Technical / stack

Stack. Inference, vectors, eval, agents.

Four tables. The serving frameworks that turn weights into tokens, the vector databases that hold your embeddings, the eval and observability tools that catch regressions, and the agent frameworks you may or may not need.

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TABLE // INFERENCE CHANGES QUARTERLY

Inference Frameworks

Servers that turn weights + GPUs into tokens. Pick by workload shape, not popularity.

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Name License PagedAttention Continuous batching Structured output Quantization Best fit
vLLM Apache 2.0 yes yes yes AWQ, GPTQ, FP8, INT4, INT8 High-throughput multi-tenant serving. The default choice if you have no other constraint.
TGI (HuggingFace Text Generation Inference) Apache 2.0 yes yes limited AWQ, GPTQ, EETQ, FP8 Teams already deep in the HuggingFace ecosystem. Solid OpenAI-compatible API.
SGLang Apache 2.0 yes yes yes AWQ, GPTQ, FP8, INT4 Workloads with heavy prefix reuse (agents, RAG, long system prompts). RadixAttention helps.
Ollama MIT no no yes GGUF (Q2-Q8) Local dev, laptops, single-user. Not a production server. Built on llama.cpp.
LMDeploy Apache 2.0 yes yes limited AWQ, GPTQ, W4A16, W8A8 TurboMind backend can edge vLLM on throughput for some models. Less community than vLLM.
llama.cpp MIT no yes yes GGUF (Q2-Q8, mixed) CPU and Apple Silicon inference. Heavy quantization. Edge devices. Not for multi-GPU serving.
NVIDIA TensorRT-LLM Apache 2.0 yes yes limited FP8, INT4 AWQ, INT8 SmoothQuant Last-mile latency on NVIDIA hardware. Compile step is real. Worth it only if you've tuned vLLM and still need more.
TABLE // VECTOR DBs CHANGES QUARTERLY

Vector Databases

Storage for embeddings + fast nearest-neighbor search. Pick by deployment shape and existing stack.

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Name Deployment License Metadata filter Hybrid search Authorization evidence Best fit
pgvector Postgres extension PostgreSQL License strong (full SQL) partial Not established here; verify the exact managed offering or agency system boundary. You already run Postgres and your vector workload fits in one server. One database to back up, one to monitor.
Chroma Self-host or managed Apache 2.0 medium no Not established here; verify the exact managed offering or agency system boundary. Prototypes and small RAG apps. Easy to start. Not where you want to be at scale.
Pinecone Managed only Proprietary strong yes Not established here; verify the exact managed offering or agency system boundary. You want zero ops and will pay for it. Serverless tier scales to zero. No self-host option.
Weaviate Self-host or managed BSD-3-Clause strong yes Not established here; verify the exact managed offering or agency system boundary. Hybrid search out of the box. Modules for embedding, generation, reranking. Heavier to operate than Qdrant.
Milvus Self-host or managed (Zilliz) Apache 2.0 strong yes Not established here; verify the exact managed offering or agency system boundary. Billion-vector scale. Distributed by design. Operationally heavy. Don't pick it unless you need the scale.
Qdrant Self-host or managed Apache 2.0 strong yes Not established here; verify the exact managed offering or agency system boundary. Rust-based, fast, good filter ergonomics. Strong default for self-host when pgvector isn't enough.
LanceDB Embedded or managed Apache 2.0 medium partial Not established here; verify the exact managed offering or agency system boundary. Embedded (no server) vector DB. Good for desktop apps, notebooks, and multimodal data. Newer, with fewer war stories.
TABLE // EVAL + OBS CHANGES QUARTERLY

Eval and Observability Tools

Two adjacent categories. Eval gauges quality before you ship. Observability watches what happens after.

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Name Category License Self-host OpenTelemetry Best fit
promptfoo eval MIT yes no YAML-driven eval suites in CI. Local-first. Cheap and fast to set up. Good first eval tool.
Langfuse both MIT (core) + commercial yes yes Self-hosted observability with eval features attached. Open core. Strong choice when you can't ship traces to a vendor.
DeepEval eval Apache 2.0 yes no Pytest-style eval framework with built-in metrics (faithfulness, hallucination, relevance). For Python teams.
Phoenix (Arize) both Elastic License 2.0 yes yes OpenTelemetry-native tracing and evals. Self-host or use Arize's commercial AX product. Good if you want OTel everywhere.
Helicone observability Apache 2.0 (core) + commercial SaaS yes partial Proxy-based logging, drop-in for OpenAI/Anthropic calls. Fastest path to 'I can see my LLM calls'.
LangSmith both Commercial SaaS partial (enterprise tier) yes If you're already on LangChain. Closed source. Self-host requires enterprise contract.
OpenAI Evals eval MIT yes no Reference eval framework. Maintenance pace has slowed (_status as of 2026-06, verify before adopting_). Most teams pick promptfoo or DeepEval instead.
TABLE // AGENTS CHANGES QUARTERLY

Agent Frameworks

Loops, planners, tool-use orchestrators. "Pure Python" is still the right answer surprisingly often.

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Name Paradigm License Language Observability Best fit
LangGraph Graph MIT Python/TS built-in (via LangSmith) Stateful multi-step agents with explicit control flow. Heavy if all you need is a tool loop.
Haystack Pipeline Apache 2.0 Python via library RAG-shaped pipelines with reusable components. Strong document processing. Less agent-y than LangGraph.
CrewAI Multi-agent MIT Python via library Role-based agent teams. Reads well in demos. Production teams often find the abstraction in the way.
AutoGen Multi-agent MIT (Microsoft) Python/.NET via library Conversational multi-agent patterns. v0.4 rewrite changed the API substantially (_status as of 2026-06, check current version_).
OpenAI Agents SDK Multi-agent MIT Python/TS built-in Successor to OpenAI Swarm. Tied to OpenAI's API. Use if you're committed to that provider.
Anthropic Claude Agent SDK Multi-agent MIT Python/TS built-in First-party SDK for Claude agents. MCP integration. Use if you're committed to Anthropic.
Pure Python (no framework) DIY n/a Python DIY A while loop, tool definitions in JSON, direct API calls. Wins more often than people admit.

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