Model identifiers
The quickstart uses a Hugging Face style model identifier:Placement solvers
tandemn plan and tandemn deploy can show recommendations from two built-in solvers:
If the advisor is unavailable, Tandemn falls back to the roofline solver. If
KOI_SERVICE_URL is set, Tandemn can also show an optional Koi recommendation.
The LLM Advisor requires ANTHROPIC_API_KEY and the performance database. Without those, tandemn plan and tandemn deploy can still use the roofline solver.
Performance database
The LLM placement advisor uses a performance database of profiled vLLM runs. Download it into the server repository:Profiled models
For models not in the database, the advisor estimates throughput by matching model family, size, and I/O profile. Use
--gpu, --tp, and --pp when you want to override placement manually.
Routing goals
Tandemn’s routing layer is designed to reduce the amount of manual placement work users need to do. Instead of asking each user to pick a specific machine, Tandemn can evaluate the job and choose an appropriate hardware mix.What affects placement
The exact placement decision depends on deployment-specific configuration, but these are the common inputs to reason about:- Model size and runtime requirements
- Prompt file size
- Requested SLO
- Available GPUs
- Current cluster load
- AWS quota and capacity
- Spot or on-demand launch mode
- Tensor and pipeline parallelism settings
Supported hardware
The solver searches across GPU types and parallelism configurations to find a placement that fits the model in memory and meets the requested deadline.
If a model cannot be scheduled, the first thing to check is whether the model is enabled in the deployment and whether compatible resources are available.

