What is Defect Lifecycle?
The defect lifecycle (also called the bug lifecycle) is the series of stages a defect passes through from initial discovery to final closure, typically including New, Assigned, Open, Fixed, Verified, and Closed.
Free to start · 7-day trial on paid plans
In depth.
When a tester discovers a defect, it enters the lifecycle as New. A lead or triage team reviews it and either assigns it to a developer (Assigned), rejects it as not-a-bug, or defers it. Once the developer starts working on it, it moves to Open, then Fixed when a code change is submitted. The QA team verifies the fix in the build, and if the defect no longer reproduces, it moves to Verified and finally Closed. If the fix is incomplete, it is Reopened.
A strong bug report accelerates every stage. It includes a descriptive title, environment details, precise reproduction steps, expected versus actual behavior, severity and priority, and supporting evidence (screenshots, logs, network traces). Teams that write poor bug reports waste cycles on back-and-forth clarification.
Defect triage is the process of prioritizing the backlog. Teams typically triage based on severity (impact on the user), priority (business urgency), and frequency (how many users are affected). Effective triage prevents low-impact bugs from blocking high-impact work and ensures critical issues get attention immediately.
Why interviewers ask about this.
Interviewers ask about the defect lifecycle to assess your process maturity. Knowing the stages shows you understand not just finding bugs but managing them through resolution.
Example scenario.
A tester files a bug: "Checkout fails when cart contains more than 50 items." It is triaged as Severity-High, Priority-Medium because it affects edge-case users. The developer fixes the cart-size query, the tester verifies in staging, and the defect moves to Closed in one sprint.
Interview tip.
Go beyond listing stages. Discuss how you write effective bug reports, your approach to triage meetings, and how you handle disputes about severity versus priority.
Related Terms
Explore related glossary terms to deepen your understanding.
Related Resources
Dive deeper with these related interview prep pages.
Free QA career tools, no account needed
Instant and private, everything runs in your browser. Try them before you sign up.
QA Resume Checker
Instant 0-100 score on automation keywords, impact, and ATS formatting.
QA Cover Letter Generator
A tailored 3-paragraph QA cover letter from your resume and a job post.
QA Application Tracker
Drag-and-drop kanban to track every QA application from Applied to Offer.
QA Take-Home Test Generator
A realistic take-home assignment with a scenario, tasks, and a rubric.
QA LinkedIn Headline Generator
A recruiter-searchable headline, About section, and skills list.
QA STAR Story Builder
Structure a QA behavioral answer with the STAR method and instant checks.
QA Bug Report Generator
Build a clean, reproducible bug report for Markdown, Jira, or plain text.
Boundary Value Analysis Generator
Generate boundary value and equivalence partitioning test cases from a range.
QA Metrics Calculator
Calculate DRE, defect leakage, defect density, and pass rate with interpretation.
QA Test Plan Generator
Build a structured test plan (scope, approach, criteria, risks) in Markdown.
QA Salary Calculator
Estimate QA, SDET, and automation tester pay by level, market, and skills.
QA Offer Evaluator
See total comp, a counter range, and a ready-to-send negotiation message.
Ready to Ace Your QA Interview?
Practice explaining defect lifecycle and other key concepts with our AI interviewer.
Join 1,200+ QA engineers already practicing with AssertHired.
Start your free QA interviewCurious how it works first? See the QA mock interview