# Thread: Sequential Fallback Is Broken

1/
Every LLM gateway works the same way:

Try A. Wait. Fail. Try B. Wait. Fail. Try C.

That's sequential fallback. It's everywhere. It's also mathematically stupid.

2/
Let's do the math.

Service A: 5 second timeout? Wait 5s.
Service B: 5 seconds? Wait another 5s.
Service C: 5 seconds? Wait another 5s.

Worst-case sequential: 15 seconds for a single request.

3/
Now parallel:

A, B, C fire at the same time.

First one back wins. Worst case: 5 seconds.

15s sequential vs 5s parallel. 3x faster. Same outcome.

4/
Here's where it gets better.

3 parallel requests cost less than 2 sequential requests.

Why? Because you get the answer from the fastest provider. The other two cancel. You pay for the winner.

5/
Sequential means you pay for every failure along the way.

Parallel means you pay for one success.

That's not optimization. That's basic arithmetic.

6/
We built A3M Router around this one idea:

Fire everything. Take the first answer. Never wait for a failure.

The math speaks for itself.

GitHub: https://github.com/Das-rebel/adaptive-memory-multi-model-router
