Pathfinder — Smart DSP Routing

Every bid request costs time and money to process. Sending it to demand sources (DSPs) that won’t bid — wrong geography, wrong format, budget exhausted, endpoint down — wastes 40–60% of your auction budget. Pathfinder eliminates that waste before the auction starts.

What Pathfinder does

Before running an auction, Pathfinder evaluates each demand source in the platform and decides which ones receive the bid request for this specific impression. Demand sources that can’t or won’t bid are excluded.

Result: Fewer bid requests sent, faster auctions, higher fill rates, and less unnecessary load on demand source infrastructure.

How it works

Pathfinder applies five filters in sequence:

Incoming bid request
        ↓
1. Pool membership check
        ↓
2. Geographic filter
        ↓
3. Format compatibility check
        ↓
4. Circuit breaker state
        ↓
5. Guide QPS budget check
        ↓
Eligible DSPs → Auction

1. Pool membership

Every supply source belongs to a pool. Every demand source subscribes to one or more pools. If a demand source hasn’t subscribed to the supply source’s pool, they don’t receive the request.

This is the primary targeting mechanism — demand sources opt into inventory categories they want, and Pathfinder enforces it automatically.

2. Geographic filter

Pathfinder checks whether the demand source has configured geographic targeting. If the demand source only bids on UAE and Saudi traffic, requests from UK supply sources are filtered out before the auction.

Demand sources configure geo targeting under Demand → Settings → Geographic Targeting.

3. Format compatibility

If the impression is a CTV video (imp.video) and the demand source only supports banner (imp.banner), the request is filtered. Pathfinder reads the demand source’s declared format capabilities and matches them against the impression format.

4. Circuit breaker state

If the demand source’s circuit breaker is open (too many recent timeouts or errors), Pathfinder skips it entirely until the breaker resets. → Circuit breaker details

5. Guide QPS budget

If Guide has calculated that the demand source has reached its daily budget, it sets the demand source’s QPS allowance to zero. Pathfinder respects this limit and excludes the demand source. → Guide details

Eligibility cache

Recalculating eligibility for every auction would add latency. Pathfinder caches demand source eligibility per supply source in Redis, refreshed every 30 seconds.

Cache key: pathfinder:eligible:{publisher_id}
TTL: 30 seconds
Value: sorted list of eligible DSP IDs

When a demand source’s config changes (new geo targeting, pool change, circuit breaker state flip), the cache is invalidated and rebuilt within 30 seconds.

There is up to a 30-second delay between a demand source config change and Pathfinder reflecting it. For circuit breaker resets, recovery happens within the next cache refresh cycle.

Performance impact

Metric	Without Pathfinder	With Pathfinder
Bid requests sent per auction	All registered demand sources	Only eligible demand sources
Wasted requests	40–60%	~0%
Auction latency contribution	Higher (waiting for non-bidders)	Lower
Demand source infrastructure load	High	Reduced proportionally

In a platform with 20 demand sources where 8 are eligible for a given auction, Pathfinder reduces bid requests by 60%.

Monitoring

Pathfinder filtering is visible in the dashboard under Demand → your demand source → Pathfinder Stats:

Requests eligible (passed all filters)
Requests filtered by pool
Requests filtered by geo
Requests filtered by format
Requests filtered by circuit breaker
Requests filtered by budget

Use this to diagnose why a demand source is receiving fewer requests than expected.

Revenue Share & Reporting Defender — IVT Detection