Nucleus Nouns

Nice article Ben! I think the HN crowd would be more familiar by calling those "Entities" but I like the new perspective of all companies only handling two or three of them really well.

I think there is more nuance about it for the SaaS-pocalypse though. I have been talking to hundreds of B2B companies and customers are now vibe coding solutions when they need something that the platform doesn't support: a dashboard, a workflow, or an integration.

And once a B2B customer gets a taste of vibe coding... then it's just a matter of time before they start to think about replacing the entire SaaS completely. I have seen this play over and over again so many times in the last few months, it's honestly shocking.

I am working to find solutions to the SaaSpocalypse but don't want to derail from the main topic, there's more info in my profile if this has been something you're thinking about!

This makes me think of domain models in domain-driven design. Very useful to think about what these models are and how it makes sense to set them up & relate them in your area of work.

Makes me wonder if a similar level of analysis was done in reverse to conceive these, hopefully not word yahtzee. At least they don't end with "ly" - the horror.

Identifying the right taxonomy is not only an exercise in naming things, but also building the appropriate data structures and systems in your programs. I think this exercise is incomplete in the absence of studying how these nouns interact with one another.

I don't think that a loose-hanging 'payment intent' evokes a particular emotion, without its constituents' (credit cards, direct debits, cryptocurrencies) relationship to other nouns (customers, invoices, taxes, countries).

Kinda feels like identifying the key user stories with a bit too much naval gazing at the implementation.

That said, the implementations start to gain their own weight as user expectation grows to meet the implementation. I suppose the noun thinking is not entirely frivolous for an established app with expected core workflows and design language.

Something frustrating is when a company is being _clever_ with their nouns. Sometimes it's relatively innocuous, but spending time remembering what unique name I should be searching for instead of something obvious is not my idea of a good time.

Really cool framing, never saw this broken down this way

Makes me wonder if a similar level of analysis was done in reverse to conceive these, hopefully not word yahtzee. At least they don't end with "ly" - the horror.

Kinda feels like identifying the key user stories with a bit too much naval gazing at the implementation.

This is a great point. I did bring up the relationship exercise in the post, but admittedly I didn't give it enough respect.

In college, my database teacher told us to design a database with at least 50 tables and 100 relationships by the end of the lecture. "It will be easier than you think", he said. And it was! And I thank him for that, because that lecture alone probably got me through more progress in product design discussions than anything else.

This makes me think of domain models in domain-driven design. Very useful to think about what these models are and how it makes sense to set them up & relate them in your area of work.

Never heard of this! This would’ve saved me a blog post. I tried all sorts of queries to see if this philosophy existed, and “domain” didn’t pop up in my head. Thank you!

Nice article Ben! I think the HN crowd would be more familiar by calling those "Entities" but I like the new perspective of all companies only handling two or three of them really well.

I am working to find solutions to the SaaSpocalypse but don't want to derail from the main topic, there's more info in my profile if this has been something you're thinking about!

Something I'm really good at is ending my articles with half-baked ideas :) so thank you for challenging it

Regarding "entities", totally understand. I like to write in ways that my mom would understand- not the HN community. In fact, I have a post called "Everything is a Spreadsheet", where I explicitly defined that Entity<->Noun relationship. Should have linked it!

Back to the Saaspocalypse... my startup is reckoning with this like all others. My next blog post will be titled "What's Preventing Me from Building Your App in a Weekend?". The ultimate "what's your moat" question. I think every SaaS should be forced to answer this on their marketing site. Thinking aloud, I'm considering good answers companies can say to this question... I think a perfectly legitimate answer is still "our prompts are better than your prompts". There are some companies where I simply believe the founders/engineers when they say they understand the problem better than I, because they've explored it more deeply. This is kinda what I was hinting at at the end... softwares that go mega-vertical in one or two nouns accrue more subject matter expertise than I ever will. Thus, that gives me more reason to trust their infrastructure, their configurations, and their prompts. This is not new but rather an extension of what created the SaaS economy in the first place.

I will definitely check out your profile- thank you for the thoughtful reply!

Never heard of this! This would’ve saved me a blog post. I tried all sorts of queries to see if this philosophy existed, and “domain” didn’t pop up in my head. Thank you!

Something I'm really good at is ending my articles with half-baked ideas :) so thank you for challenging it

I will definitely check out your profile- thank you for the thoughtful reply!

Oh yeah the SaaS-pocalypse is so new and there are so many different ways to try and understand and tackle it. Scary but exciting times!

> The ultimate "what's your moat" question

One effective moat might be "Your LLM has never been trained on our closed source codebase."

This is a great point. I did bring up the relationship exercise in the post, but admittedly I didn't give it enough respect.

> The ultimate "what's your moat" question

One effective moat might be "Your LLM has never been trained on our closed source codebase."

Oh yeah the SaaS-pocalypse is so new and there are so many different ways to try and understand and tackle it. Scary but exciting times!

April 10, 2026 • 2 min read •

Consider the “nouns” that live inside an app of your choice:

nouns

You can spend hours building a list for just one app. But the more interesting exercise is weighting the nouns in the app- considering which ones have the most “gravity” from the eyes of the user:

nucleus-nouns

You quickly realize that most apps, even the multi-billion dollar ones, revolve around one or two nouns- I like calling these nucleus nouns. Every other noun is a “satellite”.

Nucleus nouns are how I think about apps. Whenever I’m learning an app for the first time, I consciously build out this gravity model. It’s an easy way to cut through the bullshit. I don’t care that your app “optimizes sales efficiency with streamlined processes”. Fuck that. Oh? Your nucleus noun is “Email”? Got it. Now we’re getting somewhere.

Companies with a firm understanding of their nucleus nouns can use them as weapons. They make them part of their brand: ✨ the company that knows X better than anyone else ✨. If companies lose sight of it, the customer feels it:

If nucleus nouns are not represented in your marketing materials, buyers feel it.
If nucleus nouns are not at the top of your API documentation, engineers feel it.
If nucleus nouns don’t impact hiring decisions, expertise will crumble.

Nucleus nouns may seem obvious to many readers. Those that understand the basics of database design might find this second nature. But, I have experienced major communication breakthroughs with team members of all technical abilities by explicitly listing out the “nouns in scope” for a new project.

When starting a new project, list out the nouns with your team. Then, consider this:

Are only existing nouns impacted, not new ones? If so, awesome, let’s move fast and break things.
Are any satellite nouns introduced? If so, alright, let’s consider its relationships, UX, and see if the business value justifies these new nouns.
Are any nucleus nouns introduced? If so, stop everything. Call in the CEO. Rip out the ayahuasca. This decision could change everything.

I’m reminded of Dylan Fields’ reflection of Figma’s release of Figjam: its second product behind its flagship “Design” offering. For an ambitious tech executive, Dylan was awfully pensive about working on a second product (Figjam was released 9 years after Figma’s creation in 2012). I think it was the recognition that a new nucleus creates inertia¹: huge upside if it works, but at what cost?

I’m optimistic in the apps that maintain a uni- or duo-nucleus nouns strategy. Resend is nailing email automation. Plaid is nailing bank linking. To me, this is craft: having the discipline to stick to your nucleus noun and go mega vertical with it. Explore all its quirks and edge cases. Honestly, I think this is the most likely way to win in the SaaSpocalypse. Being “okay” at a lot of things won’t cut it anymore. Your market can vibecode “okay” in a weekend. Craft, focus, and expertise are your moats. I guess some things don’t change.

¹ Shoutout Three-Body Problem!

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