diff --git a/deno.json b/deno.json
index 0225510..12fbb57 100644
--- a/deno.json
+++ b/deno.json
@@ -24,6 +24,7 @@
     "@sentry/deno": "https://deno.land/x/sentry@7.112.2/index.mjs",
     "@soapbox/kysely-deno-sqlite": "jsr:@soapbox/kysely-deno-sqlite@^2.1.0",
     "@soapbox/stickynotes": "jsr:@soapbox/stickynotes@^0.4.0",
+    "@std/assert": "jsr:@std/assert@^0.225.1",
     "@std/cli": "jsr:@std/cli@^0.223.0",
     "@std/crypto": "jsr:@std/crypto@^0.224.0",
     "@std/dotenv": "jsr:@std/dotenv@^0.224.0",
diff --git a/src/db.ts b/src/db.ts
deleted file mode 100644
index 1a5f06d..0000000
--- a/src/db.ts
+++ /dev/null
@@ -1,41 +0,0 @@
-import fs from 'node:fs/promises';
-import path from 'node:path';
-
-import { FileMigrationProvider, Migrator } from 'kysely';
-
-import { DittoDB } from '@/db/DittoDB.ts';
-
-const db = await DittoDB.getInstance();
-
-const migrator = new Migrator({
-  db,
-  provider: new FileMigrationProvider({
-    fs,
-    path,
-    migrationFolder: new URL(import.meta.resolve('./db/migrations')).pathname,
-  }),
-});
-
-/** Migrate the database to the latest version. */
-async function migrate() {
-  console.info('Running migrations...');
-  const results = await migrator.migrateToLatest();
-
-  if (results.error) {
-    console.error(results.error);
-    Deno.exit(1);
-  } else {
-    if (!results.results?.length) {
-      console.info('Everything up-to-date.');
-    } else {
-      console.info('Migrations finished!');
-      for (const { migrationName, status } of results.results!) {
-        console.info(`  - ${migrationName}: ${status}`);
-      }
-    }
-  }
-}
-
-await migrate();
-
-export { db };
diff --git a/src/db/DittoDB.ts b/src/db/DittoDB.ts
index abe068b..9c3b280 100644
--- a/src/db/DittoDB.ts
+++ b/src/db/DittoDB.ts
@@ -1,4 +1,7 @@
-import { Kysely } from 'kysely';
+import fs from 'node:fs/promises';
+import path from 'node:path';
+
+import { FileMigrationProvider, Kysely, Migrator } from 'kysely';
 
 import { Conf } from '@/config.ts';
 import { DittoPostgres } from '@/db/adapters/DittoPostgres.ts';
@@ -6,17 +9,63 @@ import { DittoSQLite } from '@/db/adapters/DittoSQLite.ts';
 import { DittoTables } from '@/db/DittoTables.ts';
 
 export class DittoDB {
+  private static kysely: Promise<Kysely<DittoTables>> | undefined;
+
   static getInstance(): Promise<Kysely<DittoTables>> {
+    if (!this.kysely) {
+      this.kysely = this._getInstance();
+    }
+    return this.kysely;
+  }
+
+  static async _getInstance(): Promise<Kysely<DittoTables>> {
     const { databaseUrl } = Conf;
 
+    let kysely: Kysely<DittoTables>;
+
     switch (databaseUrl.protocol) {
       case 'sqlite:':
-        return DittoSQLite.getInstance();
+        kysely = await DittoSQLite.getInstance();
+        break;
       case 'postgres:':
       case 'postgresql:':
-        return DittoPostgres.getInstance();
+        kysely = await DittoPostgres.getInstance();
+        break;
       default:
         throw new Error('Unsupported database URL.');
     }
+
+    await this.migrate(kysely);
+
+    return kysely;
+  }
+
+  /** Migrate the database to the latest version. */
+  private static async migrate(kysely: Kysely<DittoTables>) {
+    const migrator = new Migrator({
+      db: kysely,
+      provider: new FileMigrationProvider({
+        fs,
+        path,
+        migrationFolder: new URL(import.meta.resolve('../db/migrations')).pathname,
+      }),
+    });
+
+    console.info('Running migrations...');
+    const results = await migrator.migrateToLatest();
+
+    if (results.error) {
+      console.error(results.error);
+      Deno.exit(1);
+    } else {
+      if (!results.results?.length) {
+        console.info('Everything up-to-date.');
+      } else {
+        console.info('Migrations finished!');
+        for (const { migrationName, status } of results.results!) {
+          console.info(`  - ${migrationName}: ${status}`);
+        }
+      }
+    }
   }
 }
diff --git a/src/db/unattached-media.ts b/src/db/unattached-media.ts
index 960abe8..708e2f9 100644
--- a/src/db/unattached-media.ts
+++ b/src/db/unattached-media.ts
@@ -1,6 +1,6 @@
 import uuid62 from 'uuid62';
 
-import { db } from '@/db.ts';
+import { DittoDB } from '@/db/DittoDB.ts';
 import { type MediaData } from '@/schemas/nostr.ts';
 
 interface UnattachedMedia {
@@ -19,7 +19,8 @@ async function insertUnattachedMedia(media: Omit<UnattachedMedia, 'id' | 'upload
     ...media,
   };
 
-  await db.insertInto('unattached_media')
+  const kysely = await DittoDB.getInstance();
+  await kysely.insertInto('unattached_media')
     .values({ ...result, data: JSON.stringify(media.data) })
     .execute();
 
@@ -27,8 +28,9 @@ async function insertUnattachedMedia(media: Omit<UnattachedMedia, 'id' | 'upload
 }
 
 /** Select query for unattached media. */
-function selectUnattachedMediaQuery() {
-  return db.selectFrom('unattached_media')
+async function selectUnattachedMediaQuery() {
+  const kysely = await DittoDB.getInstance();
+  return kysely.selectFrom('unattached_media')
     .select([
       'unattached_media.id',
       'unattached_media.pubkey',
@@ -39,25 +41,27 @@ function selectUnattachedMediaQuery() {
 }
 
 /** Find attachments that exist but aren't attached to any events. */
-function getUnattachedMedia(until: Date) {
-  return selectUnattachedMediaQuery()
+async function getUnattachedMedia(until: Date) {
+  const query = await selectUnattachedMediaQuery();
+  return query
     .leftJoin('tags', 'unattached_media.url', 'tags.value')
     .where('uploaded_at', '<', until.getTime())
     .execute();
 }
 
 /** Delete unattached media by URL. */
-function deleteUnattachedMediaByUrl(url: string) {
-  return db.deleteFrom('unattached_media')
+async function deleteUnattachedMediaByUrl(url: string) {
+  const kysely = await DittoDB.getInstance();
+  return kysely.deleteFrom('unattached_media')
     .where('url', '=', url)
     .execute();
 }
 
 /** Get unattached media by IDs. */
-// deno-lint-ignore require-await
 async function getUnattachedMediaByIds(ids: string[]) {
   if (!ids.length) return [];
-  return selectUnattachedMediaQuery()
+  const query = await selectUnattachedMediaQuery();
+  return query
     .where('id', 'in', ids)
     .execute();
 }
@@ -65,7 +69,8 @@ async function getUnattachedMediaByIds(ids: string[]) {
 /** Delete rows as an event with media is being created. */
 async function deleteAttachedMedia(pubkey: string, urls: string[]): Promise<void> {
   if (!urls.length) return;
-  await db.deleteFrom('unattached_media')
+  const kysely = await DittoDB.getInstance();
+  await kysely.deleteFrom('unattached_media')
     .where('pubkey', '=', pubkey)
     .where('url', 'in', urls)
     .execute();
diff --git a/src/pipeline.ts b/src/pipeline.ts
index 9742b49..48e5c38 100644
--- a/src/pipeline.ts
+++ b/src/pipeline.ts
@@ -5,7 +5,7 @@ import Debug from '@soapbox/stickynotes/debug';
 import { sql } from 'kysely';
 
 import { Conf } from '@/config.ts';
-import { db } from '@/db.ts';
+import { DittoDB } from '@/db/DittoDB.ts';
 import { deleteAttachedMedia } from '@/db/unattached-media.ts';
 import { DittoEvent } from '@/interfaces/DittoEvent.ts';
 import { isEphemeralKind } from '@/kinds.ts';
@@ -91,7 +91,8 @@ async function encounterEvent(event: NostrEvent, signal: AbortSignal): Promise<b
 async function hydrateEvent(event: DittoEvent, signal: AbortSignal): Promise<void> {
   await hydrateEvents({ events: [event], store: await Storages.db(), signal });
 
-  const domain = await db
+  const kysely = await DittoDB.getInstance();
+  const domain = await kysely
     .selectFrom('pubkey_domains')
     .select('domain')
     .where('pubkey', '=', event.pubkey)
@@ -140,6 +141,7 @@ async function parseMetadata(event: NostrEvent, signal: AbortSignal): Promise<vo
 
   // Track pubkey domain.
   try {
+    const kysely = await DittoDB.getInstance();
     const { domain } = parseNip05(nip05);
 
     await sql`
@@ -149,7 +151,7 @@ async function parseMetadata(event: NostrEvent, signal: AbortSignal): Promise<vo
       domain = excluded.domain,
       last_updated_at = excluded.last_updated_at
     WHERE excluded.last_updated_at > pubkey_domains.last_updated_at
-    `.execute(db);
+    `.execute(kysely);
   } catch (_e) {
     // do nothing
   }
diff --git a/src/stats.ts b/src/stats.ts
index bff2aeb..f8efe16 100644
--- a/src/stats.ts
+++ b/src/stats.ts
@@ -2,7 +2,7 @@ import { NKinds, NostrEvent } from '@nostrify/nostrify';
 import Debug from '@soapbox/stickynotes/debug';
 import { InsertQueryBuilder } from 'kysely';
 
-import { db } from '@/db.ts';
+import { DittoDB } from '@/db/DittoDB.ts';
 import { DittoTables } from '@/db/DittoTables.ts';
 import { Storages } from '@/storages.ts';
 import { findReplyTag } from '@/tags.ts';
@@ -25,7 +25,7 @@ async function updateStats(event: NostrEvent) {
   if (event.kind === 3) {
     prev = await getPrevEvent(event);
     if (!prev || event.created_at >= prev.created_at) {
-      queries.push(updateFollowingCountQuery(event));
+      queries.push(await updateFollowingCountQuery(event));
     }
   }
 
@@ -37,8 +37,8 @@ async function updateStats(event: NostrEvent) {
     debug(JSON.stringify({ id: event.id, pubkey: event.pubkey, kind: event.kind, tags: event.tags, statDiffs }));
   }
 
-  if (pubkeyDiffs.length) queries.push(authorStatsQuery(pubkeyDiffs));
-  if (eventDiffs.length) queries.push(eventStatsQuery(eventDiffs));
+  if (pubkeyDiffs.length) queries.push(await authorStatsQuery(pubkeyDiffs));
+  if (eventDiffs.length) queries.push(await eventStatsQuery(eventDiffs));
 
   if (queries.length) {
     await Promise.all(queries.map((query) => query.execute()));
@@ -102,7 +102,7 @@ async function getStatsDiff(event: NostrEvent, prev: NostrEvent | undefined): Pr
 }
 
 /** Create an author stats query from the list of diffs. */
-function authorStatsQuery(diffs: AuthorStatDiff[]) {
+async function authorStatsQuery(diffs: AuthorStatDiff[]) {
   const values: DittoTables['author_stats'][] = diffs.map(([_, pubkey, stat, diff]) => {
     const row: DittoTables['author_stats'] = {
       pubkey,
@@ -114,7 +114,8 @@ function authorStatsQuery(diffs: AuthorStatDiff[]) {
     return row;
   });
 
-  return db.insertInto('author_stats')
+  const kysely = await DittoDB.getInstance();
+  return kysely.insertInto('author_stats')
     .values(values)
     .onConflict((oc) =>
       oc
@@ -128,7 +129,7 @@ function authorStatsQuery(diffs: AuthorStatDiff[]) {
 }
 
 /** Create an event stats query from the list of diffs. */
-function eventStatsQuery(diffs: EventStatDiff[]) {
+async function eventStatsQuery(diffs: EventStatDiff[]) {
   const values: DittoTables['event_stats'][] = diffs.map(([_, event_id, stat, diff]) => {
     const row: DittoTables['event_stats'] = {
       event_id,
@@ -140,7 +141,8 @@ function eventStatsQuery(diffs: EventStatDiff[]) {
     return row;
   });
 
-  return db.insertInto('event_stats')
+  const kysely = await DittoDB.getInstance();
+  return kysely.insertInto('event_stats')
     .values(values)
     .onConflict((oc) =>
       oc
@@ -167,14 +169,15 @@ async function getPrevEvent(event: NostrEvent): Promise<NostrEvent | undefined>
 }
 
 /** Set the following count to the total number of unique "p" tags in the follow list. */
-function updateFollowingCountQuery({ pubkey, tags }: NostrEvent) {
+async function updateFollowingCountQuery({ pubkey, tags }: NostrEvent) {
   const following_count = new Set(
     tags
       .filter(([name]) => name === 'p')
       .map(([_, value]) => value),
   ).size;
 
-  return db.insertInto('author_stats')
+  const kysely = await DittoDB.getInstance();
+  return kysely.insertInto('author_stats')
     .values({
       pubkey,
       following_count,
diff --git a/src/storages.ts b/src/storages.ts
index cbda925..f591e11 100644
--- a/src/storages.ts
+++ b/src/storages.ts
@@ -1,7 +1,8 @@
 // deno-lint-ignore-file require-await
 import { NCache } from '@nostrify/nostrify';
+
 import { Conf } from '@/config.ts';
-import { db } from '@/db.ts';
+import { DittoDB } from '@/db/DittoDB.ts';
 import { EventsDB } from '@/storages/events-db.ts';
 import { Optimizer } from '@/storages/optimizer.ts';
 import { PoolStore } from '@/storages/pool-store.ts';
@@ -24,7 +25,10 @@ export class Storages {
   /** SQLite database to store events this Ditto server cares about. */
   public static async db(): Promise<EventsDB> {
     if (!this._db) {
-      this._db = Promise.resolve(new EventsDB(db));
+      this._db = (async () => {
+        const kysely = await DittoDB.getInstance();
+        return new EventsDB(kysely);
+      })();
     }
     return this._db;
   }
diff --git a/src/storages/events-db.test.ts b/src/storages/events-db.test.ts
index dd92c1b..d935e6b 100644
--- a/src/storages/events-db.test.ts
+++ b/src/storages/events-db.test.ts
@@ -1,12 +1,14 @@
-import { db } from '@/db.ts';
-import { assertEquals, assertRejects } from '@/deps-test.ts';
+import { assertEquals, assertRejects } from '@std/assert';
+
+import { DittoDB } from '@/db/DittoDB.ts';
 
 import event0 from '~/fixtures/events/event-0.json' with { type: 'json' };
 import event1 from '~/fixtures/events/event-1.json' with { type: 'json' };
 
 import { EventsDB } from '@/storages/events-db.ts';
 
-const eventsDB = new EventsDB(db);
+const kysely = await DittoDB.getInstance();
+const eventsDB = new EventsDB(kysely);
 
 Deno.test('count filters', async () => {
   assertEquals((await eventsDB.count([{ kinds: [1] }])).count, 0);
@@ -34,7 +36,7 @@ Deno.test('query events with domain search filter', async () => {
   assertEquals(await eventsDB.query([{ search: 'domain:localhost:8000' }]), []);
   assertEquals(await eventsDB.query([{ search: '' }]), [event1]);
 
-  await db
+  await kysely
     .insertInto('pubkey_domains')
     .values({ pubkey: event1.pubkey, domain: 'localhost:8000', last_updated_at: event1.created_at })
     .execute();
diff --git a/src/storages/hydrate.ts b/src/storages/hydrate.ts
index 3109ac6..8d2d302 100644
--- a/src/storages/hydrate.ts
+++ b/src/storages/hydrate.ts
@@ -1,7 +1,7 @@
 import { NostrEvent, NStore } from '@nostrify/nostrify';
 import { matchFilter } from 'nostr-tools';
 
-import { db } from '@/db.ts';
+import { DittoDB } from '@/db/DittoDB.ts';
 import { type DittoEvent } from '@/interfaces/DittoEvent.ts';
 import { DittoTables } from '@/db/DittoTables.ts';
 import { Conf } from '@/config.ts';
@@ -239,7 +239,7 @@ function gatherReportedProfiles({ events, store, signal }: HydrateOpts): Promise
 }
 
 /** Collect author stats from the events. */
-function gatherAuthorStats(events: DittoEvent[]): Promise<DittoTables['author_stats'][]> {
+async function gatherAuthorStats(events: DittoEvent[]): Promise<DittoTables['author_stats'][]> {
   const pubkeys = new Set<string>(
     events
       .filter((event) => event.kind === 0)
@@ -250,7 +250,8 @@ function gatherAuthorStats(events: DittoEvent[]): Promise<DittoTables['author_st
     return Promise.resolve([]);
   }
 
-  return db
+  const kysely = await DittoDB.getInstance();
+  return kysely
     .selectFrom('author_stats')
     .selectAll()
     .where('pubkey', 'in', [...pubkeys])
@@ -258,7 +259,7 @@ function gatherAuthorStats(events: DittoEvent[]): Promise<DittoTables['author_st
 }
 
 /** Collect event stats from the events. */
-function gatherEventStats(events: DittoEvent[]): Promise<DittoTables['event_stats'][]> {
+async function gatherEventStats(events: DittoEvent[]): Promise<DittoTables['event_stats'][]> {
   const ids = new Set<string>(
     events
       .filter((event) => event.kind === 1)
@@ -269,7 +270,8 @@ function gatherEventStats(events: DittoEvent[]): Promise<DittoTables['event_stat
     return Promise.resolve([]);
   }
 
-  return db
+  const kysely = await DittoDB.getInstance();
+  return kysely
     .selectFrom('event_stats')
     .selectAll()
     .where('event_id', 'in', [...ids])