diff --git a/ui/src/app/api/jobs/[jobID]/delete/route.ts b/ui/src/app/api/jobs/[jobID]/delete/route.ts
index e2d3a0c..8fa2422 100644
--- a/ui/src/app/api/jobs/[jobID]/delete/route.ts
+++ b/ui/src/app/api/jobs/[jobID]/delete/route.ts
@@ -1,11 +1,9 @@
 import { NextRequest, NextResponse } from 'next/server';
-import { PrismaClient } from '@prisma/client';
+import prisma from '@/server/prisma';
 import { getTrainingFolder } from '@/server/settings';
 import path from 'path';
 import fs from 'fs';
 
-const prisma = new PrismaClient();
-
 export async function GET(request: NextRequest, { params }: { params: { jobID: string } }) {
   const { jobID } = await params;
 
diff --git a/ui/src/app/api/jobs/[jobID]/files/route.ts b/ui/src/app/api/jobs/[jobID]/files/route.ts
index c0642d7..b8fc1c8 100644
--- a/ui/src/app/api/jobs/[jobID]/files/route.ts
+++ b/ui/src/app/api/jobs/[jobID]/files/route.ts
@@ -1,11 +1,9 @@
 import { NextRequest, NextResponse } from 'next/server';
-import { PrismaClient } from '@prisma/client';
+import prisma from '@/server/prisma';
 import path from 'path';
 import fs from 'fs';
 import { getTrainingFolder } from '@/server/settings';
 
-const prisma = new PrismaClient();
-
 export async function GET(request: NextRequest, { params }: { params: { jobID: string } }) {
   const { jobID } = await params;
 
diff --git a/ui/src/app/api/jobs/[jobID]/log/route.ts b/ui/src/app/api/jobs/[jobID]/log/route.ts
index c353166..731a546 100644
--- a/ui/src/app/api/jobs/[jobID]/log/route.ts
+++ b/ui/src/app/api/jobs/[jobID]/log/route.ts
@@ -1,12 +1,10 @@
 import { NextRequest, NextResponse } from 'next/server';
-import { PrismaClient } from '@prisma/client';
+import prisma from '@/server/prisma';
 import path from 'path';
 import fs from 'fs';
 import type { FileHandle } from 'fs/promises';
 import { getTrainingFolder } from '@/server/settings';
 
-const prisma = new PrismaClient();
-
 export async function GET(request: NextRequest, { params }: { params: { jobID: string } }) {
   const { jobID } = await params;
 
diff --git a/ui/src/app/api/jobs/[jobID]/loss/route.ts b/ui/src/app/api/jobs/[jobID]/loss/route.ts
index e6437a2..89ac0df 100644
--- a/ui/src/app/api/jobs/[jobID]/loss/route.ts
+++ b/ui/src/app/api/jobs/[jobID]/loss/route.ts
@@ -1,5 +1,5 @@
 import { NextRequest, NextResponse } from 'next/server';
-import { PrismaClient } from '@prisma/client';
+import prisma from '@/server/prisma';
 import path from 'path';
 import fs from 'fs';
 import { getTrainingFolder } from '@/server/settings';
@@ -8,8 +8,6 @@ import sqlite3 from 'sqlite3';
 
 export const runtime = 'nodejs';
 
-const prisma = new PrismaClient();
-
 function openDb(filename: string) {
   const db = new sqlite3.Database(filename);
   db.configure('busyTimeout', 30_000);
diff --git a/ui/src/app/api/jobs/[jobID]/mark_stopped/route.ts b/ui/src/app/api/jobs/[jobID]/mark_stopped/route.ts
index 39cd353..2b38cc6 100644
--- a/ui/src/app/api/jobs/[jobID]/mark_stopped/route.ts
+++ b/ui/src/app/api/jobs/[jobID]/mark_stopped/route.ts
@@ -1,7 +1,5 @@
 import { NextRequest, NextResponse } from 'next/server';
-import { PrismaClient } from '@prisma/client';
-
-const prisma = new PrismaClient();
+import prisma from '@/server/prisma';
 
 export async function GET(request: NextRequest, { params }: { params: { jobID: string } }) {
   const { jobID } = await params;
diff --git a/ui/src/app/api/jobs/[jobID]/plugin/route.ts b/ui/src/app/api/jobs/[jobID]/plugin/route.ts
index cadcf00..946ea2f 100644
--- a/ui/src/app/api/jobs/[jobID]/plugin/route.ts
+++ b/ui/src/app/api/jobs/[jobID]/plugin/route.ts
@@ -1,11 +1,9 @@
 import { NextRequest, NextResponse } from 'next/server';
-import { PrismaClient } from '@prisma/client';
+import prisma from '@/server/prisma';
 import path from 'path';
 import fs from 'fs';
 import { getTrainingFolder } from '@/server/settings';
 
-const prisma = new PrismaClient();
-
 export async function GET(request: NextRequest, { params }: { params: { jobID: string } }) {
   const { jobID } = await params;
 
diff --git a/ui/src/app/api/jobs/[jobID]/sample_now/route.ts b/ui/src/app/api/jobs/[jobID]/sample_now/route.ts
index 7d785be..37ef136 100644
--- a/ui/src/app/api/jobs/[jobID]/sample_now/route.ts
+++ b/ui/src/app/api/jobs/[jobID]/sample_now/route.ts
@@ -1,7 +1,5 @@
 import { NextRequest, NextResponse } from 'next/server';
-import { PrismaClient } from '@prisma/client';
-
-const prisma = new PrismaClient();
+import prisma from '@/server/prisma';
 
 export async function GET(request: NextRequest, { params }: { params: { jobID: string } }) {
   const { jobID } = await params;
diff --git a/ui/src/app/api/jobs/[jobID]/samples/route.ts b/ui/src/app/api/jobs/[jobID]/samples/route.ts
index d5f9bd8..6a2aafe 100644
--- a/ui/src/app/api/jobs/[jobID]/samples/route.ts
+++ b/ui/src/app/api/jobs/[jobID]/samples/route.ts
@@ -1,11 +1,9 @@
 import { NextRequest, NextResponse } from 'next/server';
-import { PrismaClient } from '@prisma/client';
+import prisma from '@/server/prisma';
 import path from 'path';
 import fs from 'fs';
 import { getTrainingFolder } from '@/server/settings';
 
-const prisma = new PrismaClient();
-
 export async function GET(request: NextRequest, { params }: { params: { jobID: string } }) {
   const { jobID } = await params;
 
diff --git a/ui/src/app/api/jobs/[jobID]/save_now/route.ts b/ui/src/app/api/jobs/[jobID]/save_now/route.ts
index 0a6e54b..6addbe6 100644
--- a/ui/src/app/api/jobs/[jobID]/save_now/route.ts
+++ b/ui/src/app/api/jobs/[jobID]/save_now/route.ts
@@ -1,7 +1,5 @@
 import { NextRequest, NextResponse } from 'next/server';
-import { PrismaClient } from '@prisma/client';
-
-const prisma = new PrismaClient();
+import prisma from '@/server/prisma';
 
 export async function GET(request: NextRequest, { params }: { params: { jobID: string } }) {
   const { jobID } = await params;
diff --git a/ui/src/app/api/jobs/[jobID]/start/route.ts b/ui/src/app/api/jobs/[jobID]/start/route.ts
index 0417dcf..34cb9ce 100644
--- a/ui/src/app/api/jobs/[jobID]/start/route.ts
+++ b/ui/src/app/api/jobs/[jobID]/start/route.ts
@@ -1,7 +1,5 @@
 import { NextRequest, NextResponse } from 'next/server';
-import { PrismaClient } from '@prisma/client';
-
-const prisma = new PrismaClient();
+import prisma from '@/server/prisma';
 
 export async function GET(request: NextRequest, { params }: { params: { jobID: string } }) {
   const { jobID } = await params;
diff --git a/ui/src/app/api/jobs/[jobID]/stop/route.ts b/ui/src/app/api/jobs/[jobID]/stop/route.ts
index 8b49f53..cb14ad6 100644
--- a/ui/src/app/api/jobs/[jobID]/stop/route.ts
+++ b/ui/src/app/api/jobs/[jobID]/stop/route.ts
@@ -1,10 +1,9 @@
 import { NextRequest, NextResponse } from 'next/server';
-import { PrismaClient } from '@prisma/client';
+import prisma from '@/server/prisma';
 import { exec } from 'child_process';
 import { promisify } from 'util';
 
 const execAsync = promisify(exec);
-const prisma = new PrismaClient();
 const isWindows = process.platform === 'win32';
 
 export async function GET(request: NextRequest, { params }: { params: { jobID: string } }) {
diff --git a/ui/src/app/api/jobs/route.ts b/ui/src/app/api/jobs/route.ts
index 2077846..b953069 100644
--- a/ui/src/app/api/jobs/route.ts
+++ b/ui/src/app/api/jobs/route.ts
@@ -1,10 +1,8 @@
 import { NextResponse } from 'next/server';
-import { PrismaClient } from '@prisma/client';
+import prisma from '@/server/prisma';
 import { isMac } from '@/helpers/basic';
 import { cached } from '@/server/apiCache';
 
-const prisma = new PrismaClient();
-
 export async function GET(request: Request) {
   const { searchParams } = new URL(request.url);
   const id = searchParams.get('id');
diff --git a/ui/src/app/api/queue/[queueID]/start/route.ts b/ui/src/app/api/queue/[queueID]/start/route.ts
index d67ff4e..3bc6791 100644
--- a/ui/src/app/api/queue/[queueID]/start/route.ts
+++ b/ui/src/app/api/queue/[queueID]/start/route.ts
@@ -1,7 +1,5 @@
 import { NextRequest, NextResponse } from 'next/server';
-import { PrismaClient } from '@prisma/client';
-
-const prisma = new PrismaClient();
+import prisma from '@/server/prisma';
 
 export async function GET(request: NextRequest, { params }: { params: { queueID: string } }) {
   const { queueID } = await params;
diff --git a/ui/src/app/api/queue/[queueID]/stop/route.ts b/ui/src/app/api/queue/[queueID]/stop/route.ts
index 87e608b..03f9b37 100644
--- a/ui/src/app/api/queue/[queueID]/stop/route.ts
+++ b/ui/src/app/api/queue/[queueID]/stop/route.ts
@@ -1,7 +1,5 @@
 import { NextRequest, NextResponse } from 'next/server';
-import { PrismaClient } from '@prisma/client';
-
-const prisma = new PrismaClient();
+import prisma from '@/server/prisma';
 
 export async function GET(request: NextRequest, { params }: { params: { queueID: string } }) {
   const { queueID } = await params;
diff --git a/ui/src/app/api/queue/route.ts b/ui/src/app/api/queue/route.ts
index 08c6d4b..eb1eb86 100644
--- a/ui/src/app/api/queue/route.ts
+++ b/ui/src/app/api/queue/route.ts
@@ -1,7 +1,5 @@
 import { NextResponse } from 'next/server';
-import { PrismaClient } from '@prisma/client';
-
-const prisma = new PrismaClient();
+import prisma from '@/server/prisma';
 
 export async function GET(request: Request) {
   const { searchParams } = new URL(request.url);
diff --git a/ui/src/app/api/settings/route.ts b/ui/src/app/api/settings/route.ts
index 62528cd..24722a2 100644
--- a/ui/src/app/api/settings/route.ts
+++ b/ui/src/app/api/settings/route.ts
@@ -1,10 +1,8 @@
 import { NextResponse } from 'next/server';
-import { PrismaClient } from '@prisma/client';
+import prisma from '@/server/prisma';
 import { defaultTrainFolder, defaultDatasetsFolder } from '@/paths';
 import { flushCache } from '@/server/settings';
 
-const prisma = new PrismaClient();
-
 export async function GET() {
   try {
     const settings = await prisma.settings.findMany();
diff --git a/ui/src/server/prisma.ts b/ui/src/server/prisma.ts
new file mode 100644
index 0000000..b6b536e
--- /dev/null
+++ b/ui/src/server/prisma.ts
@@ -0,0 +1,16 @@
+import { PrismaClient } from '@prisma/client';
+
+// Single shared PrismaClient for the whole server. Route files must import
+// this instead of constructing their own client — each PrismaClient spawns
+// its own query engine + connection pool, and a pile of them contending for
+// the same sqlite file just adds lock pressure. The globalThis stash keeps
+// dev hot-reload from leaking a new client on every recompile.
+const globalForPrisma = globalThis as unknown as { prisma?: PrismaClient };
+
+const prisma = globalForPrisma.prisma ?? new PrismaClient();
+
+if (process.env.NODE_ENV !== 'production') {
+  globalForPrisma.prisma = prisma;
+}
+
+export default prisma;
diff --git a/ui/src/server/settings.ts b/ui/src/server/settings.ts
index 9c6abe6..7a0a675 100644
--- a/ui/src/server/settings.ts
+++ b/ui/src/server/settings.ts
@@ -1,10 +1,9 @@
-import { PrismaClient } from '@prisma/client';
+import prisma from '@/server/prisma';
 import { defaultDatasetsFolder, defaultDataRoot } from '@/paths';
 import { defaultTrainFolder } from '@/paths';
 import NodeCache from 'node-cache';
 
 const myCache = new NodeCache();
-const prisma = new PrismaClient();
 
 export const flushCache = () => {
   myCache.flushAll();