Top Application Modernisation Challenges and Solutions

Everything is becoming modern, from the phones in our pockets to the way we order a takeaway. So, it is no surprise that businesses across the UK are feeling the push to modernise their old software and systems too.

However, here lies the problem: modernising applications isn’t as easy as it sounds and definitely not like flipping a switch.

Many organisations have been running their apps for years, making legacy applications essential for daily functioning. These systems may be outdated, slow, or difficult to maintain, but they still get the job done.

Thus, the main thing is how to transition from these old setups to faster, more flexible, cloud-friendly systems without risking all your setups being destroyed.

UK businesses are facing some serious roadblocks when it comes to application modernisation. With challenges in application modernisation, the process of changing systems and making them more modern can be a struggle. One wrong turn could delay operations, increase costs, or frustrate your entire team.

This blog will help you become aware of the top application modernisation challenges that UK businesses are dealing with, along with the solutions on how you can tackle these challenges.

What is Application Modernisation?

As the name suggests, application modernisation is updating old software that matches the new business needs, tech trends, and users’ needs.

Many businesses still use legacy systems, which are older applications that may have worked perfectly in the past but are now slow, difficult to update, or don’t play well with the latest tools like cloud services or mobile apps.

Modernising these apps helps companies reduce costs and deliver better services to their customers.

There are different ways to modernise an application. You can:

🔘Move it to the cloud (called rehosting)

🔘Tweak and improve the existing code (refactoring)

🔘Completely rebuild it from the ground up using the latest programming languages and frameworks.

Application modernisation is a way of changing or updating your application to ensure you don’t fall behind your competitors because nothing stays the same, whether it is your business needs or your users' demands and expectations.

When Do the Companies Decide to Modernise Their Apps?

There are many reasons why companies decide to modernise their apps, especially when they start to face problems with their current systems. Here are some signs of why they modernise their apps.

🔘If apps are slow, crash often, or can’t handle more users.

🔘Older systems often need frequent patching and support, which drains money and time.

🔘When they want to solve security issues because legacy apps can be a target for data breaches as they don’t meet the current cybersecurity standards.

🔘When new software, tools, or platforms can’t work with the old system.

🔘Businesses that want to go cloud-first, offer mobile solutions, or scale quickly often find their legacy apps aren’t up to the task.

🔘If the provider no longer supports the software or hardware a company uses, then businesses decide to modernise their apps.

Other reasons include improving the product’s reliability, increasing competitive advantage, reducing costs, improving user experience, dealing with system complexities, stopping the usage of outdated development tools, improving code maintainability, and many more.

In short, when the risks of staying the same start to outweigh the effort of change, companies realise that it is time to modernise.

What Benefits Does Application Modernisation Offer to UK Businesses?

Before we get into the application modernisation challenges, let’s learn the benefits UK businesses experience after modernising their apps.

1. Improved Performance and Speed

Modern applications are faster and more responsive. When a business decides to modernise its legacy systems, it often sees results like faster loading times.

Plus, there are generally fewer crashes and a better ability to handle large volumes of data. It improves customer and employee experience. Modernisation enhances performance, which allows applications to handle growing workloads.

2. Lower Operating and Maintenance Costs

It is often more expensive to keep running the old systems. However, modernised applications, especially those running in the cloud, require less manual upkeep. You also save money by reducing downtime and avoiding costly fixes when your old software breaks unexpectedly.

3. Enhanced Security and Compliance

A legacy application is always at risk of security vulnerabilities. That is because they lack the updates and latest security features to keep the data safe.

Modernisation implements various security policies and has tools like encryption, access controls, and regular updates to fix any security issues, which helps businesses protect their customers' information.

4. Greater Business Agility

These applications are flexible, which means your business can react quickly to shifts in market trends, the launch of a new service, or a shift to remote work. With the right tools, you can add new features or make adjustments in a few days.

5. Better Customer Experience

Customers usually have higher expectations. They want a smooth digital experience, whether they are booking a service, shopping for something online, or just going through your website. An outdated app may not meet these expectations. However, modernised apps can offer:

🔘Personalised experiences

🔘Quick checkout or booking

🔘Easy navigation

🔘Excellent mobile support

This can increase customer satisfaction, loyalty, and sales.

6. Scalability

Scalability limits can often be seen in legacy applications. Businesses usually want their app to be scalable, so that it can grow or improve with their business.

Modern apps are also scalable, allowing you to expand to new regions, manage more users, or offer new services. They also allow for future upgrades, so you won’t have to build everything again.

7. Support for Remote Work and Hybrid Teams

Cloud-based and modernised applications make it easy for teams to work from home, collaborate in real-time, and stay productive no matter where they are. This is a major advantage for UK companies adapting to hybrid work models.

Application Modernisation Challenges & Their Solutions

Modernising an application may sound exciting, but making changes in business often comes with some challenges.

For UK companies, especially those that have been running on the same systems for years, using the latest and modern tech can feel overwhelming. However, every challenge has a solution.

Below are some of the common application modernisation challenges and their solutions.

Challenge 1: Lack of Skilled Workforce

The first challenge UK businesses face when modernising their applications is finding people with the right skills.

Technologies like cloud computing, microservices, DevOps, and containers are all quite advanced, and not every developer is trained in them.

Many companies depend on IT professionals who are used to working with older systems, and switching to the latest tools requires a whole different skill set. This shortage of modern tech experts can slow down projects.

Solutions

🔘Upskill your current team through online training, courses, and certifications.

🔘Partner with experienced IT consultants or development agencies for temporary support.

🔘Encourage a culture of continuous learning within your tech teams.

🔘Start small by introducing new tools gradually to allow hands-on learning.

Challenge 2: High Cost of Modernisation

Modernising applications involves upgrading infrastructure, redesigning software, and sometimes hiring external experts, which can lead to higher costs.

This cost can feel too expensive for small and medium businesses, especially if they are unsure about the returns. Upfront investment can be significant, and it often competes with other business priorities.

Solutions

🔘Break the project into phases and start with critical systems first.

🔘Use cloud services with pay-as-you-go pricing to reduce upfront expenses.

🔘Apply for government grants or tech funding available in the UK.

🔘Regularly review ROI to justify spending and adjust where needed.

Challenge 3: Data Migration Complexities

Moving data from old systems to new ones is no easy task. Data stored in legacy apps can be outdated, incomplete, or have duplicates. Therefore, the bigger the company, the more complex this migration becomes.

If anything goes wrong during the transfer, it could lead to data loss, inconsistencies, or even legal issues, especially if personal customer information is involved.

Solutions

🔘Conduct a full audit of existing data before migration.

🔘Clean, organise, and remove duplicate or outdated data.

🔘Use trusted data migration tools to reduce errors.

🔘Test the migration with smaller datasets first and always keep a backup.

Challenge 4: Cultural Resistance to Change

Modernising technology is one thing, but changing people’s mindsets is another. That is why another one of the top application modernisation challenges is resistance to change.

Many employees, especially those who have worked with legacy systems for years, may feel nervous about switching to new tools.

They worry about job security, learning new software, or adapting to different workflows. This kind of resistance can slow down or derail modernisation projects.

Solutions

🔘Communicate the purpose and benefits of modernisation clearly to all staff.

🔘Involve employees in the decision-making process where possible.

🔘Provide proper training and ongoing support for new tools or processes.

🔘Address concerns directly and promote a positive mindset about change.

Challenge 5: Choosing the Right Tech Stack

There are so many different programming languages, frameworks, and cloud services out there today that it can feel overwhelming.

Picking the wrong one can lead to wasted time, money, and frustration. And because technology keeps changing, businesses worry that what they choose today might become outdated in a few years.

Solutions

🔘Align tech choices with current needs and business goals.

🔘Consult with experts or tech companies in the UK before making final decisions.

🔘Choose tools that are well-supported, flexible, and scalable.

🔘Run pilot projects to test new stacks before full implementation.

Challenge 6: Legacy Code and Infrastructure Dependencies

Legacy applications were developed using coding languages that were popular at the time they were built and depend on hardware that doesn’t support them anymore.

That is why making any changes to these systems can be risky and take a lot of your time. Even a small change might break something else unexpectedly, which can lead to major disruptions.

Solutions

🔘Slowly replace legacy parts using the "strangler pattern."

🔘Use tools to map and understand code dependencies.

🔘Keep legacy systems running in parallel during the transition.

🔘Modernise in layers, starting with the most essential functions.

Challenge 7: Security and Compliance Woes

Legacy systems often lack proper security features, making them vulnerable to attacks.

At the same time, keeping up with rules like the UK’s Data Protection Act and GDPR can be difficult if your systems aren’t up to date. A security breach or non-compliance fine can be a huge blow to any business.

Solutions

🔘Perform a security audit before beginning modernisation.

🔘Use cloud development platforms with features like encryption and access control.

🔘Adopt DevSecOps practices to include security in each development step.

🔘Keep legal and compliance teams involved throughout the project.

Challenge 8: Vendor Lock-In Risks

Vendor lock-in risks is also the application modernisation challenges faced by many businesses. If businesses depend too much on one software vendor or cloud provider, they can limit their options later.

If the vendor changes pricing, drops support, or becomes unreliable, you could be stuck with a costly and painful transition.

Solutions

🔘Use open-source or widely adopted technologies when possible.

🔘Avoid building systems that are too tightly tied to one vendor’s tools.

🔘Use APIs, containers, and other flexible solutions to make your app more portable.

🔘Consider multi-cloud or hybrid-cloud setups to reduce dependency on just one provider.

Challenge 9: Integration with Other Systems

Modern apps still need to work alongside existing systems like CRMs, ERPs, or third-party platforms. Making all these systems "talk" to each other can be challenging, especially if they weren’t designed with integration in mind.

Solutions

🔘Use APIs and middleware for smooth connections between systems.

🔘Document how systems interact to prevent integration gaps.

🔘Move toward microservices or modular architecture.

🔘Test each integration thoroughly before going live.

Challenge 10: Measuring the Success of Modernisation

After putting in so much time and money, how do you know if modernisation is really working? Without proper goals and measurement, it is hard to tell what’s improved.

Solutions

🔘Set clear goals before the project starts.

🔘Track metrics like speed, uptime, user feedback, and support tickets.

🔘Use analytics tools to monitor performance and improvements.

🔘Review progress regularly and adapt the strategy as needed.

Challenge 11: Project Delays and Scope Creep

It is easy for modernisation projects to grow beyond their original plans. This is what we call scope creep, where a project keeps expanding without proper control.

New features get added, priorities shift, and deadlines get pushed back. This becomes challenging because it not only delays results but also increases costs.

Solutions

🔘Use Agile project management to break work into small tasks.

🔘Set fixed goals and clear deadlines from the start.

🔘Review progress frequently with the team and stakeholders.

🔘Avoid adding new features in the middle of the project unless necessary.

Challenge 12: Business Continuity Risks

During application modernisation, there’s always a risk that something will go wrong and interrupt your business workflow.

What if the app crashes in the middle of the day? What if important data is lost or users can’t access the service? Even a few hours of downtime can lead to lost sales and unhappy customers.

Solutions

🔘Always keep backups and a rollback plan.

🔘Use phased rollouts to update one part of the system at a time.

🔘Test everything in a staging environment before launching updates.

🔘Use blue-green deployment strategies to switch from old to new systems.

Challenge 13: Budget Constraints

Especially for small and startup businesses, finding the money to modernise can be a challenge. It may feel like a luxury instead of a necessity, even though legacy systems often cost more to maintain in the long run.

There are also hidden costs, like:

🔘Hiring skilled developers

🔘Training staff

🔘Testing the system

🔘Fixing issues that can occur in the system.

Many companies begin with high hopes, only to find out in the middle of the project that they have no funds or that the project costs them more than they expected. This can result in them taking shortcuts or stopping the project altogether.

Solutions

🔘Focus on updates that give quick results.

🔘Use cloud services with flexible pricing to control costs.

🔘Apply for local tech grants or funding assistance.

🔘Treat modernisation as a long-term plan.

Challenge 14: Scaling Challenges Post-Modernisation

Even after modernising, some businesses struggle with performance as demand grows. The system may have been updated, but it wasn’t built to be scalable. This means that the system may not handle more users, data, or features as the business grows.

Solutions

🔘Use cloud infrastructure with auto-scaling features.

🔘Design systems that can handle growing user demand.

🔘Monitor usage regularly and optimise resources accordingly.

🔘Conduct load testing to ensure systems stay responsive during busy times.

Effective Strategies to Approach Application Modernisation Challenges

Many challenges can occur when adopting application modernisation. You can avoid them by implementing effective solutions.

However, using the right and strategic approach can also somewhat mitigate potential challenges. Here are the strategies you can use to approach application modernisation challenges.

1. Start with a Clear Plan and Vision

Let’s come directly to the point! You should know why you want to modernise your application and what results you hope to achieve.

If you have a clear goal, you will know where you need to focus, which will help you avoid distractions. You can write down your plan, list the features that you want, and get everyone on the same page.

This will act as a guide for you, which will allow you to make good decisions and avoid delays or wasted effort.

2. Involve Everyone from the Start

Modernising an application is not just an IT thing. It also impacts how teams work, how customers interact, and how the data is managed. That is why it is important to bring everyone on board early.

You can talk to your staff, get input from different departments, listen to their concerns, and keep them updated. When people feel included, they become ready to support the change.

Also, their input helps identify problems or opportunities you may not have noticed.

3. Choose the Right Tools and Technologies

The next approach to application modernisation challenges is to opt for tools and technologies that meet your needs.

However, you should do your research and choose platforms that match your goals and your team’s skills.

If needed, talk to tech experts or consultants who can guide you. Don’t just pick what’s trendy now; choose what will still work years from now.

4. Prepare and Train Your Team

One of the most common problems in modernisation is that the staff isn’t ready to use or manage the updated systems.

New development tools mean new skills. Your team needs time and support to get used to the updated systems. Offer training sessions, bring in coaches, or use online courses to help them learn.

Encourage your team to ask questions and experiment with the new system. The more confident your team feels, the more comfortable and smooth the transition will become for them.

5. Modernise in Phases, Not All at Once

You can’t change everything at once because the process can be risky and cost you more. Instead, you should break the work into smaller parts, which is quite similar to Agile development methodology. Maybe start with one module or department.

Test it, get feedback, and then move to the next. This phased approach reduces risk and gives you the chance to learn and improve as you go. Plus, it’s easier to handle within tight budgets and timelines.

Also Read: Top 15 Agile Development Challenges Faced by UK Tech Teams in 2025

6. Test Early and Test Often

You don’t need to wait till the project is completed to start testing. You can start before its completion and keep testing throughout the process.

This will help you catch bugs, spot weak points, and make improvements before they turn into big and significant problems. Try it out in different environments, on different devices, and with different users.

Get feedback, make changes, and keep testing until you are confident everything works as it should.

7. Always Have a Backup Plan

One thing you never want to happen during modernisation is losing important data or crashing your system. That’s why backups are so important.

Before making any big changes, make sure to back everything up. If something goes wrong during modernisation, a strong backup and recovery plan will save the day.

Ensure your team knows what to do in an emergency and how to quickly get systems back online.

8. Monitoring and Optimisation

Use tools to track performance and factors like loading times, error rates, and user behaviour. This data helps you make improvements.

Small changes can help you gain great results, especially when it comes to speed, stability, and user satisfaction. Keep checking key metrics and KPL to identify problematic areas for enhancement.

Wrapping Up

The technology, marketing trends, and customer demands keep changing so quickly that application modernisation is becoming necessary for businesses that want to explore new opportunities and create the best user experience.

Application modernisation is important for businesses that want to grow and keep up with technological changes. However, it doesn’t come without problems. Many companies face issues like outdated systems, high costs, a lack of skilled talent, and trouble moving data.

These are common application modernisation challenges, and almost every business faces them when modernising its apps.

The good thing is that with proper planning, the right support, and great efforts, these problems can be solved.

Are you looking for the best company that can modernise your application in the UK? Let Arramton Infotech take care of it for you.

We make things simple, clear, and right for your business. From planning to delivery, we ensure excellent results. You can also reach out to us if you want to start fresh with a brand-new application.

Frequently Asked Questions

Q1 What are the risks of not modernising legacy systems?

Ans If businesses don’t modernise, they risk falling behind competitors. Older systems can break down more often, be incompatible with newer tech, and are harder (and more expensive) to support. They can also lead to poor customer experiences and may not meet today’s data protection and compliance standards.

Q2 How long does it usually take to modernise an application?

Ans The time it will take to modernise an application depends on the size and complexity of the system. Some small updates can be done in weeks, while big ones may take months or over a year. Planning, testing, and gradual rollout are key steps that take time, but rushing the process can cause problems down the line.

Q3 How can a business prepare for application modernisation?

Ans Businesses can prepare for application modernisation by first understanding their current system, like what is working, what is not, and where the main pain points are. Involve IT, business teams, and decision-makers from the start. Set a clear goal, budget, and timeline.

Q4 Is cloud migration always part of app modernisation?

Ans Not necessarily, but it is common. Many modernisation strategies involve moving applications to the cloud for scalability, flexibility, and cost savings. However, some modernisation efforts focus mainly on improving performance, user experience, or maintainability without changing the hosting environment.

Q5 What’s the safest way to modernise legacy apps without downtime?

Ans A parallel-run strategy is one of the safest ways to modernise legacy apps without downtime. This means running both the legacy and modernised systems simultaneously while testing and validating each function. Gradual migration of users and data, combined with rollback plans and continuous monitoring, helps reduce risks and maintain business continuity.