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CIRCLES Framework

The CIRCLES Method will ensure that you always give a complete, structured response to any product design or improvement question.

The CIRCLES Method is a 7-step product design framework created by Lewis C. Lin for structuring answers to 'design a product' questions in PM interviews and real discovery work. Each letter maps to a named stage — Comprehend, Identify, Report, Cut, List, Evaluate, Summarize — with defined outputs at every step. It transforms open-ended design prompts into a repeatable process that produces personas, prioritized needs, solution shortlists, and justified recommendations.

By Lewis C. Lin · Free
Specimen 01 · Live diagnosisCIRCLES Framework
Input

“Design a product for senior citizens. It's a classic interview question and I always freeze up and start rambling.”

Diagnosis
I'm your CIRCLES guide — Lewis Lin's 7-step framework for structured product design.
Full transcript ↓
Calibrated referenceagent-skills.ai
The gap

Answer any product design question with a complete, structured 7-step response

CIRCLES is a 7-step acronym that provides a complete scaffold for any product design or feature improvement question. Step 1 (Comprehend) clarifies the product's goal, constraints, and context before any design begins. Step 2 (Identify) segments potential users and selects a primary target persona. Step 3 (Report) surfaces the selected persona's key pain points and jobs-to-be-done. Step 4 (Cut) applies a prioritization lens — typically impact × frequency or impact vs. effort — to isolate the highest-value user need. Step 5 (List) brainstorms 2–4 concrete product or feature solutions. Step 6 (Evaluate) compares those solutions on dimensions of user impact, technical feasibility, and business risk. Step 7 (Summarize) delivers a structured final recommendation with clear rationale. The entire sequence was designed to be repeatable across any product domain — consumer apps, enterprise tools, hardware, or platform features.

The problem

Most PM candidates and early-career product managers have a fatal flaw on design questions: they jump straight to feature ideas without establishing who the user is, what they actually need, or why one solution beats another. The result is an unfocused answer that covers many users poorly, proposes features without prioritization logic, and ends with a vague 'it depends' rather than a clear recommendation. Interviewers — and real stakeholders — lose confidence fast.

The solution

Walk through any product design question — interview prep or real work — using the same 7-step CIRCLES sequence every time: you'll never skip the user, never forget to prioritize, and never end without a justified recommendation.

You bring
  • A product design prompt or feature question (interview question or real work scenario)
  • Any known constraints: platform, audience, business goals, or timeline
  • Your current thinking — even partial ideas or user segments you're already considering
  • The step you're stuck on, if you want to focus on a specific part of the framework
You get
  • A completed CIRCLES Answer Blueprint — structured outputs for all 7 steps
  • A selected user persona with demographics, behaviors, and top pain points
  • A scored Needs Prioritization Matrix ranking user problems by impact × frequency
  • A Solution Comparison Table evaluating 2–4 options on feasibility, user impact, and business risk
  • A polished final recommendation paragraph ready for an interview or stakeholder presentation
In action

Watch the methodology work.

Three specimens from a single real session: the same situation, unaided and calibrated, the full transcript, and the skill answering live in the channel where the work happens.

Fig.01The same situation, two ways
Specimens A · B
Specimen AVague
Unaided

“You're in a PM interview. The question: 'Design a product for senior citizens.' You start talking about three different user types at once, jump to feature ideas like 'medication reminders and fall detection,' and end with 'it depends on the specific use case.' You never committed to a user, never justified your feature choices, and gave no recommendation. The interviewer says 'interesting' and marks a low score for structure.”

×Vague — nothing concrete to act on.
Specimen BCalibrated
With CIRCLES Framework

“Using CIRCLES, you walk through every step in sequence: you clarify scope (mobile app, quality of life), select homebound seniors 70–85 as your persona with stated rationale, surface social isolation as the top need using impact × frequency scoring, propose three distinct solutions, evaluate each on feasibility and adoption risk, and close with a clear recommendation — the Simplified Video-Call App with family-managed onboarding — and a one-sentence rationale. The interviewer asks a follow-up question. You have a framework for that too.”

Specific, grounded, and ends with one clear next step.
Fig.02A real session, unedited
In-app · assistant
CIRCLES FrameworkClaude
CIRCLES Framework
I'm your CIRCLES guide — Lewis Lin's 7-step framework for structured product design. Give me any product design prompt (an interview question, a real feature challenge, or a product you're scoping), and I'll walk you through every step: comprehend the situation, identify your customer, report their needs, cut to the highest-priority problem, list solutions, evaluate tradeoffs, and summarize a recommendation. What's your prompt?
Design a product for senior citizens. It's a classic interview question and I always freeze up and start rambling.
Perfect — this is one of the canonical CIRCLES prompts. Let's start with Step C: Comprehend the Situation. Before we design anything, we need to clarify scope. A few quick questions: (1) Is this a new standalone product, or an improvement to an existing one? (2) Is there a platform constraint — mobile, web, physical device, voice? (3) Any business goal signals — monetization, safety, social connection? You can answer these yourself, or I can propose reasonable assumptions and we'll move on. What feels right?
Let's say new standalone product, mobile app, and the business goal is improving quality of life. I'll take your assumptions from there.
Great. Assumptions locked: new mobile app, quality-of-life focus. Step I: Identify the Customer. 'Senior citizens' is too broad to design for. Let me segment them: (A) Active, tech-comfortable seniors (60–70, still working or socially active, smartphone users), (B) Homebound or mobility-limited seniors (70–85, reduced independence, caregiver-assisted), (C) Cognitively declining seniors (80+, memory challenges, dependent on family). For a quality-of-life mobile app, I'd recommend targeting Segment B — homebound seniors aged 70–85. They have high unmet needs, are reachable via mobile with caregiver support, and represent a large growing population. Agree, or want to target a different segment?
I like Segment B. Let's go with that.
Step R: Report the Customer's Needs. For homebound seniors aged 70–85, here are their top pain points and jobs-to-be-done: (1) Social isolation — difficulty staying connected with family and friends without tech confidence; (2) Safety anxiety — fear of falls or medical emergencies when alone; (3) Loss of autonomy — dependence on caregivers for basic tasks like medication reminders or appointments; (4) Mental stimulation — boredom and cognitive disengagement with limited outside activity. Now Step C: Cut Through Prioritization. Scoring these by impact × frequency: Social isolation scores highest — it's a daily, emotionally intense pain point that no existing app solves well for this cohort. Safety anxiety is high-impact but already addressed by products like Life Alert and Apple Watch fall detection. I recommend cutting to social connection as the priority need. Does that prioritization make sense to you, or do you see a different scoring?
That makes sense. Social isolation feels like the biggest unmet need. What are the solutions?
Step L: List Solutions. Three distinct options for addressing social isolation for homebound seniors on mobile: (1) Simplified Video-Call App — a stripped-down video calling interface with large buttons, no logins, and family-managed contacts; (2) Daily Life-Sharing Feed — an asynchronous photo/message board where seniors and family members post daily updates without real-time pressure; (3) Caregiver-Coordinated Social Scheduling — a shared calendar where family caregivers schedule visits, calls, and check-ins with automated senior-facing reminders. Step E: Evaluate Tradeoffs — let me run these against feasibility, user impact, and business risk. The Simplified Video-Call App is highest on user impact (real-time connection) but requires technical confidence seniors may lack — adoption risk is real. The Daily Life-Sharing Feed is lower friction, high adoption likelihood, but connection depth is reduced. The Social Scheduling tool has strong caregiver appeal but senior value is indirect. I'd recommend Option 1 — the Simplified Video-Call App — with onboarding co-designed for family members to set up on behalf of seniors. Want the full recommendation paragraph for your answer?
Yes — and honestly, I can see how this would hold together in an interview. Walking through each step made the answer feel much more confident.
Reply to CIRCLES Framework
What the skill is doing
01Situation Comprehension
02Customer Segmentation & Persona Selection
03Needs Prioritization Matrix
Fig.03The same skill, in the channel you already use
WhatsApp · live
9:41
CFCIRCLES Frameworktyping…
Messages are end-to-end encrypted. No one outside of this chat can read them.
Today
Design a product for senior citizens. It's a classic interview question and I always freeze up and start rambling.9:14✓✓
I'm your CIRCLES guide — Lewis Lin's 7-step framework for structured product design.9:14
Message

The same skill, where the work happens.

No new app to learn. The methodology runs over the WhatsApp Business API, so the answer lands as a reply in the thread you’re already in — same rigour, zero context-switch.

Reads the situation, names the pattern, returns one concrete next move.
Delivered in seconds, inside a conversation that already exists.
Specimen · WhatsApp Business API · live
Capabilities

What it does, specifically.

Each capability is a distinct move drawn straight from the source methodology — not a generic assistant guessing.

CapabilityC-01

Situation Comprehension

Before designing anything, CIRCLES demands that you understand what problem you're actually solving. This capability guides you through clarifying the product's goals, constraints, success metrics, and any ambiguities in the prompt — ensuring the rest of your answer is scoped correctly.

Maps directly to Lin's Step C (Comprehend the Situation), which he describes as the most commonly skipped — and most penalized — step in PM interviews.
CapabilityC-02

Customer Segmentation & Persona Selection

You can't design for everyone. This capability walks you through generating a clear user segmentation (e.g., by age, tech comfort, use case, or role) and committing to one primary persona with a stated rationale — the foundation for every subsequent step.

Combines Lin's Step I (Identify the Customer) and Step R (Report the Customer's Needs), which together produce a named persona and a list of that persona's pain points and jobs-to-be-done.
CapabilityC-03

Needs Prioritization Matrix

Not every pain point deserves a product solution. This capability applies a scoring heuristic — impact × frequency by default, or impact vs. effort for feature tradeoffs — to your list of user needs, helping you cut to the one or two highest-value problems worth solving.

Maps to Lin's Step C (Cut Through Prioritization), which requires applying a named scoring framework — not gut instinct — to justify why one need is addressed over others.
CapabilityC-04

Solution Brainstorm

With the highest-priority need locked in, this capability generates 2–4 concrete product or feature solutions — distinct enough to represent real options, specific enough to evaluate. Each solution gets a one-sentence description of how it addresses the target need.

Maps to Lin's Step L (List Solutions), where the expected output is a short, named list of solutions — not a stream-of-consciousness brainstorm — each tethered to the prioritized user need from Step C.
CapabilityC-05

Tradeoff Evaluation & Recommendation Synthesis

The final two CIRCLES steps run together in conversation: first, comparing your solutions on feasibility, user impact, and business risk in a structured table; then synthesizing that analysis into a clear, confident recommendation with rationale. You walk away with a complete answer that any interviewer or stakeholder can follow.

Maps to Lin's Steps E (Evaluate Tradeoffs) and S (Summarize Your Recommendation), which together close the loop — you can't summarize credibly without having done the tradeoff analysis, and the analysis is wasted without a decisive recommendation.
Tested

Graded before it shipped.

Every skill is scored against independent scenarios for methodology fidelity before it goes live — not vibes, a rubric.

What it produces
OutputD-01

CIRCLES Answer Blueprint

A structured 7-section document capturing the output of each CIRCLES step for a specific design prompt — from clarified scope and selected persona through prioritized need, solution shortlist, tradeoff analysis, and final recommendation. Suitable for interview prep review or stakeholder sharing.

OutputD-02

User Persona Card

A focused one-page persona summary for the selected target segment, including demographics, behavioral context, top pain points, and jobs-to-be-done — derived from the Identify and Report steps.

OutputD-03

Needs Prioritization Matrix

A scored table ranking 3–5 user needs by impact × frequency (or an alternate scoring dimension), with the selected 'cut' need highlighted and the rationale for deprioritizing others documented.

OutputD-04

Solution Comparison Table

A side-by-side comparison of 2–4 candidate solutions evaluated across user impact, technical feasibility, and business risk — the direct input to the final recommendation.

The source

Grounded in the original work.

Every answer traces back to a real source and the practitioner who wrote it — not a secondhand summary. Here is the source of record.

Source authorA-01

Lewis C. Lin

Lewis C. Lin is the creator of the CIRCLES Method and author of 'Decode and Conquer: Answers to Product Management Interviews,' the most widely used PM interview prep book in the industry. A Harvard MBA and former PM at Google and Microsoft, he has coached thousands of PM candidates through his books, online courses on Udemy and Coursera, and his PM interview coaching programs.

Status · Inspired by Lewis C. Lin’s work — not yet claimed. Are you Lewis C. Lin?
Primary sourceS-01

Decode and Conquer: Answers to Product Management Interviews

by Lewis C. Lin

Harvard MBA; former PM at Google and Microsoft; author of Decode and Conquer; PM interview instructor on Udemy and Coursera.

Read the original ↗
Citationlewis-lin.com
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At launchI have a PM interview in two days and keep freezing on product design questions. Can you walk me through a CIRCLES answer for 'Design an app for college students'?