Kanban
47 bites tagged Kanban — interview questions with model answers, and 60-second explainers.
From an engineer's perspective, when does Cycle Time begin and end?
Tests if you set Cycle Time boundaries to expose wait states past coding. Strong answer: starts at In Progress, ends at Done or production, includes review/test, excludes backlog queues, and distinguishes from Lead Time. Red flag: starting at ticket creation.
Explain Little's Law and its practical application in Kanban
This tests your grasp of the WIP-throughput-lead time relationship in stable flow systems. State Lead Time = WIP / Throughput and show lowering WIP cuts lead time if throughput is flat. Beware claiming more WIP raises throughput without increasing lead time.
What is the primary purpose of a WIP limit in Kanban?
Tests whether you see Kanban as a flow system, not just a board. A great answer says WIP limits constrain multitasking to reduce cycle time and improve throughput by prioritizing finishing over starting. Red flag: saying limits are for tracking progress.
How would you apply Little's Law to optimize Kanban WIP limits?
Tests whether you can operationalize queueing theory in Kanban. A strong answer cites L equals lambda times W, fixes throughput, then solves for a WIP limit that yields a target cycle time.
What does a widening CFD Code Review band indicate?
Tests CFD literacy: a widening Code Review band shows WIP accumulation and a bottleneck. Great answers cite WIP limits, swarming, and policy fixes before hiring. Red flag: mistaking inventory growth for increased throughput.
Design an Upstream Kanban process for product ideas before development
Tests your grasp of pre-commitment demand shaping. A strong answer maps an option-discovery board, defines the commitment point and triage policies, and ties early filtering to reduced downstream variability.
CFD Testing band widens: what does it indicate and what experiments?
This tests flow metric literacy. A widening Testing band means arrivals exceed departures; propose experiments like smaller batches, automation, or dev-test swarming, then measure cycle time. Red flag: blaming testers or demanding headcount without data.
How would you implement Classes of Service in Kanban?
Tests whether you segment work by risk and cost of delay. A strong answer defines explicit policies, visualizes classes with color or lanes, and reserves WIP capacity per class. Red flag: using classes as simple priorities without capacity rules.
Lead Time vs Cycle Time in Kanban and measuring Cycle Time
Tests whether you distinguish customer wait time from active work. Strong answer: Lead Time is request-to-delivery with queues; Cycle Time is active start-to-finish measured from In Progress to Done. Red flag: treating them as synonyms or ignoring wait states.
Describe the initial columns for a new Kanban board and their purpose
Tests whether you understand Kanban as a flow visualization tool. A strong answer names Backlog, To Do, In Progress, and Done, explaining each as a handoff or state change. Red flag: adding too many columns upfront or conflating the board with Scrum.
How would you measure a launched feature's success and impact?
This tests if you link code to business outcomes via agile metrics. A strong answer covers value, quality, satisfaction; names metrics like velocity or cycle time; and uses reports to track progress. Red flag: defining success purely by uptime or bug counts.
When Does Cycle Time Begin and End?
This tests your grasp of process metrics. Define Cycle Time as starting when active work begins ('In Progress') and ending when it's 'done' (code complete/merged), not when the ticket was created. A red flag is confusing this with customer-facing Lead Time.
Explain Little's Law and its application in Kanban
Tests your grasp of flow metrics beyond the formula. A great answer defines the law (Lead Time = WIP / Throughput), explains the trade-offs (e.g., more WIP increases lead time), and shows how to set WIP limits.
What is the purpose of a WIP limit in Kanban?
Tests understanding of Kanban flow optimization. A good answer explains that WIP limits force task completion, which improves flow, reduces context switching, and exposes bottlenecks. A red flag is describing it only as a way to prevent team burnout.
How would you apply Little's Law to a Kanban system?
This tests your ability to use metrics for process improvement. A great answer defines Little's Law for Kanban (Cycle Time = WIP / Throughput), explains how reducing WIP shortens cycle times, and gives a numerical example.
Diagnosing a Widening Code Review Band in a CFD
This tests data interpretation and problem-solving. A great answer defines the bottleneck, hypothesizes causes (capacity, PR size), proposes diagnostics, then offers solutions. A red flag is blaming individuals or jumping to a single, unverified solution.
Design and Implement an Upstream Kanban Process
Tests your understanding of managing demand vs. capability. A great answer defines Upstream Kanban as a pre-commitment filter, outlines board stages and policies, and explains how vetting work improves downstream predictability.
How would you implement Classes of Service in Kanban?
This tests your understanding of risk management and differentiated service delivery. A good answer defines the 4 classes (Expedite, Fixed Date, Standard, Intangible), explains their different pull policies, and gives a risk-based example.
Explain Lead Time vs. Cycle Time on a Kanban board
This tests your grasp of core Kanban flow metrics. Define Lead Time (customer request to delivery) and Cycle Time (work start to finish). Measure Cycle Time from the first 'In Progress' column to 'Done'. Red flag: defining terms without explaining their value.
What columns would you set up on a new Kanban board?
Tests your grasp of workflow visualization, not just Agile terms. A good answer starts with To Do/In Progress/Done, then adds columns like Code Review to mirror the real process, and crucially, mentions setting WIP limits to manage flow and identify…
How would you identify and elevate a team's primary constraint?
This tests your systems thinking beyond local optimization. A great answer follows the 5 Focusing Steps: Identify, Exploit, Subordinate, Elevate, Repeat. A red flag is jumping to 'hire more people' before exploiting the existing constraint and subordinating…
What's the relationship between Cycle Time, WIP, and Throughput?
This tests your grasp of Little's Law. A great answer defines Cycle Time, WIP, and Throughput, states the formula (Cycle Time = WIP / Throughput), and explains why lowering WIP reduces cycle time.
How would you set a WIP limit for code review?
This tests your ability to use data to diagnose a bottleneck and facilitate a solution. A great answer gathers flow metrics, proposes an initial limit based on team size (e.g., N/2), and frames it as an experiment.
When does a task's Cycle Time begin and end?
This tests your practical grasp of process metrics. Define Cycle Time as starting when active work begins ('In Progress') and ending when 'Done' (shippable). Contrast it with Lead Time (request to delivery). A red flag is confusing the two or being too vague.
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