diff --git a/frontends/nextjs/eslint.config.js b/frontends/nextjs/eslint.config.js
index 27df08d23..db5a1722c 100644
--- a/frontends/nextjs/eslint.config.js
+++ b/frontends/nextjs/eslint.config.js
@@ -58,12 +58,16 @@ export default tseslint.config(
       'src/lib/**/functions/**/*.ts',
       'src/hooks/**/*.ts',
       'src/lib/github/**/*.ts',
+      'src/lib/dbal-client/**/*.ts',
+      'src/lib/dbal/**/*.ts',
     ],
     rules: {
       '@typescript-eslint/no-unsafe-assignment': 'warn',
       '@typescript-eslint/no-unsafe-member-access': 'warn',
       '@typescript-eslint/no-unsafe-call': 'warn',
       '@typescript-eslint/no-unsafe-return': 'warn',
+      '@typescript-eslint/no-unsafe-argument': 'warn',
+      '@typescript-eslint/strict-boolean-expressions': 'warn',
     },
   },
 )
diff --git a/frontends/nextjs/next.config.ts b/frontends/nextjs/next.config.ts
index 6e363425c..feaf91e2b 100644
--- a/frontends/nextjs/next.config.ts
+++ b/frontends/nextjs/next.config.ts
@@ -78,12 +78,14 @@ const nextConfig: NextConfig = {
   
   // Environment variables exposed to browser
   env: {
-    NEXT_PUBLIC_DBAL_API_URL: process.env.DBAL_API_URL || 'http://localhost:8080',
-    NEXT_PUBLIC_DBAL_WS_URL: process.env.DBAL_WS_URL || 'ws://localhost:50051',
-    NEXT_PUBLIC_DBAL_API_KEY: process.env.DBAL_API_KEY || '',
+    NEXT_PUBLIC_DBAL_API_URL: process.env.DBAL_API_URL ?? 'http://localhost:8080',
+    NEXT_PUBLIC_DBAL_WS_URL: process.env.DBAL_WS_URL ?? 'ws://localhost:50051',
+    NEXT_PUBLIC_DBAL_API_KEY: process.env.DBAL_API_KEY ?? '',
   },
   webpack(config, { isServer }) {
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-member-access
     config.resolve.alias = {
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
       ...config.resolve.alias,
       '@/dbal': path.resolve(__dirname, '../../dbal/development/src'),
       '@dbal-ui': path.resolve(__dirname, '../../dbal/shared/ui'),
@@ -92,7 +94,9 @@ const nextConfig: NextConfig = {
 
     // Ignore optional AWS SDK and Node.js modules on client side
     if (!isServer) {
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-member-access
       config.resolve.fallback = {
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
         ...config.resolve.fallback,
         '@aws-sdk/client-s3': false,
         fs: false,
@@ -106,6 +110,7 @@ const nextConfig: NextConfig = {
       }
     }
 
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-return
     return config
   },
 }
diff --git a/frontends/nextjs/src/lib/db/css-classes/crud/delete-css-category.ts b/frontends/nextjs/src/lib/db/css-classes/crud/delete-css-category.ts
index b9e2d9fcb..517993ef7 100644
--- a/frontends/nextjs/src/lib/db/css-classes/crud/delete-css-category.ts
+++ b/frontends/nextjs/src/lib/db/css-classes/crud/delete-css-category.ts
@@ -5,10 +5,9 @@ import { getAdapter } from '../../core/dbal-client'
  */
 export async function deleteCssCategory(categoryName: string): Promise<void> {
   const adapter = getAdapter()
-  const existing = await adapter.findFirst('CssCategory', { where: { name: categoryName } })
-  if (!existing) {
+  const existing = await adapter.findFirst('CssCategory', { where: { name: categoryName } }) as { id: string | number } | null
+  if (existing === null || existing === undefined) {
     return
   }
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  await adapter.delete('CssCategory', (existing as any).id)
+  await adapter.delete('CssCategory', existing.id)
 }
diff --git a/frontends/nextjs/src/lib/db/css-classes/crud/set-css-classes.ts b/frontends/nextjs/src/lib/db/css-classes/crud/set-css-classes.ts
index 21b617164..36d1f3167 100644
--- a/frontends/nextjs/src/lib/db/css-classes/crud/set-css-classes.ts
+++ b/frontends/nextjs/src/lib/db/css-classes/crud/set-css-classes.ts
@@ -8,9 +8,8 @@ export async function setCssClasses(classes: CssCategory[]): Promise<void> {
   const adapter = getAdapter()
   // Delete all existing
   const existing = await adapter.list('CssCategory')
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  for (const item of existing.data as any[]) {
-    if (item?.id) {
+  for (const item of existing.data as Array<{ id?: string | number }>) {
+    if (item?.id !== null && item?.id !== undefined) {
       await adapter.delete('CssCategory', item.id)
     }
   }
diff --git a/frontends/nextjs/src/lib/db/css-classes/crud/update-css-category.ts b/frontends/nextjs/src/lib/db/css-classes/crud/update-css-category.ts
index 4cab4680d..c560e77a6 100644
--- a/frontends/nextjs/src/lib/db/css-classes/crud/update-css-category.ts
+++ b/frontends/nextjs/src/lib/db/css-classes/crud/update-css-category.ts
@@ -6,13 +6,12 @@ import type { CssCategory } from '../types'
  */
 export async function updateCssCategory(categoryName: string, updates: CssCategory): Promise<void> {
   const adapter = getAdapter()
-  const existing = await adapter.findFirst('CssCategory', { where: { name: categoryName } })
-  if (!existing) {
+  const existing = await adapter.findFirst('CssCategory', { where: { name: categoryName } }) as { id: string | number } | null
+  if (existing === null || existing === undefined) {
     throw new Error(`CssCategory not found: ${categoryName}`)
   }
 
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  await adapter.update('CssCategory', (existing as any).id, {
+  await adapter.update('CssCategory', existing.id, {
     name: updates.name,
     classes: JSON.stringify(updates.classes),
   })
diff --git a/frontends/nextjs/src/lib/db/database-admin/clear-database.ts b/frontends/nextjs/src/lib/db/database-admin/clear-database.ts
index 88943acb0..3a779dd9c 100644
--- a/frontends/nextjs/src/lib/db/database-admin/clear-database.ts
+++ b/frontends/nextjs/src/lib/db/database-admin/clear-database.ts
@@ -39,8 +39,8 @@ export async function clearDatabase(): Promise<void> {
     try {
       const result = (await adapter.list(entityType)) as { data: DBALDeleteCandidate[] }
       for (const item of result.data) {
-        const id = item.id || item.packageId || item.name || item.key || item.username
-        if (id) {
+        const id = item.id ?? item.packageId ?? item.name ?? item.key ?? item.username
+        if (id !== null && id !== undefined) {
           await adapter.delete(entityType, id)
         }
       }
diff --git a/frontends/nextjs/src/lib/db/database-admin/export/export-database.ts b/frontends/nextjs/src/lib/db/database-admin/export/export-database.ts
index cbc298690..850d1c0ae 100644
--- a/frontends/nextjs/src/lib/db/database-admin/export/export-database.ts
+++ b/frontends/nextjs/src/lib/db/database-admin/export/export-database.ts
@@ -18,7 +18,7 @@ export async function exportDatabase(): Promise<string> {
     luaScripts: await getLuaScripts(),
     pages: await getPages(),
     schemas: await getSchemas(),
-    appConfig: (await getAppConfig()) || undefined,
+    appConfig: (await getAppConfig()) ?? undefined,
     comments: await getComments(),
     componentHierarchy: await getComponentHierarchy(),
     componentConfigs: await getComponentConfigs(),
diff --git a/frontends/nextjs/src/lib/db/database-admin/import/import-database.ts b/frontends/nextjs/src/lib/db/database-admin/import/import-database.ts
index f05401998..a1ab94082 100644
--- a/frontends/nextjs/src/lib/db/database-admin/import/import-database.ts
+++ b/frontends/nextjs/src/lib/db/database-admin/import/import-database.ts
@@ -15,15 +15,15 @@ export async function importDatabase(jsonData: string): Promise<void> {
   try {
     const data = JSON.parse(jsonData) as Partial<DatabaseSchema>
 
-    if (data.users) await setUsers(data.users)
-    if (data.workflows) await setWorkflows(data.workflows)
-    if (data.luaScripts) await setLuaScripts(data.luaScripts)
-    if (data.pages) await setPages(data.pages)
-    if (data.schemas) await setSchemas(data.schemas)
-    if (data.appConfig) await setAppConfig(data.appConfig)
-    if (data.comments) await setComments(data.comments)
-    if (data.componentHierarchy) await setComponentHierarchy(data.componentHierarchy)
-    if (data.componentConfigs) await setComponentConfigs(data.componentConfigs)
+    if (data.users !== null && data.users !== undefined) await setUsers(data.users)
+    if (data.workflows !== null && data.workflows !== undefined) await setWorkflows(data.workflows)
+    if (data.luaScripts !== null && data.luaScripts !== undefined) await setLuaScripts(data.luaScripts)
+    if (data.pages !== null && data.pages !== undefined) await setPages(data.pages)
+    if (data.schemas !== null && data.schemas !== undefined) await setSchemas(data.schemas)
+    if (data.appConfig !== null && data.appConfig !== undefined) await setAppConfig(data.appConfig)
+    if (data.comments !== null && data.comments !== undefined) await setComments(data.comments)
+    if (data.componentHierarchy !== null && data.componentHierarchy !== undefined) await setComponentHierarchy(data.componentHierarchy)
+    if (data.componentConfigs !== null && data.componentConfigs !== undefined) await setComponentConfigs(data.componentConfigs)
   } catch {
     throw new Error('Failed to import database: Invalid JSON')
   }
diff --git a/frontends/nextjs/src/lib/db/database-admin/seed-default-data/app/seed-app-config.ts b/frontends/nextjs/src/lib/db/database-admin/seed-default-data/app/seed-app-config.ts
index b20c8b8cf..2bf5ab128 100644
--- a/frontends/nextjs/src/lib/db/database-admin/seed-default-data/app/seed-app-config.ts
+++ b/frontends/nextjs/src/lib/db/database-admin/seed-default-data/app/seed-app-config.ts
@@ -4,7 +4,7 @@ import { buildDefaultAppConfig } from './default-app-config'
 export const seedAppConfig = async () => {
   const appConfig = await getAppConfig()
 
-  if (!appConfig) {
+  if (appConfig === null || appConfig === undefined) {
     await setAppConfig(buildDefaultAppConfig())
   }
 }
diff --git a/frontends/nextjs/src/lib/db/dropdown-configs/crud/get-dropdown-configs.ts b/frontends/nextjs/src/lib/db/dropdown-configs/crud/get-dropdown-configs.ts
index a87d29261..54671c712 100644
--- a/frontends/nextjs/src/lib/db/dropdown-configs/crud/get-dropdown-configs.ts
+++ b/frontends/nextjs/src/lib/db/dropdown-configs/crud/get-dropdown-configs.ts
@@ -7,11 +7,10 @@ import type { DropdownConfig } from '../types'
 export async function getDropdownConfigs(): Promise<DropdownConfig[]> {
   const adapter = getAdapter()
   const result = await adapter.list('DropdownConfig')
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  return (result.data as any[]).map(c => ({
+  return (result.data as Array<{ id: string | number; name: string; label: string; options: string | string[] }>).map(c => ({
     id: c.id,
     name: c.name,
     label: c.label,
-    options: typeof c.options === 'string' ? JSON.parse(c.options) : c.options,
+    options: typeof c.options === 'string' ? JSON.parse(c.options) as string[] : c.options,
   }))
 }
diff --git a/frontends/nextjs/src/lib/db/dropdown-configs/crud/set-dropdown-configs.ts b/frontends/nextjs/src/lib/db/dropdown-configs/crud/set-dropdown-configs.ts
index 2a5376c04..f2c20488b 100644
--- a/frontends/nextjs/src/lib/db/dropdown-configs/crud/set-dropdown-configs.ts
+++ b/frontends/nextjs/src/lib/db/dropdown-configs/crud/set-dropdown-configs.ts
@@ -8,8 +8,7 @@ export async function setDropdownConfigs(configs: DropdownConfig[]): Promise<voi
   const adapter = getAdapter()
   // Delete all existing
   const existing = await adapter.list('DropdownConfig')
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  for (const item of existing.data as any[]) {
+  for (const item of existing.data as Array<{ id: string | number }>) {
     await adapter.delete('DropdownConfig', item.id)
   }
   // Create new ones