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App Migration to Cloud, Done Right

Myth Digital is a cloud app migration company in Belfast and London. Our senior in-house team establishes a cost baseline, maps dependencies, benchmarks performance and produces a compliance checklist before any code is touched, so you get a clear, phased migration plan that cuts running costs and unlocks scalability.

  • Cost and dependency baseline
  • Performance benchmark included
  • Compliance checklist first
Book a discovery callHow we work
100% Senior in-house UK team
Global Clients range from start-ups to global
300+ Projects delivered to market
Myth Digital team at work in the studio and modernised interface elements

App migration to cloud means moving your existing software off legacy infrastructure and onto a platform that scales, costs less to run and doesn't hold your roadmap hostage.

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There are three broad approaches. Rehosting lifts your app to the cloud with minimal changes, giving you the fastest route but limited long-term gains. Replatforming swaps out specific components, such as databases or hosting layers, to unlock better performance without a full rebuild. Re-architecting redesigns the application for the cloud from the ground up. It delivers the most flexibility and scalability but requires more time upfront.

Each approach trades speed against future value. The right choice depends on your app's complexity, compliance needs and growth plans. That's why we start every migration with a focused discovery phase that maps dependencies, benchmarks current performance and surfaces risks before a single line of code moves.

AlphaVictor
Bushmills
Coca-Cola
Complieye
Elecsys
Glen Dimplex
LifePass
The Lir
NHS
The North Face
Perks
Queen's University
Deep RiverRock
SPAR

What do we bring to your cloud migration?

  • Audit

    Legacy Application Audit

    We map every dependency, flag technical debt and identify compliance gaps. You get a clear picture of what needs to move and what needs fixing first.

  • Design

    Cloud Architecture Design

    We design a target environment shaped around your performance needs and budget. No over-provisioned infrastructure, just a right-sized setup built to scale.

  • Delivery

    Phased Migration Delivery

    We migrate in defined milestones with rollback plans at every stage. You sign off progress as we go, so there's no big-bang risk.

Phone in jeans pocket showing a compliance app home screen

Discovery First, Then Commit

We run a focused discovery over the first two to four weeks. Our senior team audits your existing app, maps every dependency, benchmarks running costs and flags compliance or performance risks. You walk away with a clear migration plan and a go/no-go decision before any build work starts.

  • Cost baseline and performance report
  • Full dependency and integration map
  • Risk register with compliance flags
  • Recommended migration path forward

Which Migration Approach Fits You?

Every app is different. Your discovery outputs, including the dependency map, cost baseline and performance benchmarks, point to one of these approaches.

Rehost (Lift and Shift)
Meeting table with a whiteboard of notes

Rehost (Lift and Shift)

Best for teams that need to leave on-prem hardware fast without rewriting code.

  • Fastest route: typically weeks rather than months
  • Low risk because your application logic stays the same
  • Reduces hosting costs and removes hardware maintenance
  • Won't fix underlying performance or scalability limits
Replatform (Lift, Tinker and Shift)
Phone showing a meeting room with smart-device pins

Replatform (Lift, Tinker and Shift)

Right when your app mostly works but needs targeted improvements to run well in the cloud.

  • Swaps specific layers (database, caching, auth) for managed cloud services
  • Moderate timeline, longer than rehost but shorter than a full rebuild
  • Improves performance and reduces operational overhead
  • Requires careful dependency mapping from discovery
Re-architect (Refactor or Rebuild)
Team member standing at a whiteboard addressing the room

Re-architect (Refactor or Rebuild)

The right call when technical debt or a monolith architecture blocks growth.

  • Redesigns your app for cloud-native scalability from the ground up
  • Longest timeline but delivers the greatest long-term gains
  • Eliminates legacy constraints holding back new features
  • Higher upfront effort, justified when the business case supports it
Data Migration and Compliance
Phone in a pocket showing a building list app

Data Migration and Compliance

Data moves alongside your application. Getting this wrong open you to increaded risk of downtime, data loss or regulatory breaches.

  • We map every data source and integration during discovery
  • Migration is phased and validated at each stage, not a single cutover
  • GDPR and UK data residency requirements are built into the plan
  • We build and host on Microsoft Azure, which meets UK data-protection standards
Myth Digital team at work in the studio

Will there be downtime during migration?

The biggest concern we hear is downtime. Will customers lose access mid-migration? Our approach removes that risk. We run the new cloud environment alongside your existing system, route a small percentage of traffic to it first and validate everything before shifting the rest. If anything looks off, we can roll back instantly.

Each phase has a clear milestone and sign-off point. You know exactly what's going live and when. No surprises, no big-bang cutovers, no late-night firefighting.

  • Parallel environments, instant rollback
  • Phased traffic shift, validated at each step
  • Milestone sign-off before every cutover

Where are you starting from?

AlphaVictor app Make it happen The North Face campaign AI development Newell Stores app Software development Juice Jar app App development MPS Data Discovery to deployment The Lir website In-house UK team

How does an app migration to the cloud work?

Clear milestones, each with a defined deliverable you sign off before we move on.

  1. Discovery and Audit

    We map your existing app's dependencies, performance baselines and compliance requirements. You receive a documented audit report and a clear go/no-go recommendation.

  2. Migration Strategy and Architecture

    Based on the audit, we recommend rehost, replatform or re-architect. You get a costed migration plan with timelines, a risk register and architecture diagrams to review.

  3. Environment Setup and Security

    We provision your cloud environment with access controls, encryption and monitoring baked in. You sign off the security configuration before any data moves.

  4. Phased Migration and Testing

    Services move in planned phases. Each one is validated with automated and manual testing. You see progress at every milestone rather than waiting for a single handover.

  5. Cut over / Go-Live

    We coordinate the final switchover with rollback procedures in place. Your users transition with minimal disruption while our team monitors performance throughout.

  6. Optimisation and Handover

    Post-migration, we tune performance, optimise resources and hand over full documentation. You walk away with a system your team can confidently manage and use.

Migration projects we've delivered

Who we are

A decade building software that lasts

300+
Projects shipped to production
2 offices
London and Belfast
Since 2015
The year Myth was founded
Learn more about us

  • Discovery before code

    Every migration starts with an in-person discovery session at our London or Belfast office. We map dependencies, benchmark performance and agree scope before a line of code is written.

  • Senior in-house team

    Our engineers, designers and data specialists work together under one roof. The people you meet in discovery are the same people who build and ship your migration.

  • Cross-sector delivery experience

    We've migrated and modernised systems for clients ranging from sole traders to global brands, spanning healthcare, retail, facilities management and more.

  • Milestone-based engagements

    You see and sign off progress at every phase. No big-bang releases, no surprises. Each milestone has clear deliverables so you stay in control throughout the project.

  • Built and hosted on Azure

    We build and host on Microsoft Azure, meeting UK data-protection requirements. Your migrated application sits on infrastructure our team knows inside out.

  • End-to-end capability

    From UX redesign to back-end re-architecture and ongoing hosting, our team covers the full stack. No subcontracting, no offshoring, no handoffs to third parties.

Myth Digital team reviewing a cloud migration plan during a milestone session

Your Team, Your Milestones, No Surprises

Every migration starts with a structured discovery phase. We audit your application, map dependencies and define a clear scope before any migration work begins.

From there, we deliver through a series of milestones. You always have awareness over what's being built, who's building it and what each phase covers.

Our senior in-house team in London and Belfast work on your project directly. No offshore teams or rotating contractors. The people in discovery are the same engineers who run your migration to production.

  • Senior UK engineers, start to finish
  • Fixed-scope milestones with clear deliverables
  • Discovery-first, so scope is locked early
  • Full visibility on progress every sprint

Is this right for you?

Cloud migration is a significant commitment. Here's how to tell if we're the right partner for your project.

A great fit

  • Your legacy app is hitting scaling limits or rising infrastructure costs
  • Compliance or data residency requirements are driving the move
  • You want a phased approach that allows you to keep focused on your business throughout
  • You value a senior UK team who'll own the project end to end
  • You need discovery before decisions, not a rushed lift-and-shift

Not the right fit

  • You're only looking for the cheapest hosting option available
  • You want everything moved overnight with no discovery or planning
  • Lowest bid wins regardless of team quality or approach
  • You don't have stakeholder buy-in for a structured migration process
  • Your app is brand new and doesn't need modernising or migrating
Cloud migration planning session with the Myth Digital team reviewing application architecture on screen
FAQ

App migration FAQs

What is app migration to the cloud?

App migration involves moving applications from on-premises systems to the cloud or between cloud platforms. This process enables businesses to attain scalability, reduce costs, and modernise operations by adopting cloud-native technologies like serverless computing and containerisation.

How do you choose between rehosting, replatforming and re-architecting?

We run a discovery audit that maps dependencies, benchmarks performance and flags technical debt. If the app is stable and speed matters most, rehosting works. If you need better performance without a full rebuild, replatforming fits. Re-architecting suits apps that need long-term scalability or have significant legacy constraints.

How long does a typical cloud migration take?

Timelines vary with complexity. A straightforward rehost of a single application can take a few weeks. Replatforming or re-architecting a larger system with multiple integrations typically runs over several months. We scope timelines during discovery so there are no surprises.

Will migrating to the cloud cause downtime?

Not if it's planned properly. We use phased cutover strategies, running old and new environments in parallel so users aren't disrupted. Data is replicated and validated before the switch. Most migrations we deliver have zero or near-zero user-facing downtime.

How do you handle data migration and GDPR compliance?

Data is migrated in stages with integrity checks at each step. We host on infrastructure that meets UK data-residency requirements, and our discovery phase includes a security and compliance review. Personal data handling is mapped against GDPR obligations before any migration begins.

Can legacy integrations and on-prem hardware be moved?

Usually, yes. During discovery we map every integration point, API and hardware dependency. Some can move directly; others need an adapter layer or a cloud-native replacement. We prioritise keeping your business processes intact throughout the transition.

What KPIs should we track after migration?

Focus on infrastructure cost versus your pre-migration baseline, application response times, uptime percentage and deployment frequency. We also recommend tracking time-to-recover from incidents. These metrics give you a clear before-and-after picture of what the migration delivered.

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