AI for System Design
5 min read
Tech LeadCto
Software Arch
Use AI to stress-test your design. 'What are the failure modes?' 'How does this scale?' You make the call.
Cloud Arch
AI knows common patterns. Use it for cost/compliance trade-offs. Verify against your actual cloud provider docs.
AI for System Design
TL;DR
- AI can be a strong thinking partner for architecture: brainstorm options, identify risks, compare trade-offs.
- It cannot make the final call. It doesn't know your org, team, or constraints.
- Use it to expand your thinking, not to replace it.
System design is judgment-heavy. AI can't attend your design review. But it can help you prepare, stress-test, and fill gaps before you get there.
What AI Is Good At
- Generating options — "What are 3 ways to add caching to this system?" You get a starting menu.
- Trade-off analysis — "Compare event-driven vs. request-response for this use case." Structured pros/cons.
- Identifying risks — "What are the failure modes of this design?" Often surfaces things you hadn't considered.
- Pattern recall — "What's the standard pattern for X?" CQRS, saga, circuit breaker, etc.
- Documentation — "Turn this whiteboard sketch into an architecture doc." Draft, not final.
What AI Can't Do
- Know your constraints — Team size, budget, legacy systems, compliance, politics. You supply that.
- Make the decision — "We should use Kafka" vs "We should use SQS" depends on your context. AI can't weigh it.
- Account for org fit — "We don't have Kafka expertise" — AI doesn't know that.
- Invent novel solutions — AI recombines known patterns. Truly novel architectures are still human.
A Practical Workflow
- Draft your design — Rough architecture, main components, data flow.
- Paste into AI — "Here's my design. What am I missing? What are the risks?"
- Iterate — "We have to use Postgres, not a new DB." "What changes?"
- Stress-test — "How does this fail under load? Under partial outage?"
- You decide — Take the feedback. Make the call. Own it.
Prompt Patterns for Design
- "Compare approach A and B for [goal]. Consider: scale, ops complexity, cost. We're a team of 5."
- "What are the failure modes of this design? Rank by likelihood and impact."
- "We're adding [feature] to [existing system]. What's the least disruptive approach?"
- "Explain the trade-offs of [pattern] (e.g., event sourcing) for our use case: [brief description]."
Common Pitfalls
- Over-engineering — AI loves to suggest the "right" pattern. Sometimes simple is better. Push back.
- Outdated advice — Managed services and cloud offerings change. Verify "best practices" against current docs.
- Ignoring humans — The best design is one your team can build and operate. AI doesn't know your people.
You design a system. You present at the review. Someone asks 'What about failure mode X?' You hadn't thought of it. Rework. Second meeting.
Click "Design → AI stress-test → you decide → review" to see the difference →
Quick Check
AI suggests using Kafka for your event pipeline. Your team has zero Kafka experience. What's the right approach?
Do This Next
- Run your next design through AI — Paste a high-level description. Ask for risks and alternatives. See what it surfaces.
- Create a "design review" prompt — Template that includes your usual constraints (team size, cloud provider, latency requirements). Reuse it.