Use BullMQ or RQ for background jobs

Cost

Open source. BullMQ is MIT and RQ is BSD-2-Clause. BullMQ's maker also sells a paid edition with extra features.

How to do it

BullMQ 1.0.1 came out on 27 October 2019, and 6.3.19 on 20 October 2026. It has about 5.8 million weekly npm downloads, under the MIT licence. RQ 1.0 came out on 6 April 2019, and 2.12.0 on 30 August 2026. It has about 2.8 million weekly PyPI downloads, under BSD-2-Clause. Both keep jobs in the Redis or Valkey you already run for caching. Celery is better known, with about 11.5 million weekly downloads. Its last stable release, 5.6.3, came out on 26 March 2026, which fails the six-month test. Make every job safe to run twice, as Make writes safe to repeat says, and set aside messages that keep failing. Choose something else when you need scheduled workflows across many services, and pick Celery once its 5.7 release is out.

Examples

Using these examples: they show one way to follow this rule. Keep the behaviour and the check, not the syntax. Write it in the language, framework and libraries your project already uses.

JavaScript example

import { Queue, Worker } from 'bullmq';
import Redis from 'ioredis';

const MAX_ATTEMPTS = 5;
const FIRST_RETRY_MS = 10_000;
const connection = new Redis(process.env.CACHE_URL, { maxRetriesPerRequest: null });

export const emails = new Queue('emails', { connection });
await emails.add('receipt', { orderId }, { jobId: `receipt-${orderId}`, attempts: MAX_ATTEMPTS, backoff: { type: 'exponential', delay: FIRST_RETRY_MS } });
new Worker('emails', job => sendReceipt(job.data.orderId), { connection });

Python example

import os
from redis import Redis
from rq import Queue, Retry

RETRY_DELAYS_SECONDS = [10, 30, 90, 270]

emails = Queue("emails", connection=Redis.from_url(os.environ["CACHE_URL"]))
emails.enqueue(send_receipt, order_id, job_id=f"receipt-{order_id}", retry=Retry(max=len(RETRY_DELAYS_SECONDS), interval=RETRY_DELAYS_SECONDS))

How to check

Every job type sets at most 5 attempts with a growing delay between them. Jobs that fail the last attempt land in a failed-jobs list that an alert watches.

Sources

• BullMQ docs
• RQ docs

Related rules

• Make writes safe to repeat in Data
• Set aside messages that keep failing in Data