This episode's question

Why does quality still fluctuate even after switching to a better LLM?
Because many bottlenecks are outside the model. OS scheduling and network latency still shape user-perceived performance.

The historical link to today's stack

In early computing, raw compute was the main constraint. As operating systems matured, the core challenge became reliable task orchestration. As networks expanded, placement and transport choices became central to performance.

The same logic applies now. Even with larger model parameters, production quality is governed by process scheduling, memory pressure, and network paths.

Three bottlenecks teams feel first

Memory pressure from larger context windows
Longer inputs increase memory load and often raise end-to-end latency.
Higher network cost in multimodal requests
Upload, transfer, and conversion stages add delay compared with text-only flows.
Serial chain delay in AI agent workflows
When multiple steps run in sequence, each delay compounds total response time.

Practical rules you can apply now

Split requests by workload type into lightweight vs heavy paths.
Measure segment-level latency and optimize the slowest path first.
Define recovery routes in advance to prevent failure propagation.

Core execution summary

Item	Practical rule
System diagnosis	Separate model quality issues from system bottlenecks
Latency control	Track P95 by API stage as a default operations metric
Memory management	Use summarize/split strategies for long-context workloads
Scale policy	Predefine autoscaling rules for traffic spike zones
Success signal	Better response stability and lower error rates under same load

FAQ

Q1. Won't model upgrades solve performance problems by themselves?

They can help, but improvement remains limited if infra bottlenecks are unresolved.

Q2. Isn't network latency mostly a cloud provider issue?

Provider infrastructure matters, but routing and request strategy are still team-controlled levers.

Q3. What should readers focus on in this series?

Focus less on historical events themselves and more on what decision rules those events left us.

infrastructure Posts

Road to AI 03: Why Operating Systems and Networks Still Decide AI Service Quality