The development of banking apps was supposed to provide users with convenience, control and piece of mind. However, for thousands of Halifax customers recently, a major mobile outage caused the exact opposite, leaving customers unable to check balances, or pay bills, sparking widespread frustration.

This wasn't an isolated incident. In the first four months of 2025 alone, major high-street banks including Lloyds, TSB, Bank of Scotland, Nationwide and First Direct all experienced outages. When only 23% of Brits trust financial apps, the number is unlikely to improve if banking services remain vulnerable during critical moments.

The reality is mobile banking has become a core part of daily life. For many people, it's their primary way of managing money. Data shows that 37% of UK residents check their current account balance daily so repeated failures only weaken trust in apps.

So why are these failures still happening?

The short answer is that many banks are still relying on legacy systems that weren't built for the complexity of today's digital world and they're being pushed to their limits. These platforms must now support diverse devices, operating systems, third-party integrations, and cloud services. But without modern delivery practices, even routine updates can become high-risk deployments.

To prevent future outages and build more dependable digital services, banks need to rethink how they deliver and manage change. DevOps offers a practical framework for doing just that. There are four strategies that can help banks modernize their delivery approach and minimize disruption:

1. Start small, then scale

Rather than deploying a new feature or update to all users at once, changes are rolled out in controlled stages, starting with a small percentage and expanding only when stability is confirmed, and no further issues are detected. This is especially important for banks as with a staged approach they can check potential impacts before it hits the entire customer base.

2. Keep watch in real time

Teams need a clear view of the issue before they can respond and effectively address. Continuous monitoring and observability allow DevOps teams to detect abnormal system behavior immediately. When something does go wrong, automated rollback allows a fast return to the last known good state, minimizing user impact and preserving trust.

3. Stay agile under pressure

Not every problem needs a new build. Feature flags and runtime controls empower teams to make live adjustments without a full redeployment. That means if something breaks, it can be toggled off instantly, without bringing the app down for everyone.

4. Tailor updates to your audience

Customers use different devices and platforms, so why push identical updates to everyone?

Instead of pushing updates universally, banks can target specific groups to minimize disruption and gain clearer insights into performance across different environments.

Building Resilience Starts with Modern Delivery Practices

The Halifax outage may not be the last, but it should serve as a turning point for the industry. It highlights a clear urgent need for banks to rethink how they build and maintain the systems millions rely on daily. Legacy approaches to software delivery simply can't keep pace with modern demand, and they're putting customer trust at risk.

To meet the expectations of today's users, banks need the ability to move quickly, resolve issues in real time, and deploy changes safely. DevOps provides the mindset, practices and technology to make that possible, helping institutions avoid widespread disruption while continuously improving the customer experience.

Reliability is everything. Adopting DevOps isn't just about preventing the next outage. It's about building the foundations for a more agile, trustworthy, and future-ready banking sector.