Does the HN community have examples of this that doesn't come from someone selling AI tooling? I'm asking as someone who makes and sells a vertical SaaS, and we’ve seen no evidence of it yet. So far, we’ve been able to reduce accounting, legal and consultant spending significantly, but our horizontal SaaS spending is going up due to lots of cool AI subscriptions (Claude Code etc.)
Cool useful widget - A simple multi city clock homepage which is totally offline https://x.com/jharohit/status/1945756661706330574
vs.
A full blown NDA tracker which uses uploaded signed NDAs to process using gemini 2.5flash, metadata stored in Firebase and then a lightweight table to list all (incl when some are expiring in next 6 months) and what are key items to keep an eye out for, key details (name, company, country, counterparty, etc). NextJS deployed app on standard VM on office server (no replit tho). Will open source this shortly.
Most of them are garbage, overly complex or clunky, and all you really need are workflows that map to your specific needs.
MS teams is horizontal. Send files, real time chat, channels based around access. Integral with general tools like Office and thus you're paying for more.
Slack is more vertical. It plugs well into integrations, people can write their own alerts. Discord is for games and gaming communities.
Full vertical - I helped to sell one for Asian hospitals. Hospitals were building their own comm system because Slack didn't have the fine grained access for patient data. Also Asians took stickers seriously. You can't just give a doctor a thumbs up frog emoji on their message to acknowledge. It had to take significant message space.
Not every tool is going to be HIPAA compliant, or the equivalent in other countries.
Slack does not come bundled with a spreadsheet and word processor though. MS Teams does - that's your horizontal. People who buy Slack generally don't buy Word.
It's a common strategy for a startup to go vertical, then horizontal. Slack was in the business of replacing IRC at first (hence the # logo), but kept going deeper.
HIPAA compliance is another vertical. It's not worth it for Slack to go after hospitals; it's a customer channel they don't understand or sell to. The apps that do hospital won't go after Slack's customers either. But both will go after the ones using MS Teams, email, or WhatsApp.
Another example is payment gateways. Stripe covers 46 countries. Yet nearly every country and region has their own localized payment gateway. Because Stripe doesn't have the depth to cover all the channels, every bank, every e-wallet. E-wallets are lighter than bank accounts, making them some of the most tightly regulated, especially for money laundering and countries with more crime/corruption. Stripe won't do these; most people with e-wallets have bank accounts and credit cards. It's a lot of work just to deal with one country, too much to cover 46 countries.
Vertical: industry specific (functionality that can only be used in one or a few industries). The ultimate case of this would be a completely custom solution a bank uses to do x, with a custom integration to their databases etc.
Horizontal: Can be used by many industries as they all need it (accounting software, communication & marketing etc.) Office 365 or Slack are classic examples.
1.
- Horizontal = broad
- vertical = niche
2.
- horizontal = notion solving a specific problem and solving others via integration with other products
- vertical = a company like microsoft that solves a range of problems through directly integrated 1st party products.