diff --git a/lib/server/prices.ts b/lib/server/prices.ts
index 143fa99..5ad3c79 100644
--- a/lib/server/prices.ts
+++ b/lib/server/prices.ts
@@ -1,3 +1,5 @@
+import { normalizeTicker } from '@/lib/server/utils';
+
 const YAHOO_BASE = 'https://query1.finance.yahoo.com/v8/finance/chart';
 const QUOTE_CACHE_TTL_MS = 1000 * 60;
 const PRICE_HISTORY_CACHE_TTL_MS = 1000 * 60 * 15;
@@ -27,11 +29,11 @@ const quoteCache = new Map<string, QuoteCacheEntry>();
 const priceHistoryCache = new Map<string, PriceHistoryCacheEntry>();
 
 function buildYahooChartUrl(ticker: string, params: string) {
-  return `${YAHOO_BASE}/${encodeURIComponent(ticker.trim().toUpperCase())}?${params}`;
+  return `${YAHOO_BASE}/${encodeURIComponent(normalizeTicker(ticker))}?${params}`;
 }
 
 export async function getQuote(ticker: string): Promise<QuoteResult> {
-  const normalizedTicker = ticker.trim().toUpperCase();
+  const normalizedTicker = normalizeTicker(ticker);
   const cached = quoteCache.get(normalizedTicker);
 
   if (cached && cached.expiresAt > Date.now()) {
@@ -101,7 +103,7 @@ export async function getQuoteOrNull(ticker: string): Promise<number | null> {
 }
 
 export async function getHistoricalClosingPrices(ticker: string, dates: string[]) {
-  const normalizedTicker = ticker.trim().toUpperCase();
+  const normalizedTicker = normalizeTicker(ticker);
   const normalizedDates = dates
     .map((value) => {
       const parsed = Date.parse(value);
@@ -169,7 +171,7 @@ export async function getHistoricalClosingPrices(ticker: string, dates: string[]
 }
 
 export async function getPriceHistory(ticker: string): Promise<PriceHistoryResult> {
-  const normalizedTicker = ticker.trim().toUpperCase();
+  const normalizedTicker = normalizeTicker(ticker);
   const cached = priceHistoryCache.get(normalizedTicker);
 
   if (cached && cached.expiresAt > Date.now()) {
diff --git a/lib/server/recent-developments.ts b/lib/server/recent-developments.ts
index a72cc60..7ec3ce9 100644
--- a/lib/server/recent-developments.ts
+++ b/lib/server/recent-developments.ts
@@ -1,5 +1,6 @@
 import { format } from 'date-fns';
 import type { Filing, RecentDevelopmentItem, RecentDevelopments } from '@/lib/types';
+import { normalizeTicker } from '@/lib/server/utils';
 
 export type RecentDevelopmentSourceContext = {
   filings: Filing[];
@@ -115,9 +116,9 @@ export async function getRecentDevelopments(
     limit?: number;
   }
 ): Promise<RecentDevelopments> {
-  const normalizedTicker = ticker.trim().toUpperCase();
+  const normalizedTicker = normalizeTicker(ticker);
   const limit = options?.limit ?? 6;
-  const cacheKey = `${normalizedTicker}:${context.filings.map((filing) => filing.accession_number).join(',')}`;
+  const cacheKey = `${normalizedTicker ?? ''}:${context.filings.map((filing) => filing.accession_number).join(',')}`;
   const cached = recentDevelopmentsCache.get(cacheKey);
 
   if (cached && cached.expiresAt > Date.now()) {
@@ -128,7 +129,7 @@ export async function getRecentDevelopments(
   const itemCollections = await Promise.all(
     sources.map(async (source) => {
       try {
-        return await source.fetch(normalizedTicker, context);
+        return await source.fetch(normalizedTicker ?? '', context);
       } catch {
         return [] satisfies RecentDevelopmentItem[];
       }
diff --git a/lib/server/repos/filings.ts b/lib/server/repos/filings.ts
index 9870172..4f64fc4 100644
--- a/lib/server/repos/filings.ts
+++ b/lib/server/repos/filings.ts
@@ -2,6 +2,7 @@ import { desc, eq, inArray, max } from 'drizzle-orm';
 import type { Filing } from '@/lib/types';
 import { db } from '@/lib/server/db';
 import { filing, filingLink } from '@/lib/server/db/schema';
+import { normalizeTicker, nowIso } from '@/lib/server/utils';
 
 type FilingRow = typeof filing.$inferSelect;
 
@@ -90,7 +91,7 @@ export async function getFilingByAccession(accessionNumber: string) {
 export async function listLatestFilingDatesByTickers(tickers: string[]) {
   const normalizedTickers = [...new Set(
     tickers
-      .map((ticker) => ticker.trim().toUpperCase())
+      .map((ticker) => normalizeTicker(ticker))
       .filter((ticker) => ticker.length > 0)
   )];
 
@@ -121,7 +122,7 @@ export async function upsertFilingsRecords(items: UpsertFilingInput[]) {
   let updated = 0;
 
   for (const item of items) {
-    const now = new Date().toISOString();
+    const now = nowIso();
 
     const existing = await getFilingByAccession(item.accession_number);
 
@@ -192,7 +193,7 @@ export async function saveFilingAnalysis(
     .update(filing)
     .set({
       analysis,
-      updated_at: new Date().toISOString()
+      updated_at: nowIso()
     })
     .where(eq(filing.accession_number, accessionNumber))
     .returning();
@@ -208,7 +209,7 @@ export async function updateFilingMetricsById(
     .update(filing)
     .set({
       metrics,
-      updated_at: new Date().toISOString()
+      updated_at: nowIso()
     })
     .where(eq(filing.id, filingId))
     .returning();
diff --git a/lib/server/repos/holdings.ts b/lib/server/repos/holdings.ts
index 64e5f36..a5a6fa3 100644
--- a/lib/server/repos/holdings.ts
+++ b/lib/server/repos/holdings.ts
@@ -3,6 +3,7 @@ import type { Holding } from '@/lib/types';
 import { recalculateHolding } from '@/lib/server/portfolio';
 import { db } from '@/lib/server/db';
 import { filing, holding, watchlistItem } from '@/lib/server/db/schema';
+import { normalizeTicker, nowIso } from '@/lib/server/utils';
 
 type HoldingRow = typeof holding.$inferSelect;
 
@@ -30,7 +31,7 @@ function sortByMarketValueDesc(rows: Holding[]) {
 
 function normalizeHoldingInput(input: { ticker: string; shares: number; avgCost: number; currentPrice: number }) {
   return {
-    ticker: input.ticker.trim().toUpperCase(),
+    ticker: normalizeTicker(input.ticker),
     shares: input.shares.toFixed(6),
     avg_cost: input.avgCost.toFixed(6),
     current_price: input.currentPrice.toFixed(6)
@@ -82,7 +83,7 @@ export async function listUserHoldings(userId: string) {
 }
 
 export async function getHoldingByTicker(userId: string, ticker: string) {
-  const normalizedTicker = ticker.trim().toUpperCase();
+  const normalizedTicker = normalizeTicker(ticker);
   if (!normalizedTicker) {
     return null;
   }
@@ -104,8 +105,8 @@ export async function upsertHoldingRecord(input: {
   currentPrice?: number;
   companyName?: string;
 }) {
-  const ticker = input.ticker.trim().toUpperCase();
-  const now = new Date().toISOString();
+  const ticker = normalizeTicker(input.ticker);
+  const now = nowIso();
 
   const [existing] = await db
     .select()
@@ -251,8 +252,8 @@ export async function updateHoldingByIdRecord(input: {
     shares: shares.toFixed(6),
     avg_cost: avgCost.toFixed(6),
     current_price: currentPrice.toFixed(6),
-    updated_at: new Date().toISOString(),
-    last_price_at: new Date().toISOString()
+    updated_at: nowIso(),
+    last_price_at: nowIso()
   });
 
   const [updated] = await db
diff --git a/lib/server/repos/research-library.ts b/lib/server/repos/research-library.ts
index a6f8ea0..05862a2 100644
--- a/lib/server/repos/research-library.ts
+++ b/lib/server/repos/research-library.ts
@@ -27,6 +27,14 @@ import {
 } from '@/lib/server/db/schema';
 import { getFilingByAccession, listFilingsRecords } from '@/lib/server/repos/filings';
 import { getWatchlistItemByTicker } from '@/lib/server/repos/watchlist';
+import {
+  normalizeTicker,
+  normalizeTags,
+  normalizeOptionalString,
+  normalizeRecord,
+  normalizePositiveInteger,
+  nowIso
+} from '@/lib/server/utils';
 
 type ResearchArtifactRow = typeof researchArtifact.$inferSelect;
 type ResearchMemoRow = typeof researchMemo.$inferSelect;
@@ -51,55 +59,6 @@ const RESEARCH_PACKET_SECTION_TITLES: Record<ResearchMemoSection, string> = {
   next_actions: 'Next Actions'
 };
 
-function normalizeTicker(ticker: string) {
-  return ticker.trim().toUpperCase();
-}
-
-function normalizeOptionalString(value?: string | null) {
-  const normalized = value?.trim();
-  return normalized ? normalized : null;
-}
-
-function normalizePositiveInteger(value?: number | null) {
-  if (value === null || value === undefined || !Number.isFinite(value)) {
-    return null;
-  }
-
-  const normalized = Math.trunc(value);
-  return normalized > 0 ? normalized : null;
-}
-
-function normalizeRecord(value?: Record<string, unknown> | null) {
-  if (!value || typeof value !== 'object' || Array.isArray(value)) {
-    return null;
-  }
-
-  return value;
-}
-
-function normalizeTags(tags?: string[] | null) {
-  if (!Array.isArray(tags)) {
-    return [];
-  }
-
-  const unique = new Set<string>();
-
-  for (const entry of tags) {
-    if (typeof entry !== 'string') {
-      continue;
-    }
-
-    const normalized = entry.trim();
-    if (!normalized) {
-      continue;
-    }
-
-    unique.add(normalized);
-  }
-
-  return [...unique];
-}
-
 function buildArtifactSearchText(input: {
   title?: string | null;
   summary?: string | null;
@@ -409,7 +368,7 @@ export async function createResearchArtifactRecord(input: {
     throw new Error('ticker is required');
   }
 
-  const now = new Date().toISOString();
+  const now = nowIso();
   const title = normalizeOptionalString(input.title);
   const summary = normalizeOptionalString(input.summary);
   const bodyMarkdown = normalizeOptionalString(input.bodyMarkdown);
@@ -520,7 +479,7 @@ export async function upsertSystemResearchArtifact(input: {
       search_text: searchText,
       tags: normalizeTags(input.tags),
       metadata: normalizeRecord(input.metadata),
-      updated_at: new Date().toISOString()
+      updated_at: nowIso()
     })
     .where(eq(researchArtifact.id, existing.id))
     .returning();
@@ -566,7 +525,7 @@ export async function updateResearchArtifactRecord(input: {
       metadata,
       tags,
       search_text: searchText,
-      updated_at: new Date().toISOString()
+      updated_at: nowIso()
     })
     .where(eq(researchArtifact.id, input.id))
     .returning();
@@ -702,7 +661,7 @@ export async function upsertResearchMemoRecord(input: {
     throw new Error('ticker is required');
   }
 
-  const now = new Date().toISOString();
+  const now = nowIso();
   const existing = await getResearchMemoByTicker(input.userId, ticker);
 
   if (!existing) {
@@ -796,7 +755,7 @@ export async function addResearchMemoEvidenceLink(input: {
       .then((rows) => (rows[0]?.maxOrder ?? 0) + 1)
     : Math.max(0, Math.trunc(input.sortOrder));
 
-  const now = new Date().toISOString();
+  const now = nowIso();
   if (existing.length > 0) {
     await db
       .update(researchMemoEvidence)
@@ -894,7 +853,7 @@ export async function getResearchPacket(userId: string, ticker: string): Promise
   return {
     ticker: normalizedTicker,
     companyName: coverage?.company_name ?? latestFiling?.company_name ?? null,
-    generated_at: new Date().toISOString(),
+    generated_at: nowIso(),
     memo,
     sections: toPacketSections(memo, evidenceBySection)
   };
diff --git a/lib/server/repos/tasks.ts b/lib/server/repos/tasks.ts
index 438c220..8e366c1 100644
--- a/lib/server/repos/tasks.ts
+++ b/lib/server/repos/tasks.ts
@@ -3,6 +3,7 @@ import type { Task, TaskStage, TaskStageContext, TaskStageEvent, TaskStatus, Tas
 import { db } from '@/lib/server/db';
 import { taskRun, taskStageEvent } from '@/lib/server/db/schema';
 import { buildTaskNotification } from '@/lib/server/task-notifications';
+import { nowIso } from '@/lib/server/utils';
 
 type TaskRow = typeof taskRun.$inferSelect;
 type TaskStageEventRow = typeof taskStageEvent.$inferSelect;
@@ -110,7 +111,7 @@ async function insertTaskStageEvent(executor: InsertExecutor, input: EventInsert
 }
 
 export async function createTaskRunRecord(input: CreateTaskInput) {
-  const now = new Date().toISOString();
+  const now = nowIso();
 
   return await db.transaction(async (tx) => {
     const [row] = await tx
@@ -219,7 +220,7 @@ async function attemptAtomicInsert(
 }
 
 export async function createTaskRunRecordAtomic(input: CreateTaskInput): Promise<AtomicCreateResult> {
-  const now = new Date().toISOString();
+  const now = nowIso();
 
   return await db.transaction(async (tx) => {
     const result = await attemptAtomicInsert(tx, input, now);
@@ -235,7 +236,7 @@ export async function setTaskWorkflowRunId(taskId: string, workflowRunId: string
     .update(taskRun)
     .set({
       workflow_run_id: workflowRunId,
-      updated_at: new Date().toISOString()
+      updated_at: nowIso()
     })
     .where(eq(taskRun.id, taskId));
 }
@@ -313,7 +314,7 @@ export async function findInFlightTaskByResourceKey(
 }
 
 export async function markTaskRunning(taskId: string) {
-  const now = new Date().toISOString();
+  const now = nowIso();
 
   return await db.transaction(async (tx) => {
     const [row] = await tx
@@ -354,7 +355,7 @@ export async function updateTaskStage(
   detail: string | null = null,
   context: TaskStageContext | null = null
 ) {
-  const now = new Date().toISOString();
+  const now = nowIso();
 
   return await db.transaction(async (tx) => {
     const [current] = await tx
@@ -403,7 +404,7 @@ export async function completeTask(
   result: Record<string, unknown>,
   completion: TaskCompletionState = {}
 ) {
-  const now = new Date().toISOString();
+  const now = nowIso();
 
   return await db.transaction(async (tx) => {
     const [row] = await tx
@@ -445,7 +446,7 @@ export async function markTaskFailure(
   stage: TaskStage = 'failed',
   failure: TaskCompletionState = {}
 ) {
-  const now = new Date().toISOString();
+  const now = nowIso();
 
   return await db.transaction(async (tx) => {
     const [row] = await tx
@@ -513,7 +514,7 @@ export async function setTaskStatusFromWorkflow(
       return toTask(current);
     }
 
-    const now = new Date().toISOString();
+    const now = nowIso();
     const [row] = await tx
       .update(taskRun)
       .set({
@@ -551,7 +552,7 @@ export async function updateTaskNotificationState(
   userId: string,
   input: UpdateTaskNotificationStateInput
 ) {
-  const now = new Date().toISOString();
+  const now = nowIso();
   const patch: Partial<typeof taskRun.$inferInsert> = {
     updated_at: now
   };
diff --git a/lib/server/repos/watchlist.ts b/lib/server/repos/watchlist.ts
index f718e28..45fe273 100644
--- a/lib/server/repos/watchlist.ts
+++ b/lib/server/repos/watchlist.ts
@@ -6,38 +6,12 @@ import type {
 } from '@/lib/types';
 import { db } from '@/lib/server/db';
 import { watchlistItem } from '@/lib/server/db/schema';
+import { normalizeTicker, normalizeTagsOrNull, nowIso } from '@/lib/server/utils';
 
 type WatchlistRow = typeof watchlistItem.$inferSelect;
 const DEFAULT_STATUS: CoverageStatus = 'backlog';
 const DEFAULT_PRIORITY: CoveragePriority = 'medium';
 
-function normalizeTags(tags?: string[]) {
-  if (!Array.isArray(tags)) {
-    return null;
-  }
-
-  const unique = new Set<string>();
-
-  for (const entry of tags) {
-    if (typeof entry !== 'string') {
-      continue;
-    }
-
-    const tag = entry.trim();
-    if (!tag) {
-      continue;
-    }
-
-    unique.add(tag);
-  }
-
-  if (unique.size === 0) {
-    return null;
-  }
-
-  return [...unique];
-}
-
 function toWatchlistItem(row: WatchlistRow, latestFilingDate: string | null = null): WatchlistItem {
   return {
     id: row.id,
@@ -79,7 +53,7 @@ export async function getWatchlistItemById(userId: string, id: number) {
 }
 
 export async function getWatchlistItemByTicker(userId: string, ticker: string) {
-  const normalizedTicker = ticker.trim().toUpperCase();
+  const normalizedTicker = normalizeTicker(ticker);
   if (!normalizedTicker) {
     return null;
   }
@@ -104,15 +78,15 @@ export async function upsertWatchlistItemRecord(input: {
   priority?: CoveragePriority;
   lastReviewedAt?: string | null;
 }) {
-  const normalizedTicker = input.ticker.trim().toUpperCase();
+  const normalizedTicker = normalizeTicker(input.ticker);
   const normalizedSector = input.sector?.trim() ? input.sector.trim() : null;
   const normalizedCategory = input.category?.trim() ? input.category.trim() : null;
-  const normalizedTags = normalizeTags(input.tags);
+  const normalizedTags = normalizeTagsOrNull(input.tags);
   const normalizedCompanyName = input.companyName.trim();
   const normalizedLastReviewedAt = input.lastReviewedAt?.trim()
     ? input.lastReviewedAt.trim()
     : null;
-  const now = new Date().toISOString();
+  const timestamp = nowIso();
 
   const [inserted] = await db
     .insert(watchlistItem)
@@ -125,8 +99,8 @@ export async function upsertWatchlistItemRecord(input: {
       tags: normalizedTags,
       status: input.status ?? DEFAULT_STATUS,
       priority: input.priority ?? DEFAULT_PRIORITY,
-      created_at: now,
-      updated_at: now,
+      created_at: timestamp,
+      updated_at: timestamp,
       last_reviewed_at: normalizedLastReviewedAt
     })
     .onConflictDoNothing({
@@ -156,7 +130,7 @@ export async function upsertWatchlistItemRecord(input: {
       tags: normalizedTags,
       status: input.status ?? existing?.status ?? DEFAULT_STATUS,
       priority: input.priority ?? existing?.priority ?? DEFAULT_PRIORITY,
-      updated_at: now,
+      updated_at: timestamp,
       last_reviewed_at: normalizedLastReviewedAt ?? existing?.last_reviewed_at ?? null
     })
     .where(and(eq(watchlistItem.user_id, input.userId), eq(watchlistItem.ticker, normalizedTicker)))
@@ -212,7 +186,7 @@ export async function updateWatchlistItemRecord(input: {
       : null;
   const nextTags = input.tags === undefined
     ? existing.tags ?? null
-    : normalizeTags(input.tags);
+    : normalizeTagsOrNull(input.tags);
   const nextLastReviewedAt = input.lastReviewedAt === undefined
     ? existing.last_reviewed_at
     : input.lastReviewedAt?.trim()
@@ -228,7 +202,7 @@ export async function updateWatchlistItemRecord(input: {
       tags: nextTags,
       status: input.status ?? existing.status ?? DEFAULT_STATUS,
       priority: input.priority ?? existing.priority ?? DEFAULT_PRIORITY,
-      updated_at: new Date().toISOString(),
+      updated_at: nowIso(),
       last_reviewed_at: nextLastReviewedAt
     })
     .where(and(eq(watchlistItem.user_id, input.userId), eq(watchlistItem.id, input.id)))
@@ -242,7 +216,7 @@ export async function updateWatchlistReviewByTicker(
   ticker: string,
   reviewedAt: string
 ) {
-  const normalizedTicker = ticker.trim().toUpperCase();
+  const normalizedTicker = normalizeTicker(ticker);
   if (!normalizedTicker) {
     return null;
   }
diff --git a/lib/server/search.ts b/lib/server/search.ts
index c2d327b..f6d198d 100644
--- a/lib/server/search.ts
+++ b/lib/server/search.ts
@@ -17,6 +17,7 @@ import {
   listResearchJournalEntries,
   listResearchJournalEntriesForUser
 } from '@/lib/server/repos/research-journal';
+import { normalizeTicker } from '@/lib/server/utils';
 
 type SearchDocumentScope = 'global' | 'user';
 type SearchDocumentSourceKind = 'filing_document' | 'filing_brief' | 'research_note';
@@ -131,11 +132,6 @@ function escapeLike(value: string) {
   return value.replace(/[%_]/g, (match) => `\\${match}`);
 }
 
-function normalizeTicker(value: string | null | undefined) {
-  const normalized = value?.trim().toUpperCase() ?? '';
-  return normalized.length > 0 ? normalized : null;
-}
-
 function normalizeSearchSources(sources?: SearchSource[]) {
   const normalized = new Set<SearchSource>();
 
diff --git a/lib/server/sec-company-profile.ts b/lib/server/sec-company-profile.ts
index eaee1ba..b6345d1 100644
--- a/lib/server/sec-company-profile.ts
+++ b/lib/server/sec-company-profile.ts
@@ -1,4 +1,5 @@
 import type { CompanyProfile, CompanyValuationSnapshot } from '@/lib/types';
+import { normalizeTicker } from '@/lib/server/utils';
 
 type FetchImpl = typeof fetch;
 
@@ -261,7 +262,7 @@ export async function getSecCompanyProfile(
   ticker: string,
   options?: { fetchImpl?: FetchImpl }
 ): Promise<SecCompanyProfileResult | null> {
-  const normalizedTicker = ticker.trim().toUpperCase();
+  const normalizedTicker = normalizeTicker(ticker);
   if (!normalizedTicker) {
     return null;
   }
diff --git a/lib/server/task-processors.ts b/lib/server/task-processors.ts
index bef9308..a11dffb 100644
--- a/lib/server/task-processors.ts
+++ b/lib/server/task-processors.ts
@@ -39,6 +39,7 @@ import {
 } from '@/lib/server/sec';
 import { enqueueTask } from '@/lib/server/tasks';
 import { hydrateFilingTaxonomySnapshot } from '@/lib/server/taxonomy/engine';
+import { nowIso } from '@/lib/server/utils';
 
 const EXTRACTION_REQUIRED_KEYS = [
   'summary',
@@ -762,7 +763,7 @@ async function processSyncFilings(task: Task) {
       await deleteCompanyFinancialBundlesForTicker(filing.ticker);
       taxonomySnapshotsHydrated += 1;
     } catch (error) {
-      const now = new Date().toISOString();
+      const now = nowIso();
       await upsertFilingTaxonomySnapshot({
         filing_id: filing.id,
         ticker: filing.ticker,
@@ -961,7 +962,7 @@ async function processRefreshPrices(task: Task) {
       }
     }
   );
-  const updatedCount = await applyRefreshedPrices(userId, quotes, new Date().toISOString());
+  const updatedCount = await applyRefreshedPrices(userId, quotes, nowIso());
 
   const result = {
     updatedCount,
diff --git a/lib/server/utils/index.ts b/lib/server/utils/index.ts
new file mode 100644
index 0000000..1218640
--- /dev/null
+++ b/lib/server/utils/index.ts
@@ -0,0 +1,20 @@
+export {
+  normalizeTicker,
+  normalizeTickerOrNull,
+  normalizeTags,
+  normalizeTagsOrNull,
+  normalizeOptionalString,
+  normalizeRecord,
+  normalizePositiveInteger,
+  nowIso,
+  todayIso
+} from './normalize';
+
+export {
+  asRecord,
+  asOptionalRecord,
+  asPositiveNumber,
+  asBoolean,
+  asStringArray,
+  asEnum
+} from './validation';
diff --git a/lib/server/utils/normalize.ts b/lib/server/utils/normalize.ts
new file mode 100644
index 0000000..ac6c607
--- /dev/null
+++ b/lib/server/utils/normalize.ts
@@ -0,0 +1,51 @@
+export function normalizeTicker(ticker: string): string {
+  return ticker.trim().toUpperCase();
+}
+
+export function normalizeTickerOrNull(ticker: unknown): string | null {
+  if (typeof ticker !== 'string') return null;
+  const normalized = ticker.trim().toUpperCase();
+  return normalized || null;
+}
+
+export function normalizeTags(tags?: unknown): string[] {
+  if (!Array.isArray(tags)) return [];
+
+  const unique = new Set<string>();
+  for (const entry of tags) {
+    if (typeof entry !== 'string') continue;
+    const tag = entry.trim();
+    if (tag) unique.add(tag);
+  }
+  return [...unique];
+}
+
+export function normalizeTagsOrNull(tags?: unknown): string[] | null {
+  const result = normalizeTags(tags);
+  return result.length > 0 ? result : null;
+}
+
+export function normalizeOptionalString(value?: unknown): string | null {
+  if (typeof value !== 'string') return null;
+  const normalized = value.trim();
+  return normalized || null;
+}
+
+export function normalizeRecord(value?: unknown): Record<string, unknown> | null {
+  if (!value || typeof value !== 'object' || Array.isArray(value)) return null;
+  return value as Record<string, unknown>;
+}
+
+export function normalizePositiveInteger(value?: unknown): number | null {
+  if (value === null || value === undefined || !Number.isFinite(value as number)) return null;
+  const normalized = Math.trunc(value as number);
+  return normalized > 0 ? normalized : null;
+}
+
+export function nowIso(): string {
+  return new Date().toISOString();
+}
+
+export function todayIso(): string {
+  return new Date().toISOString().slice(0, 10);
+}
diff --git a/lib/server/utils/validation.ts b/lib/server/utils/validation.ts
new file mode 100644
index 0000000..08c2d64
--- /dev/null
+++ b/lib/server/utils/validation.ts
@@ -0,0 +1,56 @@
+export function asRecord(value: unknown): Record<string, unknown> {
+  if (!value || typeof value !== 'object' || Array.isArray(value)) {
+    return {};
+  }
+  return value as Record<string, unknown>;
+}
+
+export function asOptionalRecord(value: unknown): Record<string, unknown> | null {
+  if (!value || typeof value !== 'object' || Array.isArray(value)) {
+    return null;
+  }
+  return value as Record<string, unknown>;
+}
+
+export function asPositiveNumber(value: unknown): number | null {
+  const parsed = typeof value === 'number' ? value : Number(value);
+  return Number.isFinite(parsed) && parsed > 0 ? parsed : null;
+}
+
+export function asBoolean(value: unknown, fallback = false): boolean {
+  if (typeof value === 'boolean') {
+    return value;
+  }
+
+  if (typeof value === 'string') {
+    const normalized = value.trim().toLowerCase();
+    if (normalized === 'true' || normalized === '1' || normalized === 'yes') {
+      return true;
+    }
+    if (normalized === 'false' || normalized === '0' || normalized === 'no') {
+      return false;
+    }
+  }
+
+  return fallback;
+}
+
+export function asStringArray(value: unknown): string[] {
+  const source = Array.isArray(value)
+    ? value
+    : typeof value === 'string'
+      ? value.split(',')
+      : [];
+
+  const unique = new Set<string>();
+  for (const entry of source) {
+    if (typeof entry !== 'string') continue;
+    const tag = entry.trim();
+    if (tag) unique.add(tag);
+  }
+  return [...unique];
+}
+
+export function asEnum<T extends string>(value: unknown, allowed: readonly T[]): T | undefined {
+  return allowed.includes(value as T) ? (value as T) : undefined;
+}
diff --git a/lib/server/yahoo-company-profile.ts b/lib/server/yahoo-company-profile.ts
index 944de1a..44e96d8 100644
--- a/lib/server/yahoo-company-profile.ts
+++ b/lib/server/yahoo-company-profile.ts
@@ -1,3 +1,5 @@
+import { normalizeTicker } from '@/lib/server/utils';
+
 type FetchImpl = typeof fetch;
 
 type CacheEntry<T> = {
@@ -142,7 +144,7 @@ export async function getYahooCompanyDescription(
   ticker: string,
   options?: { fetchImpl?: FetchImpl }
 ) {
-  const normalizedTicker = ticker.trim().toUpperCase();
+  const normalizedTicker = normalizeTicker(ticker);
   if (!normalizedTicker) {
     return null;
   }