Your applicationsmodernised,without disruption.
Audit, migration plan, progressive rebuild. We keep what works, replace what blocks, without freezing your developments or creating permanent dependency.
Three principles,
that distinguish modernisation from a rewrite.
An application that slows down your business doesn’t need to be discarded. It needs to be read, understood, and rebuilt piece by piece—while operations keep running.
Progressive migration
Coexistence of old and new until full switch. Your teams keep working while we modernize. No business interruption, no freeze on ongoing developments.
We take over the existing, we don’t discard it
PHP, Java, .NET, Symfony, legacy Rails, Bubble, Airtable: we audit, extract what holds value, rebuild what needs to be. No rewrite for the sake of it.
Handover to internal teams included
Documentation, code reviews, training. Our goal isn’t to become indispensable. You take back control whenever you want—it’s part of the scope, not an add-on.
AI speeds up the takeover,
not blindly.
Most integrators modernize manually. We use AI to read, rebuild, and document faster and more reliably—with human oversight at every step, and your code never leaving your premises.
Understanding a codebase no one masters anymore
AI agents read and map a massive, undocumented codebase: dead code, hidden dependencies, missing documentation reconstructed. The riskiest step in a takeover becomes quantifiable—we illuminate blind spots before any commitment.
Migrating without breaking
Generation of non-regression tests to ensure old/new equivalence, assisted porting (PHP → TypeScript), documentation produced as we go. AI handles the repetitive; our devs retain architectural decisions.
Documentation that doesn’t expire
Documentation generated and kept up to date alongside the code, so your teams can take over—without depending on us or static docs delivered on the final day.
Four modernisation scenarios.
Four concrete cases with documented deliverables and production feedback. Not an abstract promise of “we can take over anything” — a scope we commit to.
Aging monolithic application
Outdated stack, heavy technical debt, no one knows how to evolve it. We audit, plan, and replace module by module — without breaking what’s running.
No-code tool that has hit its limits
Bubble, Airtable, FlutterFlow that can no longer handle the load or business rules. Switch to maintainable code without losing data or users.
SaaS locked into an old stack
A product that runs but is becoming hard to maintain, evolve, or pass investor audits. Targeted reconstruction of critical modules.
Hard-to-maintain internal tool
Custom ERP, in-house back-office, business scripts accumulated over the years. We modernise without rewriting everything — we take over what holds value.
What we modernise towards.
Scroll’s standard target stack — modern, maintainable, recruit-friendly. No exotic tech with no future. The source code returns to you, in your Git, with no permanent dependency on Scroll.
Front
Ops / Hosting
Monitoring
JeRêveDuneMaison: from a rigid business app to a modern stack.
Business application for managing property hunter mandates, clients, and administrators. Progressive migration to Next.js + Supabase + PostgreSQL, with full documentation and support. Coexistence of old and new systems until the final switch.
Read the full case studyFour steps, no big bang.
A dedicated team from scoping to delivery with a dedicated project lead
The existing system, independently.
System mapping, identifying bottlenecks, assessing technical debt, defining success criteria. Deliverable: diagnosis + migration plan + estimate. 1 to 3 weeks.
The migration plan.
Which modules to keep, which to replace, in what order, and how they will coexist. Validation with your IT and business teams before any development. No surprises along the way.
Module by module.
2-week sprints, delivery by modules. Your users switch over gradually, with no disruption. Automated testing and monitoring from the first module in production.
Final switch and autonomy.
Decommissioning the old system, team training, final documentation. Progressive handover to internal teams if desired — your IT regains control before the contract ends.
What you take away at the end.
A modernisation is only successful if your teams regain control. The source code returns to you, your devs are trained, and legacy subscriptions are terminated. No irreversible steps.
Source code is yours
TypeScript reviewed, tested, and documented. In your Git, under your licence. Not a blob exported from a third-party tool.
Data preserved
Historical data migration, integrity verified, process documented. User history is never compromised.
Teams trained
Training sessions, pair programming, documentation. Your devs take back control before the contract ends. No permanent dependency.
Legacy decommissioned
The old system is phased out gradually, module by module, after validated migration of each scope. No abrupt shutdown.
Frequently asked questions
The most common questions we hear during scoping. If yours isn’t here, get in touch!
Should we modernise now?
Modernisation is never urgent… until an event makes it urgent. If any of these signals resonate, the audit (1 to 3 weeks) tells you where you stand—with no reconstruction commitment.
Due diligence before a funding round or acquisition
An investor or acquirer will audit your code. Uncontrolled debt lowers valuation—or kills the deal.
The last developer who knows the system is leaving
When the only person who understands the legacy code departs, every update becomes a gamble. Mapping restores knowledge to the team, not to one individual.
A technology reaches end of support
PHP 7, an unmaintained framework, an abandoned dependency: once support ends, every vulnerability remains open. Modernising beforehand means choosing your own timeline.
A security incident has raised the alarm
Intrusion, leak, failed audit: legacy becomes a board-level risk. We secure by rebuilding critical modules, not by patching.
Do you have an application slowing down your business? Independent audit in 1 to 3 weeks.
75011 Paris