Software that works for you again
Stuck with legacy software that feels risky and expensive to change?
Our clients come to us with the same story: a business-critical legacy web application has become too fragile to change, but too important to leave alone. Maybe the original developer vanished. Maybe the tech debt compounded until every release became a gamble. Either way, the application that once drove the business now holds it back.
We've transformed platforms processing over £100M in transactions, driven 192% increases in feature velocity, and brought codebases back from the brink when nobody else would touch them. Our legacy system modernisation approach follows 4 clear steps — assess, stabilise, modernise and support. The result is software you're back in control of.
We’re trusted by some
great UK businesses:
What aging software is really costing your business
The Terrifying Cost of Legacy Applications.
When maintenance and modernisation on legacy software is deferred, costs begin to mount in unexpected ways.
Businesses spend 60–80% of their IT budgets keeping legacy systems going. Not building. Not improving. Just keeping the lights on.
The real costs go far beyond this. If your web application breaks down regularly, or has errors that keep resurfacing, you’re losing revenue and customer trust with every incident. We’ve seen businesses bleed tens of thousands per month from issues related to their legacy systems.
Then there’s the slowing of feature velocity. When every change takes weeks instead of days, competitors who ship faster will overtake you. This is what technical debt does: the cost of shortcuts accumulates until making any change becomes so expensive it yields no return on investment. It’s just like compound interest working against you.
Your legacy application will struggle to talk to the tools your business now depends on, too. Modern payment processors, CRM platforms and marketing automation will become unavailable to you, and you’ll be stuck running parallel systems and complex workarounds. That’s wasted time and wasted money, and it only gets worse with time and growth.
Another commonly overlooked problem resulting from legacy software is staff turnover. Your employees don’t want to work on slow, fragile, and unreliable systems to get their jobs done. They want tools that enable them to do their best work. If you’re struggling to hire, train and retain technical staff, your legacy systems could be a major contributing factor.
Security is another risk you absolutely cannot afford to ignore. Aging system dependencies carry known vulnerabilities, and if your application handles personal data, GDPR compliance isn’t something you can just put off. A breach doesn’t just cost you in fines. It costs you customers who will never come back. Legacy application modernisation addresses these risks before regulators or attackers force your hand.
All of this adds up. Lost revenue, lost time, lost customers, lost talent. The longer legacy software modernisation is deferred, the higher the bill grows. The good news is you don’t have to live with this. Read our legacy system modernisation guide to get a better understanding of what’s involved in getting back on the right track.
What is legacy system modernisation?
What Is Legacy System Modernisation?.
It's not about starting over — it's about making what you have work harder, last longer, and grow with your business.
Legacy system modernisation is the process of updating outdated software applications so they meet current business needs.
Rather than replacing an entire system from scratch, modernisation means continual improvement — upgrading frameworks, restructuring code, improving performance, and adding modern capabilities. All while keeping the application running and serving the business throughout.
It’s critically important to SMEs with legacy software applications, because it avoids the potentially catastrophic scenario of wasting vast sums of money on a rewrite that never goes live, or doesn’t adequately address the issues with the legacy system it was meant to replace.
Instead, modernisation ensures investment is made incrementally — addressing the issues with the legacy system and delivering value continuously in a risk free way. It also has the added benefit of teaching businesses how to develop their software balancing maintenance and new features going forwards, which is critical for long-term growth.
Our full guide - What is legacy system modernisation?
Has been invaluable
“BitBrawn have not only performed exceptionally well on two projects for me, but stepped in to help when an issue arose with a former developer. Without assistance they methodically unravelled older web applications in order to understand their structure and setup. Their assistance has been invaluable.”
This service is built for a specific type of business
We Work With Specific Businesses and Technologies.
Our ideal client is a small or medium sized enterprise with an aging Ruby or JavaScript application that’s causing them pain.
We’re perfect for you if…
- You’re a small or medium sized enterprise (SME), or you have a high degree of agency within a larger organisation.
- You have a Ruby or JavaScript based software system that’s become slow, fragile or otherwise expensive to maintain.
- Your original developer or agency has moved on, and nobody wants to touch the system.
- You want to improve your application while keeping it running, and without starting from scratch.
- You want to work closely with adept senior specialists, rather than a non-technical project manager and their team.
Whether your application runs on Rails or React, Express or Next.js, we've worked with the full spectrum of Ruby and JavaScript ecosystems. Our focus means we can step into unfamiliar codebases and deliver improvements with confidence.
We’re not the right fit if…
- You’re the kind of organisation where every small change requires layers of sign-off and coordination meetings.
- The legacy application you’d like to modernise is not primarily JavaScript or Ruby based.
- You want to replace your legacy system with a brand new application built from scratch rather than modernisation.
- You’re just looking for an extra pair of hands to supplement your development team rather than true modernisation expertise.
- You’re not comfortable with working with a business operating in a UK time zone.
We've chosen to work with the kinds of businesses we’re able to deliver great results for. If nothing above causes you concern, then we should be able to achieve brilliant results for you modernising your legacy system.
How we modernise your application — four clear phases
Our legacy system modernisation process follows four distinct phases in a natural progression, designed to deliver value at every step with room to adjust as we learn more about your application.
Assessment
Understand what you have and what's holding you back.
We audit your codebase, infrastructure, and business goals. You get a jargon-free report explaining what's wrong, what's working, and what to prioritise.
The assessment is a standalone engagement — there's no commitment to proceed. But if you do, you'll have a clear, prioritised roadmap to work from.
Stabilisation
Stop the bleeding, and get control over your system.
We fix the critical issues first: security vulnerabilities, performance bottlenecks, failing tests. This is the fastest part of legacy software modernisation — and the most important.
Once it's done, you're back in control. Your team can deploy with confidence, and your users stop hitting the problems that erode trust.
Modernisation
Incremental phased improvement. Not risky big-bang rewrites.
Using the strangler fig approach — gradually replacing old code with new, one piece at a time, so the application never goes offline — we upgrade frameworks, refactor the problem areas, and add capabilities.
Every change is deployed as a small, tested milestone. No big-bang releases, no downtime. This is how legacy application modernisation should work.
Ongoing Support
We’re here as long as you need us.
Our work comes with 30 days of complimentary support and bug fixes. If something isn't right, we'll sort it — no questions asked.
After that, we offer ongoing options for performance monitoring, incremental improvements, and future feature development. We're there when you need us.
Results from real modernisation projects
The Results Speak for Themselves.
Just a few of the numerous legacy application modernisation projects we’ve been a part of. Real clients demonstrating real transformation.
192% more claim submissions
RIFT’s tax refund platform hadn’t kept up. Outdated Rails, fragile codebase, customer data duplicated. We stabilised the foundations, rebuilt the self-service experience, and unified their data into a single API.
The result? Claim submissions up 192%, unique sign-ins up 84%, and data accuracy on essential claim information submitted by their customers of above 99%.
”Understand the business issues we’re trying to solve and develop practical solutions”
£100M marketplace modernised
We helped build Laced’s sneaker marketplace in 2018. £100M+ in sales later, the single-market system couldn’t support European expansion. So we helped to rework the foundations without downtime.
Laced now ships globally and has full-site translation and localisation for multiple countries. Adding more is a configuration exercise, not an engineering project.
”Significantly reduced both our time and costs across multiple intricate projects”
Urgent rescue, ongoing partnership
Allocate’s lead developer vanished. No documentation, no handover. Just dozens of Node.js and React services that nobody understood, where fixing one bug broke something else.
We mapped the system, fixed the critical bugs hitting bookings and payments, and got deploys working safely again. That emergency rescue turned into an ongoing partnership; we’re still there.
”Without assistance they methodically unravelled older web applications.”
Common questions about legacy system modernisation
Frequently Asked Questions.
Some of the common questions we get about rescuing and modernising aging web applications from customers.
How much does legacy system modernisation cost?
It depends on the state of your codebase and what needs doing, but most projects land between £10,000 and £50,000. We'll give you an honest estimate after an initial assessment.
How long does it take?
Stabilisation typically takes 4–8 weeks; full modernisation can run 3–6 months depending on scope. We break everything into milestones so you see progress and value throughout.
Should I rewrite or refactor my legacy app?
Almost always refactor. Rewrites sound tempting but they're expensive, risky, and take far longer than anyone expects. Incremental improvement gets you there without betting the business on it.
What are the signs my web app needs modernising?
If changes take forever, bugs keep appearing in unexpected places, or your team is afraid to touch certain parts of the codebase — it's time. Security warnings you can't address are another red flag.
What is the Strangler Pattern?
It's a technique for replacing legacy systems piece by piece rather than all at once. You build new functionality alongside the old, gradually routing traffic to the new code until the legacy parts can be safely removed.
What’s included in the free consultation call?
We’ll do a couple of quick intros, ask you some questions to figure out how best we can help you, and give you an opportunity to ask any questions you have of us.
Will my application go offline during modernisation?
We deploy changes incrementally and use blue-green deployments where appropriate. Your users shouldn't notice anything except that things start working better.
Can you modernise a system built by another agency?
Absolutely. We only require that the other agency is either not working on the system, or is willing to agree to give us complete autonomy to do our modernisation work.
What’s the difference between modernisation and digital transformation?
Modernisation is about improving one or more software systems. Digital transformation is about replacing human systems with software. Legacy system modernisation may be a key part of a digital transformation strategy, though.
Can you charge a fixed price?
Yes. We prefer to charge a fixed price for project milestones, because our clients prefer certainty. We usually invoice on a 50% up-front, 50% prior to go-live basis.
Do you offer support?
Our work comes with 30 days of complimentary bug fixes and support from the point it goes live. Outside of this, support can be negotiated on a per-engagement basis.
What if our plans change?
Our milestone-based approach means we can adjust the scope of the project as needed. We can negotiate something new or cancel milestones. Cancellations will mean no deliverables from us, and no 50% final payment for you.
Will you come to our offices?
Yes — We primarily work remotely, but we're happy to be with you in-person when it makes sense to do so. This can be factored into the scope of your project, or billed for at an hourly rate.
Are you the right size for us?
Where necessary, we can pull in additional resource from a network of trusted associates (skilled designers, developers, and subject matter experts) to keep things running smoothly.
What if our codebase is a mess?
This is our speciality. We've inherited plenty of undocumented, fragile codebases. We'll assess what you have and give you an honest picture of the work required.
Do we need a full rebuild?
Usually not. We modernise incrementally, addressing the worst problems first while preserving what works. Full rebuilds are rarely necessary.
What if our previous developer disappeared?
This is common. Our assessment process is designed for exactly this situation. We'll document what exists and get you back in control.
Contact
Ready to get back on track?.
Book a free consultation call to discuss your aging JavaScript or Ruby application, or email us directly.
Book a consultation call
We offer a free 15 minute call to discuss rescuing your aging application, so you can ask questions while getting to know us.
Book a consultationEmail us
If you have any questions, want to send us a message, or simply prefer communicating digitally, you're more than welcome to email us instead.
hello@bitbrawn.com