Architecture that understands mobile: Why the backend must catch up

The best mobile apps are not just shiny or visually pleasing; they’re fast. Not in a theoretical-lab-speed kind of way, but fast and functional in the real world where you encounter patchy networks or older devices. 

The biggest barrier to this is often the backend and integrations, because no matter how elegant your interface or how smart your user journeys, if your backend, middleware or integrations aren’t built for mobile, user experience will suffer. 

The unseen bottleneck

A common issue that we see, but remains unseen to many non-specialist teams, is that most mobile experiences are powered by APIs designed for desktop or web platforms. They weren’t built to handle the constraints of a 4G connection on a moving train, or to respond quickly enough when your user flicks between screens mid-task. Chatty systems which have to operate on a high latency network can kill the user experience whilst dealing with network outages and slow downs can also create friction with users

That mismatch can turn even the most beautifully designed app into something that feels sluggish, unresponsive, or unreliable - ultimately, damaging that all important trust with your customer.

When the backend doesn’t understand the needs of mobile, it becomes a bottleneck, throttling performance before the interface even has a chance to shine.

The cost of this bottleneck

The cost of this mismatch can equate to huge losses for large organisations - here’s some food for thought:

• If an app takes more than 3 seconds to load, 53% of users will abandon it

• A 1-second delay in load time can reduce conversion rates by up to 7%

• Nearly half of users uninstall or stop using apps if performance is sluggish, crash rates are high, or responsiveness is poor

We all know that abandoned journeys, reduced conversion rates and high uninstalls damages revenue, and for big brands, this can mean millions lost annually. This really highlights the importance of ensuring that the backend catches up.

Why Backend-for-Frontend helps you to avoid these costly mistakes

This is where Backend-for-Frontend (BFF) architecture can come in to reduce bottlenecks and improve performance.

A BFF layer gives your mobile app its own tailored backend experience. It understands the specific payloads, caching, and session management mobile requires. It bridges the potentially problematic gap between your mobile experience and your wider platform, optimising every call and response for the realities of mobile use.

It’s the difference between sending everything and sending what’s needed, between waiting and acting instantly.

The real impact of mobile-specific BFF

We saw this first-hand with a major high-street retailer whose app performance was dragging. On paper, everything looked fine; they had a solid infrastructure, good APIs, and a slick, modern design. But in practice, the mobile experience lagged, it didn’t perform as customers expected, and it experienced drop-offs, abandoned baskets and uninstalls.

The culprit? Backend systems that weren’t mobile-aware.

By introducing a mobile-specific BFF layer, we cut payload sizes by 70% and improved load times by more than three seconds. That shift made their whole mobile experience feel smoother, faster and frictionless; experiences that customers remember and value. 

Mobile-first = backend-first

The lesson here is simple: if your backend doesn’t think mobile-first, your app will struggle to perform at its best.

It’s easy to obsess over slick visuals and a fancy front-end. Whilst these do also matter, true mobile excellence comes from the architecture supporting the experience beneath the surface.

At Apadmi, we know that optimised mobile experiences come from every layer working together: Product and UX are an important part of this, but considering architectures, backends, session management, caching, and error tolerance is also key. When the backend catches up, real value can be unlocked. 

This is why 15 years ago, we added backend and integration mobile experts to our team.  Nearly half of our tech team are backend and integration engineers and true specialists in building systems and integrations optimised for mobile experience.

I would love to explore this further with you, and understand how your backend might be holding you back - if you would like to come to one of our tech events or just grab a coffee, get in touch.