LangGraph state machines, n8n business automation, Temporal durable execution, Airflow ML pipelines, HITL patterns, and event-driven AI workflows.
| Tool | Best For | Complexity | HITL |
|---|---|---|---|
| LangGraph | Agent state machines, branching logic | Medium | ✅ interrupt() |
| n8n | Low-code business automation, SaaS integrations, webhook flows | Low | ⚠️ manual approval patterns |
| Temporal.io | Durable long-running workflows | High | ✅ Signals/Queries |
| Apache Airflow | Batch ML pipelines, DAG scheduling | Medium | ⚠️ sensors only |
| Azure Durable Functions | Serverless orchestration on Azure | Medium | ✅ External events |
| Prefect | Python-native MLOps workflow | Low | ⚠️ Limited |
| Celery + Redis | Task queues, distributed worker pools | Medium | ❌ None |
n8n fits the layer between backend services and business process automation. Use it when you need webhook-driven workflows, SaaS integrations, approvals, CRM/email/Slack actions, or scheduled automations without writing every step in Python.
Recommended split: n8n for integration and workflow glue, Python for AI reasoning, APIs, data, and secure execution.
LangGraph models agent workflows as directed graphs. Each node is a function (LLM call, tool use, router). Edges define transitions. State flows through the graph, building up results.
Temporal persists workflow state automatically. If a worker crashes mid-execution — even hours into a complex agentic workflow — it replays from the last checkpoint automatically.
Apache Airflow is the industry standard for batch ML workflows — scheduled DAGs that run data preprocessing, model training, evaluation, and deployment steps.
Trigger agent workflows from events (document uploaded, ticket created, metric threshold crossed) rather than polling or schedules.
Wait 1s → 2s → 4s → 8s between retries. Add jitter to avoid thundering herd.
Stop calling a failing service after N failures. Re-probe after cooldown period.
Failed messages land in DLQ for manual inspection. Prevents data loss.
Each step has a compensating action. On failure, unwind completed steps in reverse.
Set per-workflow token budgets. Fail gracefully when exceeded instead of running up costs.
Batch embedding calls (2048+ texts at once) instead of one-by-one API calls. 100x cheaper.
Cache LLM responses for identical prompts with semantic cache (e.g., GPTCache). 30-70% cost reduction.
Route simple tasks to gpt-4o-mini ($0.15/1M) and complex to gpt-4o ($5/1M) using a classifier.