Will open-source software replace SaaS?

and what we can learn from meal delivery services

SAP rival Odoo, is currently valued at $5.3 billion

Over the last decade SaaS became the dominant model for enterprise software. Every workflow became a subscription: CRM, HR, analytics, marketing, support. Entire companies built around selling access to a UI.

A combination of open-source software, AI agents, and better infrastructure is starting to challenge that model. Instead of buying software, companies are increasingly asking a different question:

Should we just build this ourselves?

One of our customers has done exactly this.

They replaced Salesforce with TwentyCRM. Their entire HR and ERP stack runs through Odoo. And their long-term plan is pretty simple: build most things internally using open-source software.

For years, building internal software was expensive, slow, and fragile. You needed a team of engineers just to recreate something Salesforce or HubSpot already did.

Now that assumption is breaking down.

And the data actually supports this shift. Today 83% of companies already use custom-built software somewhere in their operations, dashboards, internal workflows, automations, integrations , even though most still rely on off-the-shelf tools for standard functions.

At the same time, the global market for custom software development is roughly $43B today and projected to reach about $146B by 2030.

That kind of growth doesn’t happen unless companies are increasingly deciding to build more software themselves, and you can start to see this shift in the tools they’re choosing.

One of the clearest examples is open-source business software, especially platforms like Odoo.

Odoo has quietly become one of the fastest-growing ERP platforms in the world. What makes it interesting is not just that it’s open source , is that it behaves more like a software framework than a product.

You get accounting, CRM, invoicing, inventory, support, etc.

But the real point is that companies can modify it endlessly. Instead of paying tens or hundreds of thousands a year for multiple SaaS tools, teams can start with Odoo and customize the workflows they actually need.

The second signal is companies aggressively reducing their SaaS footprint.

A widely discussed example is Klarna. During its internal AI transformation the company removed over 1,200 external SaaS tools while automating large parts of internal workflows.

At the same time, Klarna deployed an AI assistant that handled 2.3 million customer conversations in its first month, doing the work of roughly 700 support agents while cutting resolution time from 11 minutes to 2 minutes.

The point here isn’t that AI replaces humans.

The interesting thing is that AI replaces software interfaces.

Instead of humans clicking through tools, agents interact directly with APIs and systems, orchestrating workflows across multiple products simultaneously.

When that happens, the UI layer, the thing SaaS companies sell, becomes less important.

But the easiest way I’ve found to think about this shift is actually food.

The food world has three basic models

• Restaurants

• Meal kits

• Grocery stores.

Each solves the same problem (feeding people) but in completely different ways.

And oddly enough, these map almost perfectly to how software is evolving.

1. Restaurants (Traditional SaaS)

Restaurants are the fully packaged experience.

You walk in, someone else cooks the meal, someone else designs the menu, someone else handles the logistics. Your only job is to consume the result.

Uber Eats and delivery apps pushed this even further. Now you can outsource cooking entirely.

This is basically what SaaS did for software. SaaS says: don’t worry about infrastructure, workflows, hosting, updates, engineering; we’ve already built the system. Just log in and use it.

Salesforce, HubSpot, Zendesk, these are restaurants.

And this made sense. Running your own software was like running your own restaurant kitchen, expensive and complicated. And in many cases, this is still the right choice. If something is truly best-in-class, it’s often cheaper to buy the experience rather than build it.

2. Meal delivery kits (Open-source platforms)

Then meal delivery services appeared: HelloFresh, Blue Apron, etc.

They changed the model.

Instead of cooking everything for you, they give you ingredients + recipes.

You still cook the meal, but the hard part, planning and sourcing, is done.

The model clearly resonated. The global meal-kit market is roughly $25–33B today and projected to exceed $70B over the next decade. In the U.S. alone it was about $10.4B in 2023 and is expected to more than double by 2030.

That’s what open-source platforms like Odoo or Twenty CRM represent.

They give you the structure of enterprise software, but let you modify it however you want.

You aren’t locked into someone else’s workflow.

3. Grocery shopping (build-it-yourself software)

Finally there’s grocery shopping.

You buy raw ingredients and cook everything yourself.

This used to be the equivalent of building internal tools from scratch, something only large tech companies could afford.

But AI agents are starting to change that too.

Agents can now write code, connect APIs, automate workflows, and operate software directly.

In other words:

AI is making building your own software dramatically easier.

The psychology behind these models is actually quite predictable.

Most people don’t cook every meal themselves, not because they can’t, but because of time, expertise, and convenience.

Restaurants win when people want simplicity.

Meal kits win when people want control but not complexity.

Cooking wins when people want full customization.

Software markets are starting to follow the same pattern.

For years SaaS dominated because it was the easiest option.

But as customization becomes easier (and cheaper) the balance starts shifting.

Companies are realizing something important:

They don’t actually want generic workflows.

They want software that reflects how their business actually works.

AI agents accelerate this shift even further.

Instead of humans navigating software, agents can execute workflows directly across systems, retrieving data, triggering actions, and coordinating tasks.

This changes the economics of software.

Traditional SaaS pricing is built on per-seat subscriptions.

But agents don’t buy seats.

They operate systems.

At the same time, even SaaS companies are moving toward agent-driven architectures. For example Salesforce now runs autonomous agents through its Agentforce platform, and its CEO has said AI already performs 30–50% of internal work inside the company.

That alone tells you something about where things are going.

So where does this leave SaaS?

Probably not dead.

Restaurants still exist. They’re just no longer the only way people eat.

What seems more likely is a shift in the software stack:

• Open-source platforms become the base layer

• AI agents orchestrate workflows on top

• SaaS products become components rather than destinations

Instead of logging into five different tools, companies will have systems that assemble themselves around their workflows.

The UI becomes optional.

The agent becomes the interface.

And software stops looking like products, and starts looking more like infrastructure.

One last thought.

The SaaS era optimized for distribution.

The next era might optimize for adaptability.

Software that can reshape itself around a company will always beat software that forces the company to reshape itself around the tool.

Which is why open source + AI + agents together feel like something bigger than just another technology shift.

It feels like the moment when building software becomes easier than buying it.

And historically, when that happens, markets change very quickly.