Product Sense interviews don't test how many features you can think of — they test whether you can find the problem truly worth solving within a vague requirement. Core skills: user segmentation thinking, problem reframing (turning 'add a feature' into 'what problem are we solving'), structured reasoning for feature prioritization, and the ability to hold or revise your judgment under follow-up questions.
Strategy interviews don't test whether you can recite frameworks — they test whether you can make judgments with incomplete information. Core skills: market sizing (the practical use of TAM/SAM/SOM, not rote numbers), competitive moat analysis (network effects, switching costs, brand), go/no-go decisions for new markets, and using elimination rather than addition for strategic trade-offs.
Technical PM interviews don't require you to write production code, but you need to be able to read trade-offs. Core skills: API design fundamentals (RESTful, versioning, error handling), high-level system architecture understanding (microservices, database selection, caching), collaboration patterns with engineers (RFC process, technical spec review), and making product decisions under technical constraints.
Agricultural spraying is the one drone application whose unit economics are fully transparent: the billing unit is the fen (about 970 m²), rates run NT$150–300, spraying one fen takes about two minutes, equipment costs NT$300–500k, and even the substitute's price is public (manual spraying, roughly NT$200 per fen). And precisely because anyone can run the arithmetic, everyone did — operators who entered in 2018 sprayed over a thousand hectares a year and cleared over a million; later entrants broke even after two or three years and quit. Licensed operators charge NT$300 per fen; unlicensed ones undercut to NT$150. This is the industry cycle in miniature, compressed into about six years.
I assumed inspection was blocked by beyond-visual-line-of-sight rules the way logistics is. It isn't. Bridge, transmission tower, and high-speed rail viaduct inspection are all running with hard numbers: one bridge went from 8 inspectors, 4 vehicles and 2 days to 5 people, 1 vehicle and half a day with no traffic control at all, at 60% of conventional cost; high-speed rail crews covered at most 700 metres a day on foot and now save 3–5x; a private power plant cut headcount by three quarters and cost by half with no outage required. The reason is that all of these are segmented, fixed-point tasks completable within visual line of sight. What BVLOS actually blocks is continuous long-range routes, not 'inspection' as a category.
I assumed Taiwan had no real drone logistics because it has no BVLOS framework. Wrong: the CAA has approved 10 cases across 24 flight corridors, and the Institute of Transportation has run a six-year PoC → PoS → PoB path since 2020, entering commercial validation in 2025. The way it routes around regulation is the mirror image of inspection — inspection cuts work down to within visual line of sight, logistics gets corridors approved one at a time. And its value isn't being cheaper than a boat: during the typhoon sailing suspensions at Liuqiu, a drone made the crossing in a bit over ten minutes, which is what you have when the boats don't run.
Agricultural spraying runs NT$150–300 per fen, computable to the decimal. Search and rescue has no such number, because a life recovered has no price. That difference determines two things: first, the specification is written by terrain rather than performance — the defining feature of Taiwan's fire agency drones is that they do NOT depend on GPS, because mountain signal drops and they must thread through trees; second, when the legislature moved to cut the budget, the ministry could only point to one man pulled from a flooded river in June. Defending a budget with an anecdote is fragile, and this application has no better weapon.
Hardware runs 35–55% gross margin under permanent DJI price pressure; autonomy software and DaaS subscriptions run 60–80% and recur. Skydio's software subscriptions were already ~30% of revenue in 2023 at a 38% blended margin; India's Garuda had DaaS at 62% of FY24 revenue with a 351-day cash conversion cycle against a defense-heavy peer's 597. Taiwan is almost entirely concentrated in the lowest-margin, most substitutable cell.
The unit of validation is an assumption, not an idea. Kohavi's data shows the industry median experiment success rate is ~10%, which means roughly 22% of 'winning' experiments at p<0.05 are false positives. Sean Ellis's 40% threshold has no publicly available dataset. AI product retention should be baselined at M3 rather than M0, and GRR splits from 23% below $50/mo to 70% above $250/mo.
A Product Builder runs the full loop from problem discovery to design to build, alone. The core difference from a PM: PMs influence execution through authority, Product Builders influence it by directly shipping working products. LinkedIn replaced its APM program with an Associate Product Builder track, and PayFit defined the role back in 2019.