ATS API Integration: What They Don't Tell You

Connecting to ATS APIs seems straightforward at first. But once you start building, you discover a minefield of hidden challenges. Here's what nobody talks about when they say "just use the API."

The API Exists — But Getting Access Is Hard

Here's the first thing nobody mentions: the ATS APIs aren't public in the way you think.

Greenhouse and Ashby: Per-Company Keys

Greenhouse and Ashby require an API key from each company you want to track. That means:

• You need a relationship with each company
• They need to generate and share an API key with you
• They can revoke access at any time
• Many companies simply say no

Lever: Better, But Not Perfect

Lever is the easiest — no authentication required. But you still need to know which companies use Lever, and their job data changes frequently.

The Data Format Problem

Even when you get the data, here's what happens:

• Greenhouse returns jobs with rich metadata: departments, offices, hiring team, application links
• Lever returns jobs with teams and locations, but different field names
• Ashby returns jobs with its own unique structure

Now you need to build a normalization layer to make these look the same. One day your database schema changes. Another day an ATS updates their field names. This is maintenance that never ends.

Rate Limits Will Kill Your Pipeline

Each ATS has rate limits, and they're stricter than you think:

• Greenhouse: ~150 requests per minute (per API key)
• Lever: ~600 requests per minute (but they can change this)
• Ashby: No strict limit published, but they can throttle you

When you're tracking hundreds of companies, you need queuing, retry logic, and exponential backoff. Build that wrong and you'll get banned from the very APIs you're trying to use.

Change Detection Is Harder Than It Looks

You want to know when a company posts a new job. Simple, right? Wrong.

• Jobs get removed and re-added (so your "new job" alert is wrong)
• Jobs get edited (did it change significantly or just a typo fix?)
• The ATS updates their data format (your parser breaks)
• You need to remember what you saw last time (database state management)

We spent months perfecting our change detection algorithm. It's harder than it sounds.

Maintenance Is the Real Cost

Here's what nobody calculates upfront:

That's engineering time that could go toward your core product. Is tracking job postings really your competitive advantage?

Frequently Asked Questions

How many companies use Greenhouse, Lever, or Ashby?

Combined, these three ATS platforms power over 4,000 companies. Greenhouse has the largest share (2,000+), followed by Lever (1,500+) and Ashby (500+ and growing fast).

Can't I just use a general job API instead?

General job APIs (Indeed, Glassdoor, etc.) aggregate from multiple sources, which means delayed data and duplicates. For real-time, accurate hiring signals, you need direct ATS API access.

How long does it take to build ATS integration?

Connecting to one ATS takes a few days. But maintaining it long-term — handling rate limits, parsing different formats, managing API keys, handling deprecations — takes ongoing engineering time that adds up quickly.

Is there an easier way to get ATS job data?

Yes. HirePulse handles all ATS integrations for you — Greenhouse, Lever, and Ashby. We manage the API keys, normalize the data, and detect changes so you can focus on your core business.

What's the Alternative?

Instead of building and maintaining ATS integrations yourself, use HirePulse:

• No API keys needed — We handle the relationships
• Normalized data — Same format regardless of ATS
• Change detection built-in — We tell you what's new
• 4,000+ companies — More than you could track yourself
• Maintenance-free — We handle all the API changes

What's Next?

Ready to skip the complexity?

• Join the waitlist for early access
• Learn how to track jobs with n8n (no code)
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