React Migration · Edinburgh
React Migration in Edinburgh
Migrating Edinburgh applications to React, incrementally rather than as a rewrite. The old application contains years of accumulated handling for cases nobody documented — the awkward customer, the legacy data shape, the browser quirk — and a rewrite from the specification reproduces the intended behaviour while losing all of that.
Why this comes up
The problem
A full rewrite was scoped, and the existing application handles a hundred edge cases nobody has written down.
What you get
What we deliver
- Migration route by route, with old and new running alongside each other
- A boundary where the two coexist without fighting over the page
- Shared authentication and session so users never notice the seam
- Existing behaviour captured as tests before the code that produces it is replaced
- Design system introduced progressively rather than as a simultaneous redesign
- The old application actually removed, section by section, as each is replaced
Want this scoped for your business in Edinburgh?
Thirty minutes, no charge, no sales script. You leave with a written summary of what react migration would actually involve — whether or not you use us.
Working in Edinburgh
Scotland
Edinburgh is a financial capital with a strong data science community, and the festival economy creates extreme seasonal load patterns that booking and ticketing systems here have to survive every August.
Financial services and data-led work, plus seasonal systems that have to absorb enormous August load without falling over.
Sectors we work with in Edinburgh
- Financial Services
- Technology
- Tourism
- Higher Education
- Data Science
What we work with
Technologies and platforms
- React
- TypeScript
- Vite
- Playwright
Who we work with
Industries we serve
- SaaS businesses
- Financial services
- Retail
- Professional services
- Technology companies
Why us
Why Edinburgh businesses choose Asionis
- Projects typically launched within 4–8 weeks
- No long-term contracts required
- All team members UK-based
- Dedicated account manager and development team
- Transparent reporting with monthly performance metrics
- Scalable from startup to enterprise
How we work
- Step 1
Free consultation
A 30-minute call to understand the problem. You keep the written summary either way.
- Step 2
Proposal
Scope, timeline and a fixed price, in writing, before anything starts.
- Step 3
Build
Short cycles with regular check-ins, so you see progress rather than hear about it.
- Step 4
Launch and support
We handle the go-live and stay available afterwards.
Other services in Edinburgh
Looking for the full picture? See our React Migration services, everything we do in Edinburgh or browse everything we do.
React Migration in Edinburgh — common questions
- Why not rewrite it properly?
- Because the specification is not the application. Years of small fixes for real situations are embedded in code and absent from any document, and a clean rewrite delivers something that works for the common cases and fails for customers who had been fine.
- How do old and new coexist?
- By dividing at a boundary — route by route is usually cleanest. Each migrated section is complete in itself, users move between them without noticing, and the shared concerns are authentication, session and enough styling that it does not look like two applications.
- Should we redesign at the same time?
- Preferably not. Changing the technology and the interface together means any complaint could be either, and it doubles the scope of a project that is already about reducing risk. Migrate first, then redesign with a codebase that makes it straightforward.
- How do we avoid running both forever?
- Remove the old section as each replacement goes live, and treat the final unglamorous parts as part of the project rather than a phase two. Migrations stall at the last twenty per cent, and running two applications indefinitely is worse than either.
- Do you work with businesses across City of Edinburgh?
- Yes. We are based in Leicester, United Kingdom and work with clients throughout Scotland, including Edinburgh and the surrounding City of Edinburgh area. Most collaboration happens remotely, and we travel for kick-offs and key milestones.
- What kind of Edinburgh businesses do you usually work with?
- Financial services and data-led work, plus seasonal systems that have to absorb enormous August load without falling over. Beyond that we work across Financial Services, Technology, Tourism, Higher Education and Data Science.
- Do you cover the areas around Edinburgh?
- Yes — we work throughout Scotland, including Glasgow. Edinburgh is an urban area of roughly 540,000+, and we take on work across the wider City of Edinburgh region rather than the city boundary alone.
Talk to us about React Migration in Edinburgh
A 30-minute call with someone who would actually work on it. No sales script, no obligation.
- Projects typically launched within 4–8 weeks
- No long-term contracts required
- All team members UK-based
- Dedicated account manager and development team
- Transparent reporting with monthly performance metrics
- Scalable from startup to enterprise