Solve the dog poop problem

Q: Solve the dog poop problem.

A product-sense question that tests viability, not UX. Who pays, does the economics work, and why does the $250 NYC fine produce 2 tickets a year?

This question filters for candidates who understand that a product with no buyer is not a product. The strong answer treats enforcement as the real constraint, identifies the building manager (not the city, not the dog owner) as the payer, and arrives at a B2B solution grounded in unit economics. The weak answer sketches a crowdsourced shame app and calls it done.

Clarify scope first

Three completely different problems hide under this prompt: public sidewalk fouling in a dense city, indoor house-training failures, and shared-property fouling in apartment buildings and HOAs. Say which one you are solving and why. The public sidewalk framing in a city like NYC is the most interesting because viability is hardest there, and the enforcement paradox makes it a real systems problem rather than a design exercise.

The enforcement paradox

NYC already has a $250 maximum fine and a legal requirement to pick up after your dog. The problem: only 2 summonses for failure to remove canine waste were issued in all of 2025, and 13 in 2024, because the law requires a sanitation officer to personally witness the act in real time. DSNY ran weeklong enforcement blitzes in Washington Heights, Harlem, Morningside Heights, and Flatbush in 2025 and issued zero summonses.

Meanwhile, NYC 311 received 1,950 dog-waste complaints in 2025 (up from 1,750 the prior year), with Washington Heights zip code 10032 seeing a 740% year-over-year increase. An estimated 600,000 dogs in NYC produce roughly 150,000 lbs of waste per day. The ratio of enforcement to problem is nearly zero.

Any product that routes complaints into that void is not a product. A crowdsourced reporting app with photo upload and karma points is just another path into the same DSNY inbox with no mechanism to act.

Who actually pays

Building owners and property managers. They pay cleaning crews to pressure-wash entryways, field tenant complaints about shared spaces, and watch building ratings suffer. Pooprints (BioPet Vet Lab) already charges buildings $30 to $50 per dog for DNA waste registration. That proves the buyer exists and has demonstrated willingness to pay.
Business Improvement Districts and parks conservancies. Organized buyers with real budgets, faster sales cycles than government, and a clear stake in foot-traffic quality.
DSNY and city government. A real buyer at scale, but slow procurement makes them a later wedge, not a launch market.

Dog owners are a user, not the payer. Design for the building manager. Build something that nudges the dog owner as a downstream effect.

The supply-side gap worth naming

311 data shows that zip codes with the most complaints also have the fewest free bag dispensers. Part of the problem is not behavior, it is supply. Naming this earns points for specificity over the generic “people are inconsiderate” read.

Prioritized solution

A smart waste station: a combined dispenser and computer-vision camera module installed at building entries and common areas. The CV component logs incidents without requiring a human witness, generating photo-verified reports that property managers can use for building-level warnings and, when thresholds are crossed, route to DSNY’s 311 system as actionable evidence.

In 2026, edge-inference cameras are cheap enough to deploy at building scale. This directly breaks the “witnessed in real time” bottleneck that makes the existing fine meaningless. Computer vision was the feasibility constraint in 2024. It is not the constraint now.

Revenue: hardware lease plus a SaaS data subscription plus DNA registry kit upsell (partnered with or competing against Pooprints). Buildings in high-complaint zip codes already pay for weekly pressure-washing; that cleaning cost alone justifies a $200/month subscription.

North star metric: verified incidents per building per month. Launch market: co-op and condo buildings in Manhattan and Brooklyn with active HOAs. Fastest sales cycle, highest willingness to pay, dense enough to validate hardware unit economics quickly.

Strong answer

strong

"I want to clarify scope first: public sidewalk fouling in a dense urban environment like NYC, because that is where viability is hardest. The core constraint is not technology or user empathy, it is the enforcement paradox. NYC has a $250 fine and a legal requirement to pick up. But only 2 summonses were issued in all of 2025, because the law requires a sanitation officer to personally witness the act. DSNY enforcement blitzes in Washington Heights and Harlem yielded zero tickets. Any product that routes more complaints into that same void is not solving the problem.

The buyer is not the city and it is not the dog owner. It is the building manager who pays cleaning crews, fields tenant complaints, and watches building ratings. Pooprints already charges buildings $30 to $50 per dog for DNA waste registration, which proves the market exists. I would build a smart waste station: a dispenser plus a CV-camera module that logs incidents without requiring a human witness, generates verified reports for property managers, and routes evidence to DSNY when thresholds are crossed. In 2026, edge-inference cameras are cheap enough to deploy at building scale. Revenue is hardware lease plus SaaS plus DNA kit upsell. North star: verified incidents per building per month. Launch market: co-op and condo buildings in Manhattan with active HOAs, where the cleaning-cost savings clearly exceed the product cost."

Weak answer

weak

Scopes to "people don't pick up in NYC streets," proposes a crowdsourced reporting app, sketches features (photo upload, GPS tag, city worker notification, karma points), picks "complaints resolved" as the north star. Why it fails: it never asks who funds this or why they would. Cities have not paid for civic shame apps at scale. Dog owners have no incentive to download an app that gets them fined. The report-your-neighbor dynamic has poor retention and real harassment risk. It treats an enforcement problem as a UX problem, and routes 1,950 annual complaints into the same DSNY inbox that already produces 2 summonses a year.

What the interviewer is evaluating

Viability as the primary lens. The question sounds like a design exercise but it is a business exercise. The interviewer is listening for: do you name the enforcement gap before proposing solutions, do you find the buyer with a real P&L motive rather than assuming government or altruism, and does your 2026 framing reflect that feasibility is no longer the interesting constraint. CV, DNA matching, and edge inference are all cheap and deployable. The remaining question is whether the building owner’s cleaning-cost savings exceed the product cost. In high-complaint zip codes in NYC, they do.