Beyond the Database: The N+1 API Trap

Most developers associate the N+1 problem exclusively with database ORMs like Laravel Eloquent. We’ve all been there: you forget to eager-load a relationship, and suddenly your application is firing 100 queries to fetch 100 records.

However, I recently encountered a "classic" N+1 issue in a completely different environment: Third-party API integrations.

The Symptom: Slowness and Isolated Rooms

While working on a platform using Twilio for video and voice consultations, we started seeing two critical issues:

• Growing Latency: As the platform scaled, the time it took to join a call increased significantly.
• The "Ghost Room" Bug: Two users would try to join the same consultation but end up in separate, isolated rooms where they couldn't see or hear each other.

Interestingly, if a user refreshed their page, they could often successfully join the other party, but the initial experience was broken.

The Culprit: "Fetch All and Filter"

The issue wasn't in the database; it was in how we were interacting with the Twilio API. To find a specific conversation, the code was fetching every single active conversation and looping through them to find a match.

// TwilioService.php
public function getRoom(string $name) {
    // This fetches ALL conversations from the API
    $conversations = $this->client->conversations->v1->conversations->read();

    foreach ($conversations as $conversation) {
        // High-latency loop searching for a match
        if ($conversation->friendlyName === $name) {
            return $conversation;
        }
    }
}

Why This Fails at Scale

When the application was new, this code was fast because there were only a few active calls. But as the number of users grew, two things happened:

1. Variable "N": The read() method had to fetch an ever-increasing list of conversations from Twilio's servers.
2. API Latency: Unlike a local database query, every "page" of results from a third-party API requires a network round-trip.
3. Race Conditions: Because finding a room took so long, two users joining at the same time might not find an existing room fast enough, leading the system to create duplicates.

Key Takeaway: An N+1 problem exists whenever the time it takes to find a resource is dependent on the total number of resources (N) rather than a direct identifier.

The Fix: Direct Fetching

The solution is to move from Fetch All → Filter to Direct Access.

Instead of listing all conversations, you should store the unique SID of the Twilio conversation in your local database. This allows you to fetch the exact resource you need in a single API call:

// The Optimized Way
$conversation = $this->client->conversations->v1->conversations($storedSid)->fetch();

By using a direct identifier, the "join" time remains constant (O(1) relative to your list size), regardless of whether you have 10 or 10,000 active calls.