diff --git a/server/__mocks__/logger.ts b/server/__mocks__/logger.ts
index 418620c..eba31a8 100644
--- a/server/__mocks__/logger.ts
+++ b/server/__mocks__/logger.ts
@@ -1,5 +1,5 @@
-import { LogLevel, TaggedLogger } from "../types";
-import { ActivatableLogger } from "../logger";
+import type { LogLevel, TaggedLogger } from "../types";
+import type { ActivatableLogger } from "../logger";
 
 export type MockLogMessages = unknown[][];
 type TaggedLogMessages = {
diff --git a/server/db/__mocks__/database.ts b/server/db/__mocks__/database.ts
index 769b188..b5a9bc6 100644
--- a/server/db/__mocks__/database.ts
+++ b/server/db/__mocks__/database.ts
@@ -80,4 +80,4 @@ export class MockDatabase implements TypedDatabase {
 
 export const db: MockDatabase = new MockDatabase();
 
-export { TypedDatabase, Statement };
+export { Statement };
diff --git a/server/db/database.ts b/server/db/database.ts
index 3a96105..3259c50 100644
--- a/server/db/database.ts
+++ b/server/db/database.ts
@@ -6,7 +6,7 @@ import { config } from "../config";
 import Logger from "../logger";
 import { Database, open, Statement } from "sqlite";
 import * as sqlite3 from "sqlite3";
-import { RunResult, SqlType, TypedDatabase } from "../types";
+import type { RunResult, SqlType, TypedDatabase } from "../types";
 
 const pglob = util.promisify(glob);
 const pReadFile = util.promisify(fs.readFile);
diff --git a/server/mail/index.ts b/server/mail/index.ts
index 3bf343b..5eb69fd 100644
--- a/server/mail/index.ts
+++ b/server/mail/index.ts
@@ -1,7 +1,7 @@
 import { createTransport, Transporter } from "nodemailer";
 import { config } from "../config";
 import * as MailTemplateService from "../services/mailTemplateService";
-import Mail from "nodemailer/lib/mailer";
+import type Mail from "nodemailer/lib/mailer";
 import SMTPTransport from "nodemailer/lib/smtp-transport";
 
 let transporterSingleton: Transporter | null = null;
diff --git a/server/resources/frontendResource.ts b/server/resources/frontendResource.ts
index 6fcd278..d1096af 100644
--- a/server/resources/frontendResource.ts
+++ b/server/resources/frontendResource.ts
@@ -3,7 +3,7 @@ import { promises as fs } from "graceful-fs";
 import ErrorTypes from "../utils/errorTypes";
 import Logger from "../logger";
 import * as Resources from "../utils/resources";
-import { Request, Response } from "express";
+import type { Request, Response } from "express";
 
 const indexHtml = __dirname + "/../../client/index.html";
 
diff --git a/server/resources/mailResource.ts b/server/resources/mailResource.ts
index 143a648..6c0cea1 100644
--- a/server/resources/mailResource.ts
+++ b/server/resources/mailResource.ts
@@ -5,7 +5,7 @@ import * as Resources from "../utils/resources";
 import { handleJSONWithData, RequestData } from "../utils/resources";
 import { normalizeString, parseInteger } from "../shared/utils/strings";
 import { forConstraint } from "../shared/validation/validator";
-import { Request, Response } from "express";
+import type { Request, Response } from "express";
 import { isString, Mail, MailId } from "../types";
 
 const isValidId = forConstraint(CONSTRAINTS.id, false);
diff --git a/server/resources/monitoringResource.ts b/server/resources/monitoringResource.ts
index e81ec55..a1be4bb 100644
--- a/server/resources/monitoringResource.ts
+++ b/server/resources/monitoringResource.ts
@@ -5,7 +5,7 @@ import * as Resources from "../utils/resources";
 import { handleJSONWithData } from "../utils/resources";
 import { normalizeString } from "../shared/utils/strings";
 import { forConstraint } from "../shared/validation/validator";
-import { Request, Response } from "express";
+import type { Request, Response } from "express";
 import {
     isMonitoringToken,
     JSONObject,
diff --git a/server/resources/nodeResource.ts b/server/resources/nodeResource.ts
index 2f1808f..10b6d62 100644
--- a/server/resources/nodeResource.ts
+++ b/server/resources/nodeResource.ts
@@ -6,7 +6,7 @@ import { normalizeMac, normalizeString } from "../shared/utils/strings";
 import { forConstraint, forConstraints } from "../shared/validation/validator";
 import * as Resources from "../utils/resources";
 import { handleJSONWithData } from "../utils/resources";
-import { Request, Response } from "express";
+import type { Request, Response } from "express";
 import {
     CreateOrUpdateNode,
     DomainSpecificNodeResponse,
diff --git a/server/resources/taskResource.ts b/server/resources/taskResource.ts
index dfadc96..feb03f6 100644
--- a/server/resources/taskResource.ts
+++ b/server/resources/taskResource.ts
@@ -5,7 +5,7 @@ import { handleJSONWithData, RequestData } from "../utils/resources";
 import { getTasks, Task } from "../jobs/scheduler";
 import { normalizeString } from "../shared/utils/strings";
 import { forConstraint } from "../shared/validation/validator";
-import { Request, Response } from "express";
+import type { Request, Response } from "express";
 import {
     isString,
     isTaskSortField,
diff --git a/server/services/mailService.ts b/server/services/mailService.ts
index 351f791..6cca5c4 100644
--- a/server/services/mailService.ts
+++ b/server/services/mailService.ts
@@ -4,7 +4,7 @@ import { db } from "../db/database";
 import Logger from "../logger";
 import * as MailTemplateService from "./mailTemplateService";
 import * as Resources from "../utils/resources";
-import { RestParams } from "../utils/resources";
+import type { RestParams } from "../utils/resources";
 import {
     EmailAddress,
     isJSONObject,
diff --git a/server/services/mailTemplateService.ts b/server/services/mailTemplateService.ts
index 9605115..2dbe15f 100644
--- a/server/services/mailTemplateService.ts
+++ b/server/services/mailTemplateService.ts
@@ -7,8 +7,8 @@ import { htmlToText } from "nodemailer-html-to-text";
 import { config } from "../config";
 import Logger from "../logger";
 import { editNodeUrl } from "../utils/urlBuilder";
-import { Transporter } from "nodemailer";
-import { MailData, Mail } from "../types";
+import type { Transporter } from "nodemailer";
+import type { MailData, Mail } from "../types";
 
 const templateBasePath = __dirname + "/../mailTemplates";
 const snippetsBasePath = templateBasePath + "/snippets";
diff --git a/server/services/monitoringService.test.ts b/server/services/monitoringService.test.ts
index cbb8e59..241d1e9 100644
--- a/server/services/monitoringService.test.ts
+++ b/server/services/monitoringService.test.ts
@@ -1,7 +1,7 @@
 import { ParsedNode, parseNode, parseNodesJson } from "./monitoringService";
 import { Domain, MAC, OnlineState, Site, UnixTimestampSeconds } from "../types";
 import Logger from "../logger";
-import { MockLogger } from "../__mocks__/logger";
+import type { MockLogger } from "../__mocks__/logger";
 import { now, parseTimestamp } from "../utils/time";
 
 const mockedLogger = Logger as MockLogger;
diff --git a/server/services/monitoringService.ts b/server/services/monitoringService.ts
index a8dd83e..57c915a 100644
--- a/server/services/monitoringService.ts
+++ b/server/services/monitoringService.ts
@@ -10,7 +10,7 @@ import Logger from "../logger";
 import * as MailService from "../services/mailService";
 import * as NodeService from "../services/nodeService";
 import * as Resources from "../utils/resources";
-import { RestParams } from "../utils/resources";
+import type { RestParams } from "../utils/resources";
 import { normalizeMac, parseInteger } from "../shared/utils/strings";
 import { monitoringDisableUrl } from "../utils/urlBuilder";
 import CONSTRAINTS from "../shared/validation/constraints";
diff --git a/server/shared/types/newtypes.ts b/server/shared/types/newtypes.ts
index d62b876..144c0c0 100644
--- a/server/shared/types/newtypes.ts
+++ b/server/shared/types/newtypes.ts
@@ -140,3 +140,15 @@ export type Domain = string & { readonly __tag: unique symbol };
  * @param arg - Value to check.
  */
 export const isDomain = toIsNewtype(isString, "" as Domain);
+
+/**
+ * A search term entered by the user in the frontend.
+ */
+export type SearchTerm = string & { readonly __tag: unique symbol };
+
+/**
+ * Type guard for {@link Domain}.
+ *
+ * @param arg - Value to check.
+ */
+export const isSearchTerm = isString;
diff --git a/server/tsconfig.json b/server/tsconfig.json
index 9abae53..9359523 100644
--- a/server/tsconfig.json
+++ b/server/tsconfig.json
@@ -19,8 +19,9 @@
     // "removeComments": true,                /* Do not emit comments to output. */
     // "noEmit": true,                        /* Do not emit outputs. */
     // "importHelpers": true,                 /* Import emit helpers from 'tslib'. */
+    "importsNotUsedAsValues": "error",        /* Enforce using `import type` instead of `import` for types */
     // "downlevelIteration": true,            /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
-    // "isolatedModules": true,               /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
+    "isolatedModules": true,                  /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
 
     /* Strict Type-Checking Options */
     "strict": true,                           /* Enable all strict type-checking options. */
@@ -29,7 +30,7 @@
     // "strictFunctionTypes": true,           /* Enable strict checking of function types. */
     // "strictBindCallApply": true,           /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
     // "strictPropertyInitialization": true,  /* Enable strict checking of property initialization in classes. */
-    // "noImplicitThis": true,                /* Raise error on 'this' expressions with an implied 'any' type. */
+    "noImplicitThis": true,                   /* Raise error on 'this' expressions with an implied 'any' type. */
     // "alwaysStrict": true,                  /* Parse in strict mode and emit "use strict" for each source file. */
 
     /* Additional Checks */
diff --git a/server/utils/resources.ts b/server/utils/resources.ts
index 4ebcbbf..1600acc 100644
--- a/server/utils/resources.ts
+++ b/server/utils/resources.ts
@@ -9,7 +9,7 @@ import {
     isConstraints,
     NestedConstraints,
 } from "../shared/validation/validator";
-import { Request, Response } from "express";
+import type { Request, Response } from "express";
 import {
     type GenericSortField,
     isJSONObject,
diff --git a/server/utils/urlBuilder.ts b/server/utils/urlBuilder.ts
index e2888d6..0e6a6f3 100644
--- a/server/utils/urlBuilder.ts
+++ b/server/utils/urlBuilder.ts
@@ -1,5 +1,5 @@
 import { config } from "../config";
-import { MonitoringToken, Url } from "../types";
+import type { MonitoringToken, Url } from "../types";
 
 function formUrl(route: string, queryParams?: { [key: string]: string }): Url {
     let url = config.server.baseUrl as string;