diff --git a/apps/server/package.json b/apps/server/package.json
index cffdebe1e..ced038929 100644
--- a/apps/server/package.json
+++ b/apps/server/package.json
@@ -27,7 +27,9 @@
     "ws": "^8.13.0"
   },
   "devDependencies": {
+    "@types/cors": "^2.8.17",
     "@types/express": "^4.17.17",
+    "@types/multer": "^1.4.11",
     "@types/node": "^18.11.18",
     "@types/node-osc": "^6.0.2",
     "@types/websocket": "^1.0.5",
diff --git a/apps/server/src/adapters/WebsocketAdapter.ts b/apps/server/src/adapters/WebsocketAdapter.ts
index f0cea0cae..1bf7a9289 100644
--- a/apps/server/src/adapters/WebsocketAdapter.ts
+++ b/apps/server/src/adapters/WebsocketAdapter.ts
@@ -25,7 +25,7 @@ import { eventStore } from '../stores/EventStore.js';
 import { dispatchFromAdapter } from '../controllers/integrationController.js';
 import { logger } from '../classes/Logger.js';
 
-let instance;
+let instance: SocketServer | null = null;
 
 export class SocketServer implements IAdapter {
   private readonly MAX_PAYLOAD = 1024 * 256; // 256Kb
@@ -50,7 +50,7 @@ export class SocketServer implements IAdapter {
     this.wss.on('connection', (ws) => {
       let clientId = getRandomName();
       this.clientIds.add(clientId);
-      logger.info(LogOrigin.Client, `${this.wss.clients.size} Connections with new: ${clientId}`);
+      logger.info(LogOrigin.Client, `${this.clientIds.size} Connections with new: ${clientId}`);
 
       // send store payload on connect
       ws.send(
@@ -70,8 +70,8 @@ export class SocketServer implements IAdapter {
       ws.on('error', console.error);
 
       ws.on('close', () => {
-        logger.info(LogOrigin.Client, `${this.wss.clients.size} Connections with disconnected: ${clientId}`);
         this.clientIds.delete(clientId);
+        logger.info(LogOrigin.Client, `${this.clientIds.size} Connections with disconnected: ${clientId}`);
       });
 
       ws.on('message', (data) => {
diff --git a/apps/server/src/adapters/utils/__test__/parse.test.ts b/apps/server/src/adapters/utils/__test__/parse.test.ts
index 48990c595..aba4eb060 100644
--- a/apps/server/src/adapters/utils/__test__/parse.test.ts
+++ b/apps/server/src/adapters/utils/__test__/parse.test.ts
@@ -33,8 +33,8 @@ describe('objectFromPath()', () => {
     const obj = objectFromPath(arr);
     expect(obj).toStrictEqual(objExpected);
   });
-  it('empty array creates undefinde object', () => {
-    const arr = [];
+  it('empty array creates undefined object', () => {
+    const arr: string[] = [];
     const value = '1234567890';
     const objExpected = null;
 
diff --git a/apps/server/src/app.ts b/apps/server/src/app.ts
index 322ac2071..c351f3900 100644
--- a/apps/server/src/app.ts
+++ b/apps/server/src/app.ts
@@ -170,8 +170,8 @@ export const startServer = async () => {
     eventNext: state.eventNext,
     publicEventNext: state.publicEventNext,
     timer1: {
-      duration: null,
-      current: null,
+      duration: 0,
+      current: 0,
       playback: SimplePlayback.Stop,
       direction: SimpleDirection.CountDown,
     },
diff --git a/apps/server/src/classes/data-provider/DataProvider.ts b/apps/server/src/classes/data-provider/DataProvider.ts
index a3074cb85..b15073a0c 100644
--- a/apps/server/src/classes/data-provider/DataProvider.ts
+++ b/apps/server/src/classes/data-provider/DataProvider.ts
@@ -11,6 +11,7 @@ import {
   UserFields,
   Alias,
   Settings,
+  HttpSettings,
 } from 'ontime-types';
 
 import { data, db } from '../../modules/loadDb.js';
@@ -98,7 +99,7 @@ export class DataProvider {
     await this.persist();
   }
 
-  static async setHttp(newData) {
+  static async setHttp(newData: HttpSettings) {
     data.http = { ...newData };
     await this.persist();
   }
diff --git a/apps/server/src/classes/simple-timer/SimpleTimer.ts b/apps/server/src/classes/simple-timer/SimpleTimer.ts
index baea1e712..31e31ca97 100644
--- a/apps/server/src/classes/simple-timer/SimpleTimer.ts
+++ b/apps/server/src/classes/simple-timer/SimpleTimer.ts
@@ -38,7 +38,8 @@ export class SimpleTimer {
 
   public start(timeNow: number): SimpleTimerState {
     if (this.state.playback === SimplePlayback.Pause) {
-      const elapsedSincePause = this.pausedAt - this.startedAt;
+      // eslint-disable-next-line @typescript-eslint/no-non-null-assertion -- we know these are not null in a timer that is paused
+      const elapsedSincePause = this.pausedAt! - this.startedAt!;
       this.startedAt = timeNow - elapsedSincePause;
     } else if (this.state.playback === SimplePlayback.Stop) {
       this.startedAt = timeNow;
diff --git a/apps/server/src/controllers/ontimeController.ts b/apps/server/src/controllers/ontimeController.ts
index 1275d31f9..9e30b1c44 100644
--- a/apps/server/src/controllers/ontimeController.ts
+++ b/apps/server/src/controllers/ontimeController.ts
@@ -8,7 +8,7 @@ import type {
   ErrorResponse,
   ProjectFileListResponse,
 } from 'ontime-types';
-import { deepmerge } from 'ontime-utils';
+import { ExcelImportOptions, deepmerge } from 'ontime-utils';
 
 import { RequestHandler, Request, Response } from 'express';
 import fs from 'fs';
@@ -44,7 +44,7 @@ import { removeFileExtension } from '../utils/removeFileExtension.js';
 
 // Create controller for GET request to '/ontime/poll'
 // Returns data for current state
-export const poll = async (_req, res) => {
+export const poll = async (_req: Request, res: Response) => {
   try {
     const state = eventStore.poll();
     res.status(200).send(state);
@@ -57,7 +57,7 @@ export const poll = async (_req, res) => {
 
 // Create controller for GET request to '/ontime/db'
 // Returns -
-export const dbDownload = async (req, res) => {
+export const dbDownload = async (_req: Request, res: Response) => {
   const { title } = DataProvider.getProjectData();
   const fileTitle = title || 'ontime data';
 
@@ -77,7 +77,7 @@ export const dbDownload = async (req, res) => {
  * @param _res
  * @param options
  */
-async function parseFile(file, _req, _res, options) {
+async function parseFile(file, _req: Request, _res: Response, options: ExcelImportOptions) {
   if (!fs.existsSync(file)) {
     throw new Error('Upload failed');
   }
@@ -85,6 +85,10 @@ async function parseFile(file, _req, _res, options) {
   return result.data;
 }
 
+export type ParsingOptions = {
+  onlyRundown?: 'true' | 'false';
+};
+
 /**
  * parse an uploaded file and apply its parsed objects
  * @param file
@@ -93,7 +97,7 @@ async function parseFile(file, _req, _res, options) {
  * @param [options]
  * @returns {Promise<void>}
  */
-const parseAndApply = async (file, _req, res, options) => {
+const parseAndApply = async (file, _req: Request, res: Response, options) => {
   const result = await parseFile(file, _req, res, options);
 
   runtimeService.stop();
@@ -134,7 +138,7 @@ const getNetworkInterfaces = () => {
 
 // Create controller for GET request to '/ontime/info'
 // Returns -
-export const getInfo = async (req: Request, res: Response<GetInfo>) => {
+export const getInfo = async (_req: Request, res: Response<GetInfo>) => {
   const { version, serverPort } = DataProvider.getSettings();
   const osc = DataProvider.getOsc();
 
@@ -155,14 +159,14 @@ export const getInfo = async (req: Request, res: Response<GetInfo>) => {
 
 // Create controller for POST request to '/ontime/aliases'
 // Returns -
-export const getAliases = async (req, res) => {
+export const getAliases = async (_req: Request, res: Response) => {
   const aliases = DataProvider.getAliases();
   res.status(200).send(aliases);
 };
 
 // Create controller for POST request to '/ontime/aliases'
 // Returns ACK message
-export const postAliases = async (req, res) => {
+export const postAliases = async (req: Request, res: Response) => {
   if (failIsNotArray(req.body, res)) {
     return;
   }
@@ -178,20 +182,20 @@ export const postAliases = async (req, res) => {
     await DataProvider.setAliases(newAliases);
     res.status(200).send(newAliases);
   } catch (error) {
-    res.status(400).send({ message: error.toString() });
+    res.status(400).send({ message: String(error) });
   }
 };
 
 // Create controller for GET request to '/ontime/userfields'
 // Returns -
-export const getUserFields = async (req, res) => {
+export const getUserFields = async (_req: Request, res: Response) => {
   const userFields = DataProvider.getUserFields();
   res.status(200).send(userFields);
 };
 
 // Create controller for POST request to '/ontime/userfields'
 // Returns ACK message
-export const postUserFields = async (req, res) => {
+export const postUserFields = async (req: Request, res: Response) => {
   if (failEmptyObjects(req.body, res)) {
     return;
   }
@@ -201,13 +205,13 @@ export const postUserFields = async (req, res) => {
     await DataProvider.setUserFields(newData);
     res.status(200).send(newData);
   } catch (error) {
-    res.status(400).send({ message: error.toString() });
+    res.status(400).send({ message: String(error) });
   }
 };
 
 // Create controller for POST request to '/ontime/settings'
 // Returns -
-export const getSettings = async (req, res) => {
+export const getSettings = async (_req: Request, res: Response) => {
   const settings = DataProvider.getSettings();
   res.status(200).send(settings);
 };
@@ -227,7 +231,7 @@ function extractPin(value: string | undefined | null, fallback: string | null):
 
 // Create controller for POST request to '/ontime/settings'
 // Returns ACK message
-export const postSettings = async (req, res) => {
+export const postSettings = async (req: Request, res: Response) => {
   if (failEmptyObjects(req.body, res)) {
     return;
   }
@@ -264,7 +268,7 @@ export const postSettings = async (req, res) => {
     await DataProvider.setSettings(newData);
     res.status(200).send(newData);
   } catch (error) {
-    res.status(400).send({ message: error.toString() });
+    res.status(400).send({ message: String(error) });
   }
 };
 
@@ -272,7 +276,7 @@ export const postSettings = async (req, res) => {
  * @description Get view Settings
  * @method GET
  */
-export const getViewSettings = async (req, res) => {
+export const getViewSettings = async (_req: Request, res: Response) => {
   const views = DataProvider.getViewSettings();
   res.status(200).send(views);
 };
@@ -281,7 +285,7 @@ export const getViewSettings = async (req, res) => {
  * @description Change view Settings
  * @method POST
  */
-export const postViewSettings = async (req, res) => {
+export const postViewSettings = async (req: Request, res: Response) => {
   if (failEmptyObjects(req.body, res)) {
     return;
   }
@@ -299,20 +303,20 @@ export const postViewSettings = async (req, res) => {
     await DataProvider.setViewSettings(newData);
     res.status(200).send(newData);
   } catch (error) {
-    res.status(400).send({ message: error.toString() });
+    res.status(400).send({ message: String(error) });
   }
 };
 
 // Create controller for GET request to '/ontime/osc'
 // Returns -
-export const getOSC = async (req, res) => {
+export const getOSC = async (_req: Request, res: Response) => {
   const osc = DataProvider.getOsc();
   res.status(200).send(osc);
 };
 
 // Create controller for POST request to '/ontime/osc'
 // Returns ACK message
-export const postOSC = async (req, res) => {
+export const postOSC = async (req: Request, res: Response) => {
   if (failEmptyObjects(req.body, res)) {
     return;
   }
@@ -333,11 +337,11 @@ export const postOSC = async (req, res) => {
 
     res.send(oscSettings).status(200);
   } catch (error) {
-    res.status(400).send({ message: error.toString() });
+    res.status(400).send({ message: String(error) });
   }
 };
 
-export const postOscSubscriptions = async (req, res) => {
+export const postOscSubscriptions = async (req: Request, res: Response) => {
   if (failEmptyObjects(req.body, res)) {
     return;
   }
@@ -354,18 +358,18 @@ export const postOscSubscriptions = async (req, res) => {
 
     res.send(oscSettings).status(200);
   } catch (error) {
-    res.status(400).send({ message: error.toString() });
+    res.status(400).send({ message: String(error) });
   }
 };
 
 // Create controller for GET request to '/ontime/http'
-export const getHTTP = async (_req, res: Response<HttpSettings>) => {
+export const getHTTP = async (_req: Request, res: Response<HttpSettings>) => {
   const http = DataProvider.getHttp();
   res.status(200).send(http);
 };
 
 // Create controller for POST request to '/ontime/http'
-export const postHTTP = async (req, res) => {
+export const postHTTP = async (req: Request, res: Response) => {
   if (failEmptyObjects(req.body, res)) {
     return;
   }
@@ -386,11 +390,11 @@ export const postHTTP = async (req, res) => {
 
     res.send(httpSettings).status(200);
   } catch (error) {
-    res.status(400).send({ message: error.toString() });
+    res.status(400).send({ message: String(error) });
   }
 };
 
-export async function patchPartialProjectFile(req, res) {
+export async function patchPartialProjectFile(req: Request, res: Response) {
   if (failEmptyObjects(req.body, res)) {
     return;
   }
@@ -414,14 +418,14 @@ export async function patchPartialProjectFile(req, res) {
     }
     res.status(200).send();
   } catch (error) {
-    res.status(400).send({ message: error.toString() });
+    res.status(400).send({ message: String(error) });
   }
 }
 
 /**
  * uploads, parses and applies the data from a given file
  */
-export const dbUpload = async (req, res) => {
+export const dbUpload = async (req: Request, res: Response) => {
   if (!req.file) {
     res.status(400).send({ message: 'File not found' });
     return;
@@ -440,7 +444,7 @@ export const dbUpload = async (req, res) => {
  * uploads and parses an excel file
  * @returns parsed result
  */
-export async function previewExcel(req, res) {
+export async function previewExcel(req, res: Response) {
   if (!req.file) {
     res.status(400).send({ message: 'File not found' });
     return;
@@ -452,7 +456,7 @@ export async function previewExcel(req, res) {
     const data = await parseFile(file, req, res, options);
     res.status(200).send(data);
   } catch (error) {
-    res.status(500).send({ message: error.toString() });
+    res.status(500).send({ message: String(error) });
   }
 }
 
@@ -475,7 +479,7 @@ export const postNew: RequestHandler = async (req, res) => {
     await deleteAllEvents();
     res.status(201).send(newData);
   } catch (error) {
-    res.status(400).send({ message: error.toString() });
+    res.status(400).send({ message: String(error) });
   }
 };
 
@@ -497,7 +501,7 @@ export const listProjects: RequestHandler = async (_, res: Response<ProjectFileL
       lastLoadedProject: lastLoadedProjectName,
     });
   } catch (error) {
-    res.status(500).send({ message: error.toString() });
+    res.status(500).send({ message: String(error) });
   }
 };
 
@@ -523,7 +527,7 @@ export const loadProject: RequestHandler = async (req, res) => {
       message: `Loaded project ${filename}`,
     });
   } catch (error) {
-    res.status(500).send({ message: error.toString() });
+    res.status(500).send({ message: String(error) });
   }
 };
 
@@ -537,7 +541,7 @@ export const loadProject: RequestHandler = async (req, res) => {
  *                         a 409 status if there are validation errors,
  *                         or a 500 status with an error message in case of an exception.
  */
-export const duplicateProjectFile: RequestHandler = async (req, res) => {
+export const duplicateProjectFile: RequestHandler = async (req: Request, res: Response) => {
   try {
     const { filename } = req.params;
     const { newFilename } = req.body;
@@ -557,7 +561,7 @@ export const duplicateProjectFile: RequestHandler = async (req, res) => {
       message: `Duplicated project ${filename} to ${newFilename}`,
     });
   } catch (error) {
-    res.status(500).send({ message: error.toString() });
+    res.status(500).send({ message: String(error) });
   }
 };
 
@@ -571,7 +575,7 @@ export const duplicateProjectFile: RequestHandler = async (req, res) => {
  *                         a 409 status if there are validation errors,
  *                         or a 500 status with an error message in case of an exception.
  */
-export const renameProjectFile: RequestHandler = async (req, res) => {
+export const renameProjectFile: RequestHandler = async (req: Request, res: Response) => {
   try {
     const { newFilename } = req.body;
     const { filename } = req.params;
@@ -599,7 +603,7 @@ export const renameProjectFile: RequestHandler = async (req, res) => {
       message: `Renamed project ${filename} to ${newFilename}`,
     });
   } catch (error) {
-    res.status(500).send({ message: error.toString() });
+    res.status(500).send({ message: String(error) });
   }
 };
 
@@ -612,7 +616,7 @@ export const renameProjectFile: RequestHandler = async (req, res) => {
  *                         a 409 status if there are validation errors,
  *                         or a 500 status with an error message in case of an exception.
  */
-export const createProjectFile: RequestHandler = async (req, res) => {
+export const createProjectFile: RequestHandler = async (req: Request, res: Response) => {
   try {
     const { filename } = req.body;
 
@@ -624,14 +628,13 @@ export const createProjectFile: RequestHandler = async (req, res) => {
       return res.status(409).send({ message: errors.join(', ') });
     }
 
-    console.log(`----------------> Creating directory createProjectFile:  ${projectFilePath}`);
     await writeFile(projectFilePath, JSON.stringify(dbModel));
 
     res.status(200).send({
       message: `Created project ${filename}`,
     });
   } catch (error) {
-    res.status(500).send({ message: error.toString() });
+    res.status(500).send({ message: String(error) });
   }
 };
 
@@ -645,7 +648,7 @@ export const createProjectFile: RequestHandler = async (req, res) => {
  *                         a 409 status if there are validation errors,
  *                         or a 500 status with an error message in case of an exception.
  */
-export const deleteProjectFile: RequestHandler = async (req, res) => {
+export const deleteProjectFile: RequestHandler = async (req: Request, res: Response) => {
   try {
     const { filename } = req.params;
 
@@ -669,7 +672,7 @@ export const deleteProjectFile: RequestHandler = async (req, res) => {
       message: `Deleted project ${filename}`,
     });
   } catch (error) {
-    res.status(500).send({ message: error.toString() });
+    res.status(500).send({ message: String(error) });
   }
 };
 
@@ -678,7 +681,7 @@ export const deleteProjectFile: RequestHandler = async (req, res) => {
  * @description SETP-1 POST Client Secrect
  * @returns parsed result
  */
-export async function uploadSheetClientFile(req, res) {
+export async function uploadSheetClientFile(req, res: Response) {
   if (!req.file.path) {
     res.status(400).send({ message: 'File not found' });
     return;
@@ -688,7 +691,7 @@ export async function uploadSheetClientFile(req, res) {
     await sheet.saveClientSecrets(client);
     res.status(200).send('OK');
   } catch (error) {
-    res.status(500).send({ message: error.toString() });
+    res.status(500).send({ message: String(error) });
   }
   fs.unlink(req.file.path, (err) => {
     if (err) logger.error(LogOrigin.Server, err.message);
@@ -698,7 +701,7 @@ export async function uploadSheetClientFile(req, res) {
 /**
  * @description STEP-1 GET Client Secrect status
  */
-export const getClientSecrect = async (req, res) => {
+export const getClientSecrect = async (req: Request, res: Response) => {
   try {
     const clientSecrectExists = await sheet.testClientSecret();
     if (clientSecrectExists) {
@@ -707,31 +710,31 @@ export const getClientSecrect = async (req, res) => {
       res.status(500).send({ message: 'The Client ID does not exist' });
     }
   } catch (error) {
-    res.status(500).send({ message: error.toString() });
+    res.status(500).send({ message: String(error) });
   }
 };
 
 /**
  * @description STEP-2 GET sheet authentication url
  */
-export async function getAuthenticationUrl(req, res) {
+export async function getAuthenticationUrl(_req: Request, res: Response) {
   try {
     const authUrl = await sheet.openAuthServer();
     res.status(200).send(authUrl);
   } catch (error) {
-    res.status(500).send({ message: error.toString() });
+    res.status(500).send({ message: String(error) });
   }
 }
 
 /**
  * @description STEP-2 GET sheet authentication status
  */
-export const getAuthentication = async (req, res) => {
+export const getAuthentication = async (_req: Request, res: Response) => {
   try {
     await sheet.testAuthentication();
     res.status(200).send();
   } catch (error) {
-    res.status(500).send({ message: error.toString() });
+    res.status(500).send({ message: String(error) });
   }
 };
 
@@ -739,7 +742,7 @@ export const getAuthentication = async (req, res) => {
  * @description STEP-3 POST sheet id
  * @returns list of worksheets
  */
-export const postId = async (req, res) => {
+export const postId = async (req: Request, res: Response) => {
   try {
     const { id } = req.body;
     if (id.lenght < 40) {
@@ -748,20 +751,20 @@ export const postId = async (req, res) => {
     const state = await sheet.testSheetId(id);
     res.status(200).send(state);
   } catch (error) {
-    res.status(500).send({ message: error.toString() });
+    res.status(500).send({ message: String(error) });
   }
 };
 
 /**
  * @description STEP-4 POST worksheet
  */
-export const postWorksheet = async (req, res) => {
+export const postWorksheet = async (req: Request, res: Response) => {
   try {
     const { worksheet, id } = req.body;
     const state = await sheet.testWorksheet(worksheet, id);
     res.status(200).send(state);
   } catch (error) {
-    res.status(500).send({ message: error.toString() });
+    res.status(500).send({ message: String(error) });
   }
 };
 
@@ -769,25 +772,25 @@ export const postWorksheet = async (req, res) => {
  * @description STEP-5 POST download undown to sheet
  * @returns parsed result
  */
-export async function pullSheet(req, res) {
+export async function pullSheet(req: Request, res: Response) {
   try {
     const { id, options } = req.body;
     const data = await sheet.pull(id, options);
     res.status(200).send(data);
   } catch (error) {
-    res.status(500).send({ message: error.toString() });
+    res.status(500).send({ message: String(error) });
   }
 }
 
 /**
  * @description STEP-5 POST upload rundown to sheet
  */
-export async function pushSheet(req, res) {
+export async function pushSheet(req: Request, res: Response) {
   try {
     const { id, options } = req.body;
     await sheet.push(id, options);
     res.status(200).send();
   } catch (error) {
-    res.status(500).send({ message: error.toString() });
+    res.status(500).send({ message: String(error) });
   }
 }
diff --git a/apps/server/src/controllers/ontimeController.validate.ts b/apps/server/src/controllers/ontimeController.validate.ts
index 7e34d0136..862392935 100644
--- a/apps/server/src/controllers/ontimeController.validate.ts
+++ b/apps/server/src/controllers/ontimeController.validate.ts
@@ -255,7 +255,7 @@ export const validateProjectCreate = [
  *
  */
 export const validateProjectFiles = (projectFiles: { filename?: string; newFilename?: string }): Array<string> => {
-  const errors = [];
+  const errors: string[] = [];
 
   if (projectFiles.filename) {
     const projectFilePath = join(uploadsFolderPath, projectFiles.filename);
diff --git a/apps/server/src/modules/loadDb.ts b/apps/server/src/modules/loadDb.ts
index b0d1da656..7a324588f 100644
--- a/apps/server/src/modules/loadDb.ts
+++ b/apps/server/src/modules/loadDb.ts
@@ -35,7 +35,7 @@ const populateDb = () => {
  * @param adapterToUse
  * @return {Promise<number|*>}
  */
-const parseDb = async (fileToRead, adapterToUse) => {
+const parseDb = async (fileToRead: string, adapterToUse: Low<DatabaseModel>) => {
   if (validateFile(fileToRead)) {
     await adapterToUse.read();
   } else {
diff --git a/apps/server/src/services/TimerService.ts b/apps/server/src/services/TimerService.ts
index ea9104f42..7b344e316 100644
--- a/apps/server/src/services/TimerService.ts
+++ b/apps/server/src/services/TimerService.ts
@@ -81,7 +81,7 @@ export class TimerService {
       const newState = runtimeState.getState();
 
       // handle end action if there was a timer playing
-      if (newState.timer.playback === Playback.Play) {
+      if (newState.timer.playback === Playback.Play && newState.eventNow) {
         if (newState.eventNow.endAction === EndAction.Stop) {
           runtimeState.stop();
         } else if (newState.eventNow.endAction === EndAction.LoadNext) {
diff --git a/apps/server/src/services/__tests__/timerUtils.test.ts b/apps/server/src/services/__tests__/timerUtils.test.ts
index ce363d602..ca159a9f5 100644
--- a/apps/server/src/services/__tests__/timerUtils.test.ts
+++ b/apps/server/src/services/__tests__/timerUtils.test.ts
@@ -860,7 +860,7 @@ describe('getRollTimers()', () => {
       publicIndex: null,
       nextIndex: 0,
       publicNextIndex: 4,
-      timeToNext: dayInMs - now + eventlist[0].timeStart,
+      timeToNext: dayInMs - now + eventlist[0].timeStart!,
       nextEvent: eventlist[0],
       nextPublicEvent: eventlist[4],
       currentEvent: null,
@@ -887,7 +887,7 @@ describe('getRollTimers()', () => {
       publicIndex: null,
       nextIndex: 0,
       publicNextIndex: 0,
-      timeToNext: dayInMs - now + singleEventList[0].timeStart,
+      timeToNext: dayInMs - now + singleEventList[0].timeStart!,
       nextEvent: singleEventList[0],
       nextPublicEvent: singleEventList[0],
       currentEvent: null,
diff --git a/apps/server/src/services/integration-service/integrationUtils.ts b/apps/server/src/services/integration-service/integrationUtils.ts
index b69d5a207..191884c73 100644
--- a/apps/server/src/services/integration-service/integrationUtils.ts
+++ b/apps/server/src/services/integration-service/integrationUtils.ts
@@ -1,10 +1,11 @@
+import { MaybeNumber } from 'ontime-types';
 import { millisToString, removeLeadingZero } from 'ontime-utils';
 
 // any value inside double curly braces {{val}}
 const placeholderRegex = /{{(.*?)}}/g;
 
 function formatDisplayFromString(value: string, hideZero = false): string {
-  let valueInNumber = null;
+  let valueInNumber: MaybeNumber = null;
 
   if (value !== 'null') {
     const parsedValue = Number(value);
@@ -48,7 +49,7 @@ export function parseTemplateNested(template: string, state: object, humanReadab
   for (const match of matches) {
     const variableName = match[1];
     const variableParts = variableName.split('.');
-    let value = undefined;
+    let value: string | undefined = undefined;
 
     if (variableParts[0] === 'human') {
       const lookupKey = variableParts[1];
diff --git a/apps/server/src/services/message-service/MessageService.ts b/apps/server/src/services/message-service/MessageService.ts
index f114058e6..9a2750545 100644
--- a/apps/server/src/services/message-service/MessageService.ts
+++ b/apps/server/src/services/message-service/MessageService.ts
@@ -4,7 +4,7 @@ import { throttle } from '../../utils/throttle.js';
 
 import type { PublishFn } from '../../stores/EventStore.js';
 
-let instance;
+let instance: MessageService | null = null;
 
 class MessageService {
   timer: TimerMessage;
@@ -56,7 +56,7 @@ class MessageService {
 
   init(publish: PublishFn) {
     this.publish = publish;
-    this.throttledSet = throttle((key, value) => this.publish(key, value), 100);
+    this.throttledSet = throttle((key, value) => this.publish?.(key, value), 100);
   }
 
   getState(): MessageState {
diff --git a/apps/server/src/services/rundown-service/RundownService.ts b/apps/server/src/services/rundown-service/RundownService.ts
index da6299f86..e0fb9bcd5 100644
--- a/apps/server/src/services/rundown-service/RundownService.ts
+++ b/apps/server/src/services/rundown-service/RundownService.ts
@@ -104,7 +104,8 @@ export async function editEvent(patch: Partial<OntimeEvent> | Partial<OntimeBloc
   }
 
   const scopedMutation = cache.mutateCache(cache.edit);
-  const { newEvent } = await scopedMutation({ patch, eventId: patch.id });
+  // eslint-disable-next-line @typescript-eslint/no-non-null-assertion -- we know patch has an id
+  const { newEvent } = await scopedMutation({ patch, eventId: patch.id! });
 
   notifyChanges({ timer: [patch.id], external: true });
 
diff --git a/apps/server/src/services/rundown-service/rundownCache.ts b/apps/server/src/services/rundown-service/rundownCache.ts
index dcdd41d81..0a848adf6 100644
--- a/apps/server/src/services/rundown-service/rundownCache.ts
+++ b/apps/server/src/services/rundown-service/rundownCache.ts
@@ -104,7 +104,7 @@ export function get(): Readonly<RundownCache> {
 }
 
 type CommonParams = { persistedRundown: OntimeRundown };
-type MutationParams<T> = T & Partial<CommonParams>;
+type MutationParams<T> = T & CommonParams;
 type MutatingReturn = {
   newRundown: OntimeRundown;
   newEvent?: OntimeRundownEntry;
diff --git a/apps/server/src/services/runtime-service/RuntimeService.ts b/apps/server/src/services/runtime-service/RuntimeService.ts
index 644840a8f..9eb2681a5 100644
--- a/apps/server/src/services/runtime-service/RuntimeService.ts
+++ b/apps/server/src/services/runtime-service/RuntimeService.ts
@@ -166,6 +166,9 @@ class RuntimeService {
    */
   startById(eventId: string): boolean {
     const event = getEventWithId(eventId);
+    if (!event) {
+      return false;
+    }
     const success = this.loadEvent(event);
     if (success) {
       this.start();
@@ -180,6 +183,9 @@ class RuntimeService {
    */
   startByIndex(eventIndex: number): boolean {
     const event = getEventAtIndex(eventIndex);
+    if (!event) {
+      return false;
+    }
     const success = this.loadEvent(event);
     if (success) {
       this.start();
@@ -194,6 +200,9 @@ class RuntimeService {
    */
   startByCue(cue: string): boolean {
     const event = getEventWithCue(cue);
+    if (!event) {
+      return false;
+    }
     const success = this.loadEvent(event);
     if (success) {
       this.start();
@@ -208,6 +217,9 @@ class RuntimeService {
    */
   loadById(eventId: string): boolean {
     const event = getEventWithId(eventId);
+    if (!event) {
+      return false;
+    }
     const success = this.loadEvent(event);
     return success;
   }
@@ -219,6 +231,9 @@ class RuntimeService {
    */
   loadByIndex(eventIndex: number): boolean {
     const event = getEventAtIndex(eventIndex);
+    if (!event) {
+      return false;
+    }
     const success = this.loadEvent(event);
     return success;
   }
@@ -230,6 +245,9 @@ class RuntimeService {
    */
   loadByCue(cue: string): boolean {
     const event = getEventWithCue(cue);
+    if (!event) {
+      return false;
+    }
     const success = this.loadEvent(event);
     return success;
   }
diff --git a/apps/server/src/services/timerUtils.ts b/apps/server/src/services/timerUtils.ts
index f0886f085..a08bfe9c6 100644
--- a/apps/server/src/services/timerUtils.ts
+++ b/apps/server/src/services/timerUtils.ts
@@ -14,6 +14,11 @@ export const normaliseEndTime = (start: number, end: number) => (end < start ? e
  */
 export function getExpectedFinish(state: RuntimeState): MaybeNumber {
   const { startedAt, finishedAt, duration, addedTime } = state.timer;
+
+  if (state.eventNow === null) {
+    return null;
+  }
+
   const { timerType, timeEnd } = state.eventNow;
   const { pausedAt } = state._timer;
   const { clock } = state;
@@ -33,7 +38,8 @@ export function getExpectedFinish(state: RuntimeState): MaybeNumber {
   }
 
   // handle events that finish the day after
-  const expectedFinish = startedAt + duration + addedTime + pausedTime;
+  // eslint-disable-next-line @typescript-eslint/no-non-null-assertion -- duration exists if ther eis a timer
+  const expectedFinish = startedAt + duration! + addedTime + pausedTime;
   if (expectedFinish > dayInMs) {
     return expectedFinish - dayInMs;
   }
diff --git a/apps/server/src/setup.ts b/apps/server/src/setup.ts
index 404ecdfe5..7c8575def 100644
--- a/apps/server/src/setup.ts
+++ b/apps/server/src/setup.ts
@@ -19,13 +19,13 @@ export function getAppDataPath(): string {
 
   switch (process.platform) {
     case 'darwin': {
-      return path.join(process.env.HOME, 'Library', 'Application Support', 'Ontime');
+      return path.join(process.env.HOME!, 'Library', 'Application Support', 'Ontime');
     }
     case 'win32': {
-      return path.join(process.env.APPDATA, 'Ontime');
+      return path.join(process.env.APPDATA!, 'Ontime');
     }
     case 'linux': {
-      return path.join(process.env.HOME, '.Ontime');
+      return path.join(process.env.HOME!, '.Ontime');
     }
     default: {
       throw new Error('Could not resolve public folder for platform');
diff --git a/apps/server/src/stores/__tests__/runtimeState.test.ts b/apps/server/src/stores/__tests__/runtimeState.test.ts
index bedbc6003..384b314a3 100644
--- a/apps/server/src/stores/__tests__/runtimeState.test.ts
+++ b/apps/server/src/stores/__tests__/runtimeState.test.ts
@@ -77,7 +77,7 @@ describe('mutation on runtimeState', () => {
       // 1. Load event
       load(mockEvent, [mockEvent]);
       let newState = getState();
-      expect(newState.eventNow.id).toBe(mockEvent.id);
+      expect(newState.eventNow?.id).toBe(mockEvent.id);
       expect(newState.timer.playback).toBe(Playback.Armed);
       expect(newState.clock).not.toBe(666);
 
diff --git a/apps/server/src/utils/throttle.ts b/apps/server/src/utils/throttle.ts
index 275d9772b..c72853a6c 100644
--- a/apps/server/src/utils/throttle.ts
+++ b/apps/server/src/utils/throttle.ts
@@ -8,7 +8,7 @@
  */
 export function throttle<T extends any[], U>(cb: (...args: T) => U, delay: number) {
   let shouldWait = false;
-  let waitingArgs;
+  let waitingArgs: T | null = null;
   const timeoutFunc = () => {
     if (waitingArgs == null) {
       shouldWait = false;
diff --git a/apps/server/src/utils/upload.ts b/apps/server/src/utils/upload.ts
index 58144f72c..16950e791 100644
--- a/apps/server/src/utils/upload.ts
+++ b/apps/server/src/utils/upload.ts
@@ -1,4 +1,5 @@
-import multer from 'multer';
+import { Request } from 'express';
+import multer, { FileFilterCallback } from 'multer';
 import path from 'path';
 import fs from 'fs';
 
@@ -6,12 +7,12 @@ import { EXCEL_MIME, JSON_MIME } from './parser.js';
 import { ensureDirectory } from './fileManagement.js';
 import { getAppDataPath } from '../setup.js';
 
-function generateNewFileName(filePath, callback) {
+function generateNewFileName(filePath: string, callback: (newName: string) => void) {
   const baseName = path.basename(filePath, path.extname(filePath));
   const extension = path.extname(filePath);
   let counter = 1;
 
-  const checkExistence = (newPath) => {
+  const checkExistence = (newPath: string) => {
     fs.access(newPath, fs.constants.F_OK, (err) => {
       if (err) {
         // File with the new name does not exist, use this name
@@ -64,7 +65,7 @@ const storage = multer.diskStorage({
  * @argument file - reference to file
  * @return {boolean} - file allowed
  */
-const filterAllowed = (req, file, cb) => {
+const filterAllowed = (_req: Request, file: Express.Multer.File, cb: FileFilterCallback) => {
   if (file.mimetype.includes(JSON_MIME) || file.mimetype.includes(EXCEL_MIME)) {
     cb(null, true);
   } else {
diff --git a/apps/server/tsconfig.json b/apps/server/tsconfig.json
index f768b1a07..0e9b4333b 100644
--- a/apps/server/tsconfig.json
+++ b/apps/server/tsconfig.json
@@ -12,7 +12,7 @@
     "experimentalDecorators": true,
   },
   "include": [
-    "src/**/*"
+    "src/**/*.ts",
+    "src/**/*.js",
   ],
-  "exclude": ["node_modules", "build"],
 }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 624c0f387..f6b44cc41 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -304,9 +304,15 @@ importers:
         specifier: ^8.13.0
         version: 8.13.0
     devDependencies:
+      '@types/cors':
+        specifier: ^2.8.17
+        version: 2.8.17
       '@types/express':
         specifier: ^4.17.17
         version: 4.17.17
+      '@types/multer':
+        specifier: ^1.4.11
+        version: 1.4.11
       '@types/node':
         specifier: ^18.11.18
         version: 18.11.18
@@ -3161,6 +3167,12 @@ packages:
       '@types/node': 18.19.3
     dev: true
 
+  /@types/cors@2.8.17:
+    resolution: {integrity: sha512-8CGDvrBj1zgo2qE+oS3pOCyYNqCPryMWY2bGfwA0dcfopWGgxs+78df0Rs3rc9THP4JkOhLsAa+15VdpAqkcUA==}
+    dependencies:
+      '@types/node': 18.19.3
+    dev: true
+
   /@types/debug@4.1.12:
     resolution: {integrity: sha512-vIChWdVG3LG1SMxEvI/AK+FWJthlrqlTu7fbrlywTkkaONwk/UAGaULXRlf8vkzFBLVm0zkMdCquhL5aOjhXPQ==}
     dependencies:
@@ -3252,6 +3264,12 @@ packages:
     resolution: {integrity: sha512-nG96G3Wp6acyAgJqGasjODb+acrI7KltPiRxzHPXnP3NgI28bpQDRv53olbqGXbfcgF5aiiHmO3xpwEpS5Ld9g==}
     dev: true
 
+  /@types/multer@1.4.11:
+    resolution: {integrity: sha512-svK240gr6LVWvv3YGyhLlA+6LRRWA4mnGIU7RcNmgjBYFl6665wcXrRfxGp5tEPVHUNm5FMcmq7too9bxCwX/w==}
+    dependencies:
+      '@types/express': 4.17.17
+    dev: true
+
   /@types/node-osc@6.0.2:
     resolution: {integrity: sha512-/TxCH+NlDoI3hFA6b2O91dpnPAqBDkLb2HEIv5hMVdKnCiWTdJJv2sVnQdX38sBgnals8TjCQEGii+OcMVf2fg==}
     dependencies: