ElevenLabs·Software Engineer·Onsite - System Design / Architecture·Senior

Senior

Apr 2026

Summary

System design prompt at ElevenLabs for a SWE role, framed as a CTO scenario about automating airline flight rescheduling. Pretty open-ended, which I wasn't fully prepared for.

Questions Asked (1)

You're the CTO of an airline. Flight rescheduling currently happens manually when delays or mechanical issues occur. How would you design a system to automate this process?

System DesignTechnical Trade-offsAdaptability & Ambiguity

Author's notes

I spent the first minute just staring at it.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the scope and constraints of the rescheduling problem, then outline a high-level system architecture that separates concerns: data ingestion, optimization engine, and execution layer. Emphasize trade-offs between automation and human oversight, and discuss how you would handle edge cases and failures.

Pro tip: Acknowledge that full automation is risky; propose a human-in-the-loop system where the algorithm suggests optimal reschedules and a dispatcher approves them, gradually increasing automation as trust builds.

1. Clarify Requirements and Constraints

Ask questions to understand the scale (number of flights, airports), regulatory constraints, and key objectives (minimize delay, cost, passenger impact). Identify what triggers rescheduling and who the stakeholders are.

2. Design High-Level Architecture

Propose a modular system: a data layer that ingests real-time flight status, weather, crew schedules, and maintenance logs; a rules engine for immediate constraints; and an optimization service that computes rescheduling options.

3. Choose Optimization Approach

Discuss algorithms: rule-based for simple cases, and constraint programming or mixed-integer linear programming for complex scenarios. Mention the need for fast computation and the ability to explain decisions.

4. Address Integration and Execution

Explain how the system would integrate with existing airline systems (e.g., crew scheduling, passenger booking) via APIs. Describe how approved reschedules are executed and communicated to affected parties.

5. Plan for Monitoring and Iteration

Outline metrics to track (e.g., reduction in delay minutes, cost savings, passenger satisfaction) and a feedback loop to improve the algorithm. Discuss fallback to manual process if the system fails.

Key Points to Mention

Trade-offs between full automation and human-in-the-loop control
Real-time data integration from multiple sources (weather, crew, maintenance)
Optimization algorithms (e.g., constraint programming, MILP) and their computational complexity
Handling edge cases and failures (e.g., cascading delays, system outages)
Regulatory and safety compliance (e.g., crew rest rules, FAA/EASA regulations)
Scalability and latency requirements for real-time decision making

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.