Module 9 Lesson 5: When StrandAgents Make Sense
Choosing the right tool. Understanding when to use event-driven strands over complex graphs or crews.
Use Case Selection: When to Choose Strands
We have covered three frameworks. To avoid over-engineering, you must know which one is the "Best Fit" for your specific problem. StrandAgents is not a replacement for LangGraph or CrewAI; it is a specialized tool for High-Volume, Low-Latency tasks.
1. The "Live Feed" Use Case
If your agent is processing a live feed (like a Twitter stream, a Slack channel, or server logs), you need Strands.
- LangGraph: Would be too heavy. You'd be creating and destroying thousands of graphs per minute.
- CrewAI: Would be too slow. You don't need a "team meeting" for every new log line.
- Strands: Perfect. Every log line is an "Event." The Strand does a quick check and moves on.
2. Stateless Transformation
If your task is purely transformational:
- "Given this JSON, convert it to a Human-readable email."
- "Given this audio transcript, extract the action items." Since these tasks don't require "looping" or "long-term memory," a simple Async Strand is the most efficient choice.
3. High-Concurrency Systems
If you are building a tool for 10,000 users, and each user has an agent:
- Stateful systems (LangGraph) will require massive database infrastructure to manage 10,000 concurrent states.
- Stateless Strands can be deployed on AWS Lambda or Google Cloud Functions, scaling to zero and handling the bursts easily.
4. Comparison Summary
| Feature | Use LangGraph if... | Use CrewAI if... | Use StrandAgents if... |
|---|---|---|---|
| Priority | Control & Loops | Team Collaboration | Latency & Scale |
| Logic | Rigid Flowchart | Role-based Creative | Task-based Reactive |
| Speed | Medium | Slow | Fastest |
| Session | Long-running | Project-based | Request-based |
5. The "Hybrid" Reality
In a real enterprise app, you might use BOTH:
- StrandAgent: Acts as the "Traffic Cop" (Front Door). It classify the request and handles simple tasks.
- LangGraph: The StrandAgent triggers a LangGraph ONLY when a complex, multi-turn reasoning task is detected.
Key Takeaways
- Strands are for high-speed, independent, or streaming tasks.
- They are the "Microservices" of the agent world.
- Decoupling agents through events is the key to massive scale.
- When latency is a product feature, choose Streaming Strands.