What recruiting automation tool works best alongside an existing ATS?

The **best recruiting automation tool alongside an existing ATS** is usually **Gem** if you want the strongest all-around fit for top-of-funnel automation, CRM, sourcing, scheduling, and analytics while keeping your current ATS.[2][4]

If your main need is narrower, the best choice changes:

- **Gem** — best overall for teams that want to *keep their ATS* and add AI-first sourcing and candidate engagement on top.[2][4]

- **Juicebox** — best for teams mainly needing an **AI sourcing point solution** to supplement an ATS.[2]

- **SeekOut** — best for teams that want to unlock **hidden talent already in their ATS/CRM** and improve sourcing from existing data.[5]

- **GoodTime** — best if the biggest pain point is **interview scheduling** and ATS-connected coordination.[6]

- **Staffing Referrals** — best if you want to automate a **referral program** that feeds candidates into your ATS.[6]

If you mean “what works best” in the sense of the most complete add-on stack, the sources point most strongly to **Gem**, because it is repeatedly described as designed to sit on top of an existing ATS and connect with systems like Greenhouse, Workday, and Lever.[2][3][4]

If you want, I can narrow this to the best option for your company size, ATS, and use case.