AI gateways
Portkey, OpenRouter, LiteLLM Proxy, Cloudflare AI Gateway, Kong AI Gateway, Helicone — one endpoint, many providers.
Orchestration & workflow infra
Inngest, Temporal, Trigger.dev, Restate, Hatchet — running long-running AI workflows reliably.
Agent runtimes & sandboxes
E2B, Modal sandboxes, Daytona, CodeSandbox, Anthropic's code execution tool — secure environments where agents can actually run code.
Batch inference
OpenAI Batch, Anthropic Message Batches, Gemini batch — half-price inference when you can wait, plus the schedulers that drive them.
Voice infrastructure
OpenAI Realtime, Gemini Live, Vapi, Retell, ElevenLabs, Cartesia, Deepgram, LiveKit — building voice-native AI features.
Realtime voice — the engineering details
WebRTC handshake, ephemeral keys, session events, VAD and turn-taking, interruption, latency budget, telephony — the implementation depth behind "in-app voice agent."
Fine-tuning platforms
OpenAI fine-tuning, Together, Modal, Hugging Face, Unsloth, Predibase — where (and when) to fine-tune.