KMP is not another universal remote.  

Imagine you’re building a restaurant franchise. The most important part of your business is your secret sauce. It’s what makes your burgers, your tacos, or your artisanal kale smoothies unique.  

You wouldn’t want one chef in your New York branch making it one way, and another chef in your London branch making it another. That’s a recipe for chaos and, eventually, a visit from Gordon Ramsay.

In the app world, that secret sauce is your business logic.  

It’s all the important stuff that happens behind the scenes: how you calculate shipping costs, how you verify a user’s password, how you determine which cat video to show next.

In a traditional app development model, you’d write this logic twice: once in a language called Swift for your iOS app, and again in a language called Kotlin for your Android app. It’s as inefficient as it sounds.

Kotlin Multiplatform looks at this situation and lets your developers write all that important development logic just once, in a single, shared place. KMP doesn’t try to dictate what your app should look like. It doesn’t force your iOS app to look like an Android app, or vice-versa. It just handles the complicated, non-visual stuff.

The result is that you get to share a huge chunk of your code (often 60-80%) without compromising on the user’s experience. Your app still looks and feels 100% native on both platforms, because the part the user actually touches—the UI—is 100% native.

It’s actually quite clever, and you don’t need a computer science degree to get the gist of it. It boils down to two key ideas: the Shared Module and the Expect/Actual mechanism.

The Shared Module

As we’ve established, the Shared Module is where your developers write all the code that can be, well, shared. This is your business logic, your networking code (how the app talks to the internet), and your database code (how the app remembers things).  

It’s all written in Kotlin, a language that is modern, safe, and generally pleasant to work with, which keeps your developers from getting grumpy.

Once this shared code is written, KMP’s special compiler goes to work. For your Android app, it produces the kind of code that Android has always understood. No drama there. For your iOS app, it does something remarkable: it compiles the Kotlin code into a native iOS library. Your iOS developers can use this shared code as if it were written in Swift. There’s no clunky “bridge” slowing things down.  

It’s like the chef in your London restaurant receiving a perfectly prepared, vacuum-sealed packet of your secret sauce, ready to be used in their native dishes.

The Expect/Actual Mechanism

Of course, not everything can be shared. Sometimes you need to do something that is unique to a specific platform.  

For example, showing a notification on an iPhone is different from showing one on an Android phone. This is where the “Expect/Actual” feature comes in, and it’s a stroke of genius.

In the Shared Module, a developer can write an expect function. This is like the head chef writing in the master recipe, “I expect each restaurant to have a way to toast a bun.” They don’t care how the bun is toasted—maybe the London restaurant has a fancy new bun-toasting machine, while the New York one uses a grill—they just need it to happen.

Then, in the platform-specific code, the developers provide the actual implementation. The Android developer writes the actual code for toasting a bun on Android, and the iOS developer writes the actual code for toasting a bun on iOS. This way, the shared logic can stay clean and blissfully unaware of the platform-specific details, while still having full access to all the native features of the device.  

Now, You Can Even Share the UI (If You Want)

For a long time, the KMP philosophy was strictly about sharing logic. But the world changes, and sometimes you need to get an app out the door yesterday.  

This is where Compose Multiplatform enters the picture. It’s a modern UI toolkit that lets you, if you so choose, share the user interface code as well.  

This is a fantastic option for building a Minimum Viable Product (MVP) at lightning speed. You can build your entire app once—logic, UI, everything—and then, down the road, if you decide you need a super-custom, platform-specific screen, you can just detach that one part and build it natively. It’s like having your cake, eating it too, and then discovering you have a second, backup cake.

But wait, there’s more

Because KMP has become so popular, many famous libraries (like Ktor for networking or SQLDelight for databases) are already written to be "multiplatform." Your developers don't have to reinvent the wheel; they can just plug these into the Shared Module.

For a founder, every technical decision is ultimately a financial decision disguised in developer jargon. The choice of how you build your app affects everything from how much coffee your team consumes to whether you can afford to pay them next month.  

KMP, it turns out, is surprisingly good for the bottom line, which is why it’s suddenly the darling of the startup world.

1. It Actually Feels Native (Because It Is)

Remember those cross-platform apps that felt a bit… off? Like a cover band trying to play a classic rock anthem, it’s close, but it’s not the real thing. That’s because those apps often tried to fake the native experience.  

KMP, on the other hand, doesn’t fake anything. It lets your developers use the actual, honest-to-goodness native UI tools (SwiftUI for the Apple crowd, Jetpack Compose for Android).  

This means your app scrolls like an iPhone app, animates like an Android app, and generally behaves exactly as users expect. There’s no awkward pause, no slightly janky animation. It’s the real deal, and your users will notice.

2. Maintenance Costs

Building an app is one thing; keeping it alive and bug-free for years is another.  

If you’ve built two separate apps, every bug fix, every new feature, every tiny tweak means doing the work twice. This inevitably leads to what we in the industry call “logic drift,” which is when your iOS app starts doing one thing and your Android app decides to do something slightly different.  

With KMP, your app’s logic is unified. Fix a bug in the shared logic, and it’s fixed everywhere.  

This isn’t just convenient; it’s a significant reduction in long-term costs, freeing up precious capital for things like, say, actual marketing instead of just fixing the same bug twice.

3. The Talent Pool

Hiring good developers is harder than finding a parking spot in Manhattan on a Saturday. If you’re using a niche framework, you’re essentially fishing in a very small pond.  

Kotlin, however, is the language of choice for Android development, and it’s gaining traction everywhere else. So, by going with KMP, you’re tapping into a vast ocean of talented developers.  

Plus, your iOS developers, who are probably quite fond of their Swift and SwiftUI, don’t have to abandon their craft. They can continue building beautiful UIs while happily consuming the shared Kotlin logic. It’s a win-win.

4. Future-Proofing Your Investment

One of the scariest phrases in tech is “framework lock-in.” It’s when your entire business is built on a technology that could, theoretically, disappear or become obsolete overnight.

KMP, being built on Kotlin (a language backed by serious players like JetBrains and Google), offers a much safer bet.  

It’s also modular. You don’t have to go all-in from day one. You can start by sharing just a tiny piece of logic—say, your login screen—and then gradually expand.  

This low-risk, high-reward approach is perfect for founders who understand that agility is not just a buzzword, but a survival strategy.

When it comes to choosing how to build your app, you’ve got options. It’s like picking a car: they all get you from A to B, but some do it with more style, some with more efficiency, and some will leave you stranded on the side of the road wondering what went wrong.  

Here’s a quick, no-nonsense comparison:

Kotlin Multiplatform

• Time to first version: Surprisingly quick, especially with Compose

• App performance: As good as it gets

• UI customisation: You want it. You got it.

• Long-term viability: Excellent

• Hiring developers: Easy (Kotlin/Swift)

Flutter

• Time to first version: Blazingly fast

• App performance: Very good

• UI customisation: Very flexible

• Long-term viability: Good, with Google’s backing

• Hiring developers: Requires learning Dart

React Native

• Time to first version: Pretty fast

• App performance: Can be sligguish with heavy UI or complex logic

• UI customisation: Decent

• Long-term viability: Moderate, depending on Facebook

• Hiring developers: Very easy

The true genius of KMP isn’t just sharing code; it’s sharing the complicated bits so your users get a seamless experience, and your bank account doesn’t weep.

If you’re thinking KMP sounds too good to be true, rest assured, real companies, with real money on the line, are using it to great effect.  

• Netflix: Yes, that Netflix. They’re using KMP to manage the complex logic behind their internal production tools. This means that whether their producers are on an iPhone, an Android tablet, or a web browser, the underlying scheduling and resource management works flawlessly. Nobody wants to mess with Netflix’s production schedule.

• Cash App: When you’re dealing with people’s money, “good enough” isn’t good enough. With KMP, Cash App can innovate faster while maintaining the ironclad reliability and security that financial applications demand.  

• McDonald’s: From Tokyo to Timbuktu, McDonald’s adopted KMP to share the core ordering and loyalty logic across their global mobile apps. This ensures that whether you’re ordering a Big Mac in New York or a McFlurry in Paris, the experience is consistent and reliable.

Before you dive headfirst into any new technology, it’s always wise to pause and ask a few pointed questions:

1. Do you care about performance?

If your app needs to be buttery smooth, lightning-fast, and deeply integrated with device features (think complex animations, heavy data crunching, or talking to obscure hardware), then KMP is probably your best bet. If you’re building a glorified to-do list, maybe not so much.

2. Do you have (or plan to have) native developers on your team?

KMP shines when you have developers who appreciate the native experience but want to work more efficiently. It’s not about replacing your native teams; it’s about making them exceptionally effective.

3. Are you building a product for the long haul?

If this is a quick, throwaway prototype, then a simpler, faster framework might get you to market quicker. But if you’re laying the foundation for a multi-year business, KMP’s inherent scalability and stability will save you headaches (and money) down the line.

4. Do you dream of expanding beyond just mobile?

KMP isn’t just for phones. It can target web, desktop, and even servers. If your grand vision involves a seamless experience across all these platforms, KMP gives you a powerful head start.

KMP is fantastic, but it’s not a magic wand you wave to instantly create a perfect app.

Implementing it correctly requires a deep understanding of the Kotlin ecosystem and a healthy respect for the quirks of both iOS and Android.  

For many founders, trying to figure all this out while also running a business is like trying to juggle flaming torches while riding a unicycle on a tightrope. It’s possible, but generally not recommended.

This is where a specialised Kotlin development agency, one that truly understands KMP, becomes less of an expense and more of a strategic advantage. Here’s how we help you avoid pitfalls:

1. We Build Foundations, Not Just Features

The biggest trap with any new technology is poor planning.  

If your shared code isn’t structured correctly from the get-go, you’ll end up with a tangled mess that’s hard to test and maintain.  

Octogle (that’s us) brings battle-tested architectural principles to the table, ensuring your shared logic is robust, scalable, and won’t give future developers any problems.  

2. We Speak Both Kotlin and iOS (Fluently)

While KMP makes sharing code easier, there are still nuances when integrating Kotlin into an iOS project. Things like handling concurrent operations (Coroutines) or managing memory can be tricky.  

Our team has spent years in the trenches, mastering these “interop” challenges. We know how to make that shared Kotlin code feel like it was born and raised on an iPhone, ensuring your Apple users never feel like they’re using a non-native app.

3. We Help You Choose Your Level of Sharing

One of KMP’s strengths is its flexibility. You can share just the logic, or you can go all-in and share the UI with Compose Multiplatform. The right choice depends on your specific goals, budget, and timeline.  

We provide the strategic guidance to help you make that decision, ensuring you get to market faster without compromising on quality. It’s about finding the sweet spot between speed and perfection.

4. We Save You from the “Hidden Costs” of Inexperience

Beware of the “generalist” agency that claims to do everything. They might say they can handle KMP, but if they’re learning on your dime, you’re accumulating technical debt faster than a politician accumulates promises.  

By partnering with KMP developers for hire, you’re investing in expertise that prevents costly mistakes down the line. We don’t just deliver code; we deliver peace of mind and a product that’s meant to increase the value of your company.

The tech landscape is always shifting, often with the grace of a runaway freight train.  

At Octogle, we specialise in helping founders like you navigate the complexities of modern app development, leveraging the power of Kotlin Multiplatform to turn your ambitious ideas into high-performance digital products.

Whether you’re sketching out your first MVP on a napkin or looking to untangle an existing codebase, we’re here to help. Our process is transparent, collaborative, and obsessively focused on one thing: your return on investment.

So let’s chat about your project.