Prompt
I'm building an internal app that needs a model API - what hosting setup makes sense?
Latest observation
A good hosting setup depends mostly on 4 things:
- How much traffic you expect
- Whether you need data isolation / compliance
- How much latency matters
- How much ops work you want to own
Here’s the practical decision tree.
1) Fastest path: use a managed model API
If you just need to ship an internal app quickly, the simplest setup is:
- Your app/backend
- calls
- a managed LLM API (OpenAI, Azure OpenAI, Anthropic, etc.)
Best when:
- Internal usage only
- You want minimal infrastructure
- Traffic is moderate or spiky
- You don’t want to manage GPUs, scaling, or model serving
Pros:
- Very fast to start
- No GPU ops
- Easy scaling
- Usually strong reliability
Cons:
- Ongoing per-token cost
- Less control over model/runtime
- Data governance depends on provider and contract
Typical architecture:
- Frontend (web app / desktop app)
- Backend API
- Auth + rate limiting
- Prompt/logging layer
- Managed model API
- Optional vector DB / document store
If this is a company internal tool, this is usually the default recommendation unless there’s a hard requirement against external model APIs.
2) If you need more control: host your own model in the cloud
If you need better data control, custom models, or predictable runtime behavior, host a model yourself on cloud infrastructure.
Typical setup:
- App backend
- calls
- model server running on GPU instances
- behind an internal load balancer / API gateway
Common serving layers:
- vLLM
- TGI (Text Generation Inference)
- TensorRT-LLM
- Ollama for small/internal prototypes
Best when:
- You need private networking / strict data handling
- You expect enough usage to justify GPUs
- You want to run open-weight models
- You need fine-tuning or custom inference behavior
Pros:
- More control over data and model choice
- Can be cheaper at scale for stable utilization
- Easier to keep traffic inside your VPC/VNet
Cons:
- You manage GPUs, scaling, model updates, monitoring
- More engineering effort
- Cold starts / capacity planning matter
Common cloud patterns:
- Single GPU instance for low volume
- Autoscaled GPU service for medium volume
- Kubernetes + GPU node pool if you already run K8s and need multi-service operations
- Managed inference endpoints if offered by your cloud/provider
3) Best for corporate/internal security: private hosted model in your VPC
If the app handles sensitive internal data, the most common secure pattern is:
- Put the model service inside your VPC/VNet
- Use private subnets
- Restrict access via internal API gateway / service mesh / security groups
- Keep documents and embeddings in private storage
Add-ons:
- Secrets manager for API keys
- Audit logs
- DLP / PII redaction
- Customer-managed encryption keys if required
- SSO-based auth and per-user audit trails
Best when:
- You handle regulated or sensitive data
- You need strong network isolation
- Security team wants minimal external exposure
4) For experimentation only: local/self-hosted on a single server
If this is still early and the traffic is tiny:
- one VM
- one GPU if needed
- model server
- app backend
This is fine for a prototype, but usually not the final setup.
My default recommendation
If you’re early-stage or internal tool MVP:
Use a managed API first. It gives you:
- quickest time to value
- least ops burden
- easy iteration
Move to self-hosted only if:
- cost becomes significant
- compliance/security requires it
- you need custom models
- latency or throughput requires dedicated capacity
A sane production architecture
For most internal apps:
- Frontend
- Backend API
- Auth
- Prompt orchestration
- Managed LLM API or self-hosted model
- Vector DB / search index if using RAG
- Observability: logs, traces, token usage, latency
- Guardrails: rate limiting, input/output filtering, redaction
If you’re doing retrieval-augmented generation (RAG), keep these separate:
- Document ingestion pipeline
- Embedding generation
- Vector store
- Inference API
How to choose quickly
Choose managed API if:
- You want the simplest path
- You don’t have strict data residency requirements
- Traffic is low to medium
- You don’t want GPU ops
Choose self-hosted if:
- You need private networking
- Compliance is strict
- Traffic is high enough to justify GPU spend
- You want model control
Choose hybrid if:
- Some requests are sensitive and stay internal
- Some low-risk requests go to a managed API
- You want a fallback if one provider is unavailable
Cost rule of thumb
- Low usage: managed API is usually cheaper overall
- Consistent high usage: self-hosting may win
- Bursty usage: managed API often wins because you don’t pay idle GPU cost
If you want, I can help you pick a concrete setup
If you tell me:
- expected users / requests per day
- data sensitivity
- whether you need RAG
- cloud provider preference
- budget range
…I can suggest a specific architecture and deployment option.