diff --git a/backend/src/controllers/assignments.ts b/backend/src/controllers/assignments.ts
index 296de160..2ecb35cb 100644
--- a/backend/src/controllers/assignments.ts
+++ b/backend/src/controllers/assignments.ts
@@ -66,7 +66,7 @@ export async function putAssignmentHandler(req: Request, res: Response): Promise
     res.json({ assignment });
 }
 
-export async function deleteAssignmentHandler(req: Request, res: Response): Promise<void> {
+export async function deleteAssignmentHandler(req: Request, _res: Response): Promise<void> {
     const id = Number(req.params.id);
     const classid = req.params.classid;
     requireFields({ id, classid });
@@ -75,7 +75,7 @@ export async function deleteAssignmentHandler(req: Request, res: Response): Prom
         throw new BadRequestException('Assignment id should be a number');
     }
 
-    const assignment = await deleteAssignment(classid, id);
+    await deleteAssignment(classid, id);
 }
 
 export async function getAssignmentsSubmissionsHandler(req: Request, res: Response): Promise<void> {
diff --git a/backend/src/controllers/groups.ts b/backend/src/controllers/groups.ts
index 85b0809c..ec177dcc 100644
--- a/backend/src/controllers/groups.ts
+++ b/backend/src/controllers/groups.ts
@@ -3,11 +3,10 @@ import { createGroup, deleteGroup, getAllGroups, getGroup, getGroupSubmissions,
 import { GroupDTO } from '@dwengo-1/common/interfaces/group';
 import { requireFields } from './error-helper.js';
 import { BadRequestException } from '../exceptions/bad-request-exception.js';
-import { getLogger } from '../logging/initalize.js';
 import { EntityDTO } from '@mikro-orm/core';
 import { Group } from '../entities/assignments/group.entity.js';
 
-function checkGroupFields(classId: any, assignmentId: any, groupId: any) {
+function checkGroupFields(classId: string, assignmentId: number, groupId: number): void {
     requireFields({ classId, assignmentId, groupId });
 
     if (isNaN(assignmentId)) {
diff --git a/backend/src/controllers/submissions.ts b/backend/src/controllers/submissions.ts
index a742685f..fb681656 100644
--- a/backend/src/controllers/submissions.ts
+++ b/backend/src/controllers/submissions.ts
@@ -1,7 +1,6 @@
 import { Request, Response } from 'express';
 import { createSubmission, deleteSubmission, getAllSubmissions, getSubmission } from '../services/submissions.js';
 import { BadRequestException } from '../exceptions/bad-request-exception.js';
-import { NotFoundException } from '../exceptions/not-found-exception.js';
 import { LearningObjectIdentifier } from '../entities/content/learning-object-identifier.js';
 import { Language, languageMap } from '@dwengo-1/common/util/language';
 import { SubmissionDTO } from '@dwengo-1/common/interfaces/submission';
diff --git a/backend/src/interfaces/assignment.ts b/backend/src/interfaces/assignment.ts
index 2e591797..7abb3d3c 100644
--- a/backend/src/interfaces/assignment.ts
+++ b/backend/src/interfaces/assignment.ts
@@ -4,7 +4,6 @@ import { Assignment } from '../entities/assignments/assignment.entity.js';
 import { Class } from '../entities/classes/class.entity.js';
 import { getLogger } from '../logging/initalize.js';
 import { AssignmentDTO } from '@dwengo-1/common/interfaces/assignment';
-import { mapToGroupDTO } from './group.js';
 
 export function mapToAssignmentDTOId(assignment: Assignment): AssignmentDTO {
     return {
diff --git a/backend/src/services/assignments.ts b/backend/src/services/assignments.ts
index 55f4947c..1b8fc9f1 100644
--- a/backend/src/services/assignments.ts
+++ b/backend/src/services/assignments.ts
@@ -14,9 +14,7 @@ import { mapToSubmissionDTO, mapToSubmissionDTOId } from '../interfaces/submissi
 import { fetchClass } from './classes.js';
 import { QuestionDTO, QuestionId } from '@dwengo-1/common/interfaces/question';
 import { SubmissionDTO, SubmissionDTOId } from '@dwengo-1/common/interfaces/submission';
-import { getLogger } from '../logging/initalize.js';
-import { EntityData, EntityDTO, FromEntityType } from '@mikro-orm/core';
-import { DwengoEntityRepository } from '../data/dwengo-entity-repository.js';
+import { EntityDTO } from '@mikro-orm/core';
 import { putObject } from './service-helper.js';
 
 export async function fetchAssignment(classid: string, assignmentNumber: number): Promise<Assignment> {
@@ -24,7 +22,7 @@ export async function fetchAssignment(classid: string, assignmentNumber: number)
     const cls = await classRepository.findById(classid);
 
     if (!cls) {
-        throw new NotFoundException("Could not find assignment's class");
+        throw new NotFoundException('Could not find assignment\'s class');
     }
 
     const assignmentRepository = getAssignmentRepository();
@@ -88,7 +86,7 @@ export async function deleteAssignment(classid: string, id: number): Promise<Ass
 export async function getAssignmentsSubmissions(
     classid: string,
     assignmentNumber: number,
-    full: boolean
+    full: boolean,
 ): Promise<SubmissionDTO[] | SubmissionDTOId[]> {
     const assignment = await fetchAssignment(classid, assignmentNumber);
 
diff --git a/backend/src/services/groups.ts b/backend/src/services/groups.ts
index 9b9903ed..f52fff29 100644
--- a/backend/src/services/groups.ts
+++ b/backend/src/services/groups.ts
@@ -1,21 +1,12 @@
-import { assign, EntityDTO } from '@mikro-orm/core';
-import {
-    getAssignmentRepository,
-    getClassRepository,
-    getGroupRepository,
-    getQuestionRepository,
-    getStudentRepository,
-    getSubmissionRepository,
-} from '../data/repositories.js';
+import { EntityDTO } from '@mikro-orm/core';
+import { getGroupRepository, getStudentRepository, getSubmissionRepository } from '../data/repositories.js';
 import { Group } from '../entities/assignments/group.entity.js';
 import { mapToGroupDTO, mapToGroupDTOId } from '../interfaces/group.js';
 import { mapToSubmissionDTO, mapToSubmissionDTOId } from '../interfaces/submission.js';
 import { GroupDTO } from '@dwengo-1/common/interfaces/group';
 import { SubmissionDTO, SubmissionDTOId } from '@dwengo-1/common/interfaces/submission';
-import { getLogger } from '../logging/initalize.js';
 import { fetchAssignment } from './assignments.js';
 import { NotFoundException } from '../exceptions/not-found-exception.js';
-import { fetchClass } from './classes.js';
 import { putObject } from './service-helper.js';
 
 export async function fetchGroup(classId: string, assignmentNumber: number, groupNumber: number): Promise<Group> {
@@ -40,7 +31,7 @@ export async function putGroup(
     classId: string,
     assignmentNumber: number,
     groupNumber: number,
-    groupData: Partial<EntityDTO<Group>>
+    groupData: Partial<EntityDTO<Group>>,
 ): Promise<GroupDTO> {
     const group = await fetchGroup(classId, assignmentNumber, groupNumber);
 
@@ -59,7 +50,7 @@ export async function deleteGroup(classId: string, assignmentNumber: number, gro
     return mapToGroupDTO(group);
 }
 
-export async function getExistingGroupFromGroupDTO(groupData: GroupDTO) {
+export async function getExistingGroupFromGroupDTO(groupData: GroupDTO): Promise<Group> {
     const classId = typeof groupData.class === 'string' ? groupData.class : groupData.class.id;
     const assignmentNumber = typeof groupData.assignment === 'number' ? groupData.assignment : groupData.assignment.id;
     const groupNumber = groupData.groupNumber;
@@ -72,7 +63,7 @@ export async function createGroup(groupData: GroupDTO, classid: string, assignme
 
     const memberUsernames = (groupData.members as string[]) || [];
     const members = (await Promise.all([...memberUsernames].map(async (id) => studentRepository.findByUsername(id)))).filter(
-        (student) => student !== null
+        (student) => student !== null,
     );
 
     const assignment = await fetchAssignment(classid, assignmentNumber);
@@ -104,7 +95,7 @@ export async function getGroupSubmissions(
     classId: string,
     assignmentNumber: number,
     groupNumber: number,
-    full: boolean
+    full: boolean,
 ): Promise<SubmissionDTO[] | SubmissionDTOId[]> {
     const group = await fetchGroup(classId, assignmentNumber, groupNumber);
 
diff --git a/backend/src/services/submissions.ts b/backend/src/services/submissions.ts
index 25f6e7f0..c7daff74 100644
--- a/backend/src/services/submissions.ts
+++ b/backend/src/services/submissions.ts
@@ -3,9 +3,8 @@ import { LearningObjectIdentifier } from '../entities/content/learning-object-id
 import { NotFoundException } from '../exceptions/not-found-exception.js';
 import { mapToSubmission, mapToSubmissionDTO } from '../interfaces/submission.js';
 import { SubmissionDTO } from '@dwengo-1/common/interfaces/submission';
-import { Language } from '@dwengo-1/common/util/language';
 import { fetchStudent } from './students.js';
-import { fetchGroup, getExistingGroupFromGroupDTO } from './groups.js';
+import { getExistingGroupFromGroupDTO } from './groups.js';
 import { Submission } from '../entities/assignments/submission.entity.js';
 
 export async function fetchSubmission(loId: LearningObjectIdentifier, submissionNumber: number): Promise<Submission> {