𝗪𝗲 𝗢𝗯𝘀𝗲𝘀𝘀𝗲𝗱 𝗢𝘃𝗲𝗿 𝗚𝗮𝘁𝗲𝘄𝗮𝘆 𝗟𝗮𝘁𝗲𝗻𝗰𝘆 𝗙𝗼𝗿 𝗔 𝗠𝗼𝗻𝘁𝗵

𝗪𝗲 𝗢𝗯𝘀𝗲𝘀𝘀𝗲𝗱 𝗢𝘃𝗲𝗿 𝗚𝗮𝘁𝗲𝘄𝗮𝘆 𝗟𝗮𝘁𝗲𝗻𝗰𝘆 𝗙𝗼𝗿 𝗔 𝗠𝗼𝗻𝘁𝗵

I spent a month measuring LLM gateway overhead. I tracked proxy latency down to the microsecond. I ran load tests at 500, 1000, and 5000 requests per second.

Then a teammate asked: "What percentage of total request time is the gateway?"

I ran the query. The answer was 0.3%.

Here is what LLM API calls cost in latency right now:

• GPT-4o: 850ms TTFT | 2-8s Total • Claude Sonnet 4: 900ms TTFT | 3-15s Total • Claude Fable 5: 147s TTFT | 155s Total • GPT-4.1: 1,100ms TTFT | 3-12s Total • Gemini 2.5 Flash: 500ms TTFT | 1-5s Total

Now look at what gateways add:

• Direct API call: 0ms • Python proxy: 8-40ms • Go/Rust proxy: 1-11ms

The debate is whether you add 8ms or 1ms to a call that takes 3,000ms to 155,000ms. This is like arguing about a faster USB cable for a file downloading from a satellite.

Some benchmarks claim "50x faster latency." These tests often run on tiny machines with limited resources. In production, you scale horizontally. When you use multiple instances, latency drops.

The actual LLM call takes 50x to 1000x longer than the gateway. Your latency comes from the model, not the proxy.

Here is what actually moved the needle for us:

• Model Choice: Switching from GPT-4o to Gemini 2.5 Flash for simple tasks cut latency by 60%.
• Latency-Based Routing: Routing requests to the fastest available model cut our P99 latency by 40%.
• Caching: This cut redundant calls by 30% in our workflows.
• Prompt Length: Trimming system prompts from 2000 tokens to 800 tokens made responses 35% faster.
• Failover: Automatic switching to other providers keeps your service running during outages.

If you choose an LLM gateway, focus on these things instead:

• Provider coverage: Does it support the models you need?
• Routing and failover: Does it handle outages?
• Cost tracking: Can you see which users burn tokens?
• Ecosystem: Is there a community to help when things break?
• Extensibility: Can you add custom logic easily?

Gateway overhead in microseconds is a marketing headline. It is not a production problem. I would rather have a gateway that adds 40ms but tracks my costs than a gateway that adds 1ms but leaves me blind.

What is your biggest LLM infrastructure pain point?

ਵਿਕਲਪਿਕ ਸਿੱਖਣ ਕਮਿਊਨਿਟੀ: https://t.me/GyaanSetuAi