Model Ecosystem

Every model.
Right task.
Right cost.

A practitioner's guide to deploying 7+ LLM providers in production โ€” from proprietary APIs to fine-tuned open-source models running in air-gapped environments.

Providers7+ Active
PrimaryAnthropic Claude
Open SourceLlama ยท Mistral ยท Qwen
Fine-tuned Models5+ Domain
Routing StrategyTask + Cost + SLA
Private ServingvLLM ยท Ollama ยท TGI
01

LLM Provider Deep-Dives

Hands-on production experience across every major provider โ€” strengths, weaknesses, and the exact use cases each excels at.

Anthropic Claude
Proprietary API
โœณ๏ธ

Primary model for agentic workloads, complex reasoning, and enterprise deployments. Deep expertise in tool use, MCP integration, constitutional AI patterns, and multi-turn orchestration.

claude-opus-4Complex reasoning ยท Orchestration
claude-sonnet-4.6Balanced ยท Production default
claude-haiku-4.5Fast ยท High-volume tasks
Primary agentic & enterprise reasoning
OpenAI GPT-4o / o3
Proprietary API
โฌ›

Multimodal reasoning, function calling, Assistants API, and structured outputs. Used in multi-LLM routing architectures for vision tasks and code-heavy pipelines via the o-series reasoning models.

gpt-4oMultimodal ยท Vision ยท Function calls
o3-miniCode reasoning ยท Math
text-embedding-3-largeEmbeddings ยท RAG
Multimodal ยท reasoning chains
Google Gemini 2.0
Cloud-managed
๐ŸŒ

Gemini Flash and Pro via Vertex AI. Long-context processing up to 2M tokens, code execution, grounding with Google Search. Preferred for GCP-native workloads with tight BigQuery integration.

gemini-2.0-proLong-context ยท Code execution
gemini-2.0-flashFast ยท GCP-native tasks
text-embedding-004Vertex embeddings
Long-context ยท GCP-native workloads
Meta Llama 3.x / 4
Open Source
๐Ÿฆ™

Llama 3.1 405B, 70B, 8B. Fine-tuned with LoRA/QLoRA on proprietary datasets via HuggingFace PEFT. vLLM serving on OpenShift AI for regulated environments. Llama 4 Scout for multimodal on-prem.

llama-3.1-405bLargest OSS ยท Near-GPT4 quality
llama-3.1-70bFine-tuned domain models
llama-3.1-8bEdge ยท Low-latency serving
Self-hosted ยท fine-tuning ยท cost control
Mistral / Mixtral
Open Source
๐ŸŒช๏ธ

Mistral 7B, Mixtral 8x7B MoE. Exceptional performance-per-dollar. Used for high-throughput classification and extraction tasks. Mistral Large for enterprise via La Plateforme API.

mixtral-8x7bMoE ยท High-throughput batch
mistral-7bClassification ยท Extraction
mistral-largeEnterprise API
High-throughput ยท batch inference
AWS Bedrock Models
Cloud-managed
โ˜๏ธ

Titan, Nova, and third-party models (Claude, Llama, Mistral) via Bedrock. Guardrails, Knowledge Bases, and Agents APIs for enterprise-grade safety and retrieval. IAM-native auth.

claude-3-sonnet (Bedrock)Cross-region inference
amazon-nova-proAWS-native multimodal
titan-embeddings-v2Knowledge Bases RAG
AWS-native enterprise deployments
02

Provider Comparison Matrix

Provider Tool Use Long Context Fine-tuning On-prem Multimodal Cost tier Best for
Anthropic Claudeโœ“โœ“โœ“โœ“โ€”โ€”โœ“MediumAgentic, reasoning, MCP
OpenAI GPT-4oโœ“โœ“โœ“Partialโ€”โœ“โœ“HighVision, code, structured output
Gemini 2.0โœ“โœ“โœ“Vertexโ€”โœ“โœ“MediumLong context, GCP workloads
Llama 3.xPartialโœ“โœ“โœ“โœ“โœ“Llama 4LowFine-tuning, air-gap, cost
Mistral / MixtralPartialโœ“โœ“โœ“โœ“โœ“โ€”LowBatch, classification, MoE
AWS Bedrockโœ“โœ“โœ“Novaโ€”โœ“MediumAWS-native, guardrails, RAG
03

Multi-LLM Routing Logic

Every request is routed to the optimal model based on four dimensions: task type, latency SLA, cost ceiling, and data residency requirements.

Task: Complex Reasoning
Route โ†’ Claude Opus
Multi-step planning, agentic loops, MCP tool orchestration, legal/compliance analysis, code architecture reviews.
claude-opus-4 ยท $15/Mtok input
Task: Production Default
Route โ†’ Claude Sonnet
The balanced workhorse โ€” high quality, reasonable cost. Default for most enterprise tasks, customer-facing agentic features, summarisation.
claude-sonnet-4.6 ยท $3/Mtok input
Task: High Volume / Fast
Route โ†’ Claude Haiku / Mistral
Sub-100ms latency tasks, classification, entity extraction, intent detection, high-frequency webhook processing.
haiku-4.5 or mistral-7b ยท <$0.50/Mtok
Task: Vision / Multimodal
Route โ†’ GPT-4o / Gemini
Image analysis, document OCR, chart interpretation, video understanding. Claude for multimodal when tool-use is also required.
gpt-4o or gemini-2.0-pro
Task: Air-gap / Regulated
Route โ†’ Llama / Mistral (vLLM)
Data residency requirements, air-gapped networks, HIPAA/GDPR workloads where no data can leave the private cloud.
llama-3.1-70b ยท self-hosted
Task: GCP-native Analytics
Route โ†’ Gemini 2.0 Flash
BigQuery data analysis, long-context document processing, Google Search grounding, Workspace integrations.
gemini-2.0-flash ยท Vertex AI
04

Fine-tuning & Domain Adaptation

When base models aren't enough โ€” domain-specific fine-tuning with LoRA, QLoRA, and PEFT on HuggingFace.

LoRA / QLoRA Fine-tuning
Parameter-efficient fine-tuning using Low-Rank Adaptation. Train on proprietary corpora with 4-bit quantisation โ€” full 70B model quality at a fraction of GPU cost. Deployed via HuggingFace PEFT + vLLM.
LoRAQLoRAPEFT4-bit quantvLLMLlama 3.1
Domain Corpus Training
Curated domain-specific datasets from enterprise knowledge bases, clinical notes, financial filings, and proprietary documentation. Data pipeline: extraction โ†’ cleaning โ†’ deduplication โ†’ instruction tuning format.
Data pipelineInstruction tuningDPOSFTMLflow
Embedding Model Fine-tuning
Domain-adapted embedding models for retrieval โ€” fine-tuned on enterprise Q&A pairs for dramatically improved RAG recall. HuggingFace sentence-transformers with contrastive learning on domain triplets.
sentence-transformersContrastive learningMTEB evalpgvector
MLOps for Fine-tuned Models
Complete lifecycle: experiment tracking, model registry, drift detection, A/B deployment, automated retraining triggers. No fine-tuned model ships without passing eval benchmarks on held-out domain data.
MLflowModel registryDrift detectionA/B deploymentCI/CD