async function storeLinkAsRedeemed(
     dbTransactionLink: DbTransactionLink,
@@ -11,7 +15,7 @@ export async function storeLinkAsRedeemed(
         await DbTransactionLink.save(dbTransactionLink)
         return true
     } catch (err) {
-        console.error('error in storeLinkAsRedeemed;', err)
+        logger.error('error: ', err)
         return false
     }
 }
\ No newline at end of file
diff --git a/core/src/types/images.d.ts b/core/src/types/images.d.ts
index ef7006d32..91c6fd6f9 100644
--- a/core/src/types/images.d.ts
+++ b/core/src/types/images.d.ts
@@ -1,3 +1,4 @@
+// biome-ignore lint/style/noDefaultExport: Asset modules use default export by convention
 declare module '*.jpg' {
   const value: string
   export default value
diff --git a/database/src/queries/communityHandshakes.test.ts b/database/src/queries/communityHandshakes.test.ts
index 09937cc66..c1b665bab 100644
--- a/database/src/queries/communityHandshakes.test.ts
+++ b/database/src/queries/communityHandshakes.test.ts
@@ -58,7 +58,6 @@ describe('communityHandshakes', () => {
     communityHandshakeState!.status = CommunityHandshakeStateType.START_OPEN_CONNECTION_CALLBACK    
     await communityHandshakeState!.save()
     const communityHandshakeState2 = await findPendingCommunityHandshake(publicKey, '1_0')
-    const states = await DbCommunityHandshakeState.find()
     expect(communityHandshakeState2).toBeDefined()
     expect(communityHandshakeState2).toMatchObject({
       publicKey: publicKey.asBuffer(),
diff --git a/federation/src/graphql/api/1_0/resolver/AuthenticationResolver.ts b/federation/src/graphql/api/1_0/resolver/AuthenticationResolver.ts
index d22c816ff..3bee91e3e 100644
--- a/federation/src/graphql/api/1_0/resolver/AuthenticationResolver.ts
+++ b/federation/src/graphql/api/1_0/resolver/AuthenticationResolver.ts
@@ -62,6 +62,7 @@ export class AuthenticationResolver {
 
       // no await to respond immediately and invoke callback-request asynchronously
       // important: startOpenConnectionCallback must catch all exceptions them self, or server will crash!
+      // biome-ignore lint/complexity/noVoid: start it intentionally async without waiting for result
       void startOpenConnectionCallback(args.handshakeID, argsPublicKey, fedComA)
       methodLogger.debug('openConnection() successfully initiated callback and returns true immediately...')
       return true
@@ -96,6 +97,7 @@ export class AuthenticationResolver {
         `found fedComB and start authentication: ${fedComB.endPoint}${fedComB.apiVersion}`,
       )
       // no await to respond immediately and invoke authenticate-request asynchronously
+      // biome-ignore lint/complexity/noVoid: start it intentionally async without waiting for result
       void startAuthentication(args.handshakeID, openConnectionCallbackJwtPayload.oneTimeCode, fedComB)
       // methodLogger.debug('openConnectionCallback() successfully initiated authentication and returns true immediately...')
       return true
diff --git a/federation/src/server/cors.ts b/federation/src/server/cors.ts
index 873d6a2eb..95663695d 100644
--- a/federation/src/server/cors.ts
+++ b/federation/src/server/cors.ts
@@ -1,9 +1,8 @@
-import cors from 'cors'
+import corsLib from 'cors'
 
 const corsOptions = {
   origin: '*',
   exposedHeaders: ['token'],
 }
 
-// biome-ignore lint/style/noDefaultExport: <explanation>
-export default cors(corsOptions)
+export const cors = corsLib(corsOptions)
diff --git a/shared/src/helper/onShutdown.ts b/shared/src/helper/onShutdown.ts
index a27c931a6..ea24bf2fc 100644
--- a/shared/src/helper/onShutdown.ts
+++ b/shared/src/helper/onShutdown.ts
@@ -1,4 +1,3 @@
-import { Logger } from 'log4js'
 import colors from 'yoctocolors-cjs'
 
 export enum ShutdownReason {
@@ -44,8 +43,10 @@ export function onShutdown(shutdownHandler: (reason: ShutdownReason, error?: Err
 }
 
 export function printServerCrashAsciiArt(msg1: string, msg2: string, msg3: string) {
+  // biome-ignore-start lint/suspicious/noConsole: Server Crash Ascii Art is for console and stdout
   console.error(colors.redBright(` /\\_/\\ ${msg1}`))
   console.error(colors.redBright(`( x.x )  ${msg2}`))
   console.error(colors.redBright(` >   <   ${msg3}`))
   console.error(colors.redBright(''))
+  // biome-ignore-end lint/suspicious/noConsole: Server Crash Ascii Art is for console and stdout
 }
\ No newline at end of file