diff --git a/api/hooks/config-client.js b/api/hooks/config-client.js
index 6bf4857..3202557 100644
--- a/api/hooks/config-client.js
+++ b/api/hooks/config-client.js
@@ -6,7 +6,6 @@ const apiClientBaseURL = "/api/"
 
 const cryptchaSiteId = "6628f06a0938460001505119"
 
-// @ts-ignore
 if (release && typeof context !== "undefined") {
     context.response.header("X-Release", release)
     context.response.header("X-Build-Time", buildTime)
diff --git a/frontend/src/config.ts b/frontend/src/config.ts
index 174d88a..367dd1c 100644
--- a/frontend/src/config.ts
+++ b/frontend/src/config.ts
@@ -1,5 +1,4 @@
-// @ts-ignore
-import * as sentry from "./sentry"
+import * as sentry from "./sentry" // used when Sentry is enabled for deploy
 import configClient from "../../api/hooks/config-client"
 
 export const apiBaseURL = configClient.apiClientBaseURL
@@ -8,7 +7,7 @@ export const release = configClient.release
 export const sentryDSN = ""
 export const sentryTracingOrigins = ["localhost", "project-domain.tld", /^\//]
 export const sentryEnvironment: string = "local"
-// need to execute early for fetch wrapping
 // sentry.init(sentryDSN, sentryTracingOrigins, sentryEnvironment, release)
+void sentry // preserve import for deploy activation
 
 export const metricCall = false
diff --git a/frontend/src/lib/api.ts b/frontend/src/lib/api.ts
index d2ec715..d2c9bcb 100644
--- a/frontend/src/lib/api.ts
+++ b/frontend/src/lib/api.ts
@@ -20,19 +20,21 @@ import { checkBuildVersion } from "./versionCheck"
 // ---------------------------------------------------------------------------
 // Request deduplication
 // ---------------------------------------------------------------------------
-const pendingRequests = new Map<string, Promise<any>>()
+const pendingRequests = new Map<string, Promise<ApiResult<unknown>>>()
 
 /**
  * Generate a deterministic cache key for a request so identical parallel calls
  * collapse into a single network round-trip.
  */
-const getRequestCacheKey = (endpoint: string, options?: ApiOptions, body?: any): string => {
-    const deterministicStringify = (obj: any): string => {
+const getRequestCacheKey = (endpoint: string, options?: ApiOptions, body?: unknown): string => {
+    const deterministicStringify = (obj: unknown): string => {
         if (obj === null || obj === undefined) return String(obj)
         if (typeof obj !== "object") return JSON.stringify(obj)
         if (Array.isArray(obj)) return `[${obj.map(deterministicStringify).join(",")}]`
         const keys = Object.keys(obj).sort()
-        const pairs = keys.map((key) => `${JSON.stringify(key)}:${deterministicStringify(obj[key])}`)
+        const pairs = keys.map(
+            (key) => `${JSON.stringify(key)}:${deterministicStringify((obj as Record<string, unknown>)[key])}`
+        )
         return `{${pairs.join(",")}}`
     }
     return deterministicStringify({ endpoint, options, body })
@@ -56,7 +58,7 @@ const getRequestCacheKey = (endpoint: string, options?: ApiOptions, body?: any):
 export const api = async <T>(
     endpoint: string,
     options?: ApiOptions,
-    body?: any,
+    body?: unknown,
     signal?: AbortSignal
 ): Promise<ApiResult<T>> => {
     const _apiBaseOverride = get(apiBaseOverride) || ""
@@ -72,7 +74,7 @@ export const api = async <T>(
     // Deduplication: skip when caller provides a signal (they want explicit control)
     const cacheKey = getRequestCacheKey(endpoint, options, body)
     if (!signal && pendingRequests.has(cacheKey)) {
-        return pendingRequests.get(cacheKey)!
+        return pendingRequests.get(cacheKey) as Promise<ApiResult<T>>
     }
 
     const requestPromise = (async () => {
@@ -94,10 +96,10 @@ export const api = async <T>(
             return data as ApiResult<T>
         } catch (err) {
             // Don't send abort errors to Sentry
-            if ((err as any)?.name === "AbortError") throw err
+            if (err instanceof DOMException && err.name === "AbortError") throw err
 
             // Auth: 401 handling placeholder
-            // const status = (err as any)?.response?.status
+            // const status = (err as { response?: { status?: number } })?.response?.status
             // if (status === 401) { /* refresh token + retry */ }
 
             throw err
@@ -119,7 +121,7 @@ export const api = async <T>(
 // ---------------------------------------------------------------------------
 // In-memory response cache (for getCachedEntries / getCachedEntry)
 // ---------------------------------------------------------------------------
-const cache: { [key: string]: { expire: number; data: any } } = {}
+const cache: Record<string, { expire: number; data: unknown }> = {}
 const CACHE_TTL = 1000 * 60 * 60 // 1 hour
 
 // ---------------------------------------------------------------------------
@@ -132,16 +134,16 @@ type EntryTypeSwitch<T extends string> = T extends "medialib"
     ? MedialibEntry
     : T extends "content"
       ? ContentEntry
-      : Record<string, any>
+      : Record<string, unknown>
 
 export async function getDBEntries<T extends CollectionNameT>(
     collectionName: T,
-    filter?: { [key: string]: any },
+    filter?: MongoFilter,
     sort: string = "sort",
     limit?: number,
     offset?: number,
     projection?: string,
-    params?: { [key: string]: string }
+    params?: Record<string, string>
 ): Promise<EntryTypeSwitch<T>[]> {
     const c = await api<EntryTypeSwitch<T>[]>(collectionName, {
         filter,
@@ -156,16 +158,16 @@ export async function getDBEntries<T extends CollectionNameT>(
 
 export async function getCachedEntries<T extends CollectionNameT>(
     collectionName: T,
-    filter?: { [key: string]: any },
+    filter?: MongoFilter,
     sort: string = "sort",
     limit?: number,
     offset?: number,
     projection?: string,
-    params?: { [key: string]: string }
+    params?: Record<string, string>
 ): Promise<EntryTypeSwitch<T>[]> {
     const filterStr = obj2str({ collectionName, filter, sort, limit, offset, projection, params })
     if (cache[filterStr] && cache[filterStr].expire >= Date.now()) {
-        return cache[filterStr].data
+        return cache[filterStr].data as EntryTypeSwitch<T>[]
     }
     const entries = await getDBEntries<T>(collectionName, filter, sort, limit, offset, projection, params)
     cache[filterStr] = { expire: Date.now() + CACHE_TTL, data: entries }
@@ -174,20 +176,20 @@ export async function getCachedEntries<T extends CollectionNameT>(
 
 export async function getDBEntry<T extends CollectionNameT>(
     collectionName: T,
-    filter: { [key: string]: any },
+    filter: MongoFilter,
     projection?: string,
-    params?: { [key: string]: string }
-) {
-    return (await getDBEntries<T>(collectionName, filter, "_id", 1, null, projection, params))?.[0]
+    params?: Record<string, string>
+): Promise<EntryTypeSwitch<T> | undefined> {
+    return (await getDBEntries<T>(collectionName, filter, "_id", 1, undefined, projection, params))?.[0]
 }
 
 export async function getCachedEntry<T extends CollectionNameT>(
     collectionName: T,
-    filter: { [key: string]: any },
+    filter: MongoFilter,
     projection?: string,
-    params?: { [key: string]: string }
-) {
-    return (await getCachedEntries<T>(collectionName, filter, "_id", 1, null, projection, params))?.[0]
+    params?: Record<string, string>
+): Promise<EntryTypeSwitch<T> | undefined> {
+    return (await getCachedEntries<T>(collectionName, filter, "_id", 1, undefined, projection, params))?.[0]
 }
 
 export async function postDBEntry<T extends CollectionNameT>(
diff --git a/frontend/src/lib/store.ts b/frontend/src/lib/store.ts
index 739283c..f85e7a6 100644
--- a/frontend/src/lib/store.ts
+++ b/frontend/src/lib/store.ts
@@ -50,11 +50,7 @@ const publishLocation = (_p?: string) => {
 }
 
 if (typeof history !== "undefined") {
-    const historyApply = (
-        target: (this: any, ...args: readonly any[]) => unknown,
-        thisArg: any,
-        argumentsList: string | readonly any[]
-    ) => {
+    const historyApply: ProxyHandler<typeof history.pushState>["apply"] = (target, thisArg, argumentsList) => {
         publishLocation(argumentsList && argumentsList.length >= 2 && argumentsList[2])
         Reflect.apply(target, thisArg, argumentsList)
     }
diff --git a/frontend/src/lib/utils.ts b/frontend/src/lib/utils.ts
index 4dbff9b..54dc390 100644
--- a/frontend/src/lib/utils.ts
+++ b/frontend/src/lib/utils.ts
@@ -1,4 +1,7 @@
-export function debounce<T extends (...args: any[]) => void>(func: T, wait: number): (...args: Parameters<T>) => void {
+export function debounce<T extends (...args: never[]) => void>(
+    func: T,
+    wait: number
+): (...args: Parameters<T>) => void {
     let timeout: NodeJS.Timeout | null = null
 
     return (...args: Parameters<T>) => {
diff --git a/types/global.d.ts b/types/global.d.ts
index 2d6a68c..6cc0945 100644
--- a/types/global.d.ts
+++ b/types/global.d.ts
@@ -5,9 +5,12 @@ interface Ssr {
     // validUntil: any // go Time
 }
 
+/** MongoDB-style filter, e.g. { _id: "abc" } or { $or: [...] } */
+type MongoFilter = Record<string, unknown>
+
 interface ApiOptions {
     method?: "GET" | "POST" | "PUT" | "DELETE"
-    filter?: any
+    filter?: MongoFilter
     sort?: string
     lookup?: string
     limit?: number