Anatomy of a production LLM service: the map for the whole course
One diagram and one checklist that place every later lesson: the path of a request from client to GPU and back, the supporting systems around it (scaling, observability, rollouts, cost), and what 'ready for production' means.
Here is the whole system on one page. Every lesson in the course zooms into one box.
#A request, end to end
- 1Clientapp or user
- 2Gatewayauth, rate limits, routing, failover
- 3Routerpicks a replica, prefix-aware where it helps
- 4Model serverbatching, KV cache, generation on the GPU
- 5Stream backtokens flow to the client
- 6Logs, metrics and tracesrecorded on the way
#The systems around it
- 1Cost and tenancyquotas, billing, FinOps
- 2DeliveryCI for models, canaries, rollbacks
- 3Observabilitylogs, metrics, traces, SLOs, alerts
- 4Scalingautoscaling, cold starts, batch pools, regions
- 5PlatformKubernetes, GPU scheduling, images, weights
- 6Servingengine, batching, cache, API
Read it bottom up: you serve a model, run it on a platform, scale it, watch it, change it safely and pay for it.
#Where each area fits
| Box | The question | Course area |
|---|---|---|
| Model server | How fast and how many users per GPU? | Inference Engineering and Architecture |
| Platform | How do I run and schedule GPUs? | Kubernetes |
| Scaling | How do I add and remove capacity? | Scaling |
| Observability | Is it healthy, and for whom? | Observability |
| Delivery | How do I change it without breaking it? | Operations and Delivery |
| Cost | What does a token cost? | Architecture and Delivery |
#What makes LLM serving different
| Property | Consequence |
|---|---|
| Requests last seconds and stream | Timeouts, proxies and load balancing need care |
| GPUs are scarce and slow to start | Autoscaling must plan for cold starts (loading tens of gigabytes) |
| Work per request varies enormously | Queueing and capacity planning use token counts, not request counts |
| State lives in the KV cache | Routing can raise hit rates; memory is a hard limit |
| Quality can regress silently | Evaluation belongs in CI and in production monitoring |
| Cost is per token and per GPU-hour | Utilisation is the main cost lever |
#A production-readiness checklist
Before launch, can you say yes to each of these?
- Workload known: peak requests per second, prompt and output lengths, latency targets.
- Capacity planned: GPUs sized with headroom; cost per million tokens known.
- Health checks and graceful shutdown work; replicas are removed from rotation before they stop.
- Autoscaling is tested, including cold starts.
- Observability: structured logs, GPU and engine metrics, traces for slow requests.
- SLOs and alerts exist, and they page on user pain, not on noise.
- Rollouts use canaries; rollback is one command and has been tried.
- Limits: per-tenant quotas, request size caps, timeouts, max tokens.
- Security basics: authentication, input limits, secrets handling (security course).
- Runbooks: what to do when the GPU fails, the queue backs up or latency spikes.
- Cost tracking by tenant or feature.
- A capstone-style drill: you have run a load test and a failure test, and know what happened.
#How to use this map
Whenever a lesson feels abstract, find its box and ask what breaks without it. The course ends with a capstone that walks this checklist for a service of your own design.
#Exercise
A GPU node dies while 40 requests are streaming. Name three parts of the map that determine how bad this is for users, and one question to ask about each.
Answer: the gateway or router (does it retry or fail over, and are requests safe to retry?), scaling (how long until replacement capacity is ready, given the cold start?), and observability (how quickly does an alert fire, and do traces show which requests were hit?). The client code matters too: its timeouts and retry behaviour decide what users see.
Next: From laptop to production.
Quick quiz
+10 XP per correct answer, +25 XP for a perfect score
1. What does the gateway usually handle?
2. Why are queue depth and KV-cache usage useful autoscaling signals?
3. Which is part of production readiness?
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