Service Reliability and Technical Debt Questions

Covers principles and practices for ensuring system reliability while balancing feature delivery and long term code health. Candidates should understand reliability targets and how to express them, such as uptime goals like 99.9 percent or 99.99 percent, and how to define and measure service level indicators and service level objectives. Explain the concept of error budgets, how to allocate and consume them, and how they drive decisions about releases versus reliability work. Include monitoring and observability strategies for detecting and diagnosing reliability issues, incident response and postmortem practices, and metrics to track system health. Discuss identification and categorization of technical debt, methods to prioritize paying down debt versus shipping new features, cost of delay and business impact communication, and processes for tracking and reducing technical debt over time. Show how you would collaborate with product managers, engineering teams, and stakeholders to trade off feature velocity and stability, set policies for error budget usage, and create roadmaps that include reliability improvements.