Startup & Product Glossary: Terms Every Solo Founder Should Know

Running a startup solo means switching context constantly: metrics review in the morning, product decisions at noon, launch prep in the afternoon. This glossary collects the terms that come up most in daily standups, retrospectives, and strategy sessions — so you can read and write them without stopping to look things up.

Organized by domain. Jump to what you need.

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1. Business Metrics

Abbreviation	Full Name	One-line meaning
NSM	North Star Metric	The single number that best captures your product’s core value delivery
OKR	Objective + Key Results	Quarterly goal (O) + 3 or fewer measurable outcomes (KR)
KPI	Key Performance Indicator	Operational metrics tracked more frequently than OKRs
MRR	Monthly Recurring Revenue	Monthly subscription revenue — excludes one-time payments
ARR	Annual Recurring Revenue	MRR × 12
DAU	Daily Active Users	Unique users active in a given day
MAU	Monthly Active Users	Unique users active in a given month
LTV	Lifetime Value	Total revenue a single user generates over their lifetime
CAC	Customer Acquisition Cost	Total cost to acquire one paying customer
TAM	Total Addressable Market	Maximum size of the market you could serve
WTP	Willingness to Pay	The price threshold validated before building (₩9,900? ₩30,000?)
D7 / D30 / D60 / D90	Day 7 / 30 / 60 / 90	Measurement checkpoints after launch for retention and KPI tracking
retention	—	Percentage of users who return after N days (e.g., D7 retention 30% = 30% still active 7 days post-launch)
funnel	—	Step-by-step user conversion flow (e.g., install → first action → paid upgrade)
activation	—	User completes the core action at least once
conversion	—	Rate of moving from one funnel stage to the next (e.g., free → paid)
close rate	—	Percentage of sales conversations that result in a purchase
ad-LTV	Ad-based LTV	LTV driven by ad revenue rather than subscriptions — typically a hypercasual game model

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2. Decision-Making & Strategy

Term	Meaning
kill criteria	Pre-defined conditions that trigger shutting down a project — defined before you start, so the decision is data-driven not emotional
kill signal	A data point that satisfies kill criteria (e.g., D7: 0 of 5 users retained → wrong message or wrong ICP)
green signal	A data point that clears a go-ahead threshold (e.g., ≥2 activations → proceed to next stage)
polish trap	The pattern of refining a product past the point of necessity before validating with real users — revenue-free polish is value-zero
pivot	Changing direction after a hypothesis fails (e.g., B2C → B2B)
wedge	The narrow, sharp entry point into a larger market
moat	A sustainable competitive advantage competitors can’t easily replicate (data accumulation, network effects, brand)
flywheel	A self-reinforcing feedback loop that accelerates over time (users↑ → data↑ → accuracy↑ → users↑)
bootstrap	Growing entirely on self-generated cash flow without external funding
venture-scale	Revenue potential large enough to justify VC funding (typically hundreds of millions ARR ceiling)
anti-goal	An explicit “we will NOT do this” commitment — keeps scope from drifting
JTBD	Jobs To Be Done — the underlying goal a user “hires” your product to accomplish
MECE	Mutually Exclusive, Collectively Exhaustive — a framework for classification with no overlaps and no gaps
Go / Hold / Drop	Project status: continue / maintain without new features / retire
hold mode	No new feature development; monitoring and notifications only

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3. Users & Market

Term	Meaning
ICP	Ideal Customer Profile — the archetype of your best first customer
gatekeeper	Someone who influences adoption without being the direct end user (e.g., a therapist recommending an app to a family)
endorsement	A credible recommendation from an authority — more effective than broad cold outreach
cold outreach	Contacting strangers directly via DM or email with no prior relationship
warm intro	An introduction through a mutual contact
pre-screen	Qualifying a potential user for ICP fit and WTP before investing time
D3 returned	User returned within 3 days of first use — a strong early signal of genuine engagement

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4. Product Stages & Launch

Term	Meaning
P0	Launch-blocking bug — must be fixed before shipping
P1	Pre-launch fix if possible, not strictly required
P2	Post-launch fix — deferred deliberately
ship-blocker	Any bug or unresolved decision that prevents shipping (equivalent to P0)
pre-launch	The stage immediately before going live to real users
staging	A production-equivalent environment for final verification before deploy
prod / production	The live environment real users access
listing	The product’s public page on an app store or marketplace
smoke test	A quick end-to-end check that the critical path works
gauntlet	A full scenario-by-scenario QA pass before launch
TestFlight	Apple’s iOS beta distribution channel
beta	Limited-access pre-release testing with real users
rollback	Reverting to a previous version after a bad deploy
hot patch	An emergency fix deployed to production immediately after a critical issue

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5. Technical Terms

Term	Meaning
PWA	Progressive Web App — web app that can be added to the home screen and works offline
Service Worker	Background script responsible for caching and offline functionality in a PWA
OAuth	Standard for delegating authentication to external services (Google, Shopify, etc.)
webhook	A callback where an external service POSTs to your server when an event occurs
idempotency	Property where sending the same request multiple times produces the same result as sending it once
dedup	De-duplication — removing repeated or redundant records
atomic update	A write operation that completes as a single unit with no race condition exposure
race condition	A bug caused by concurrent requests interfering with each other (e.g., credit double-spend)
funnel event	A tracked analytics event corresponding to a step in the conversion funnel
on-device	Processing that happens entirely on the user’s device — no data sent to a server
inferenceMs	Time (in milliseconds) for a single ML model inference pass
p50 / p95	50th / 95th percentile latency — more informative than averages for tail-latency issues
bundle	The combined output file produced by a bundler (esbuild, webpack, Rollup)
externalize	Excluding a library from the bundle and loading it at runtime instead — reduces bundle size
localStorage	Browser key-value store that persists across sessions
standalone mode	PWA launched from the home screen, without the browser’s address bar or tabs
flaky test	A test that produces inconsistent results without any code change
dependency	A task ordering constraint: task A must complete before task B can start

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6. Common Tools by Category

Category	Tools
Hosting / Deploy	Vercel (web apps, Next.js, static sites)
Backend / Database	Supabase (PostgreSQL + Auth + Storage), Prisma (TypeScript ORM)
Payments	Shopify Billing API (app subscriptions), Stripe (direct payments), Gumroad (digital products)
Analytics	Plausible (privacy-first web), Firebase Analytics (mobile)
Mobile Deployment	TestFlight (iOS beta), App Store Connect, Google Play Console
UI Components	Shopify Polaris
Mobile Framework	Flutter (cross-platform Dart)
Bundlers	esbuild, Rollup
AI / ML Runtimes	TFLite (mobile inference), ONNX

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7. Quick Abbreviation Reference

Abbreviation	Meaning
B2B / B2C	Business-to-Business / Business-to-Consumer
GTM	Go-to-Market — strategy for reaching customers
SaaS	Software as a Service — subscription-based software
ASD	Autism Spectrum Disorder
ABA	Applied Behavior Analysis (therapy method for ASD)
EQ	Emotional Quotient — emotional intelligence
KST	Korea Standard Time (UTC+9)
carousel	Horizontally scrollable UI element
modal	An overlay dialog that appears above the main content
toast	A temporary notification that auto-dismisses (typically bottom or top of screen)
placeholder	Temporary value standing in for a real one (e.g., __PROD_URL__)
prepaid	Payment collected before service is rendered

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How to Use This

This glossary is meant to be a quick lookup, not a reading exercise. In practice:

• Metrics conversations: anchor everything to MRR or your NSM. Don’t mix in ARR until MRR is meaningful.
• Strategy calls: state kill criteria before committing. “We’ll kill this if D7 is 0/5” is a decision; “let’s see how it goes” is not.
• Bug triage: label every open issue P0/P1/P2 before a launch. Unlabeled issues always inflate scope.
• User research: confirm ICP and WTP before building. One endorsed user beats ten cold-outreach contacts.

Keep the glossary alive — add terms as they appear in your work, and note why a term was added so future-you has context.