The verdict in three sentences
For a 200,000-line PHP 5.6 application with no tests, a full rewrite (big bang) costs 650,000 to 1,700,000 AED (about 150,000 to 400,000 EUR) in Dubai in 2026, with a high regression risk on cut-over day. A module-by-module migration using the strangler pattern costs 60 to 70 % of that amount, spread over 12 to 18 months, and keeps the business running throughout. For an insurance broker whose application carries policies, commissions and compliance, the second option is almost always the right one.
Why PHP 5.6 is no longer an option
PHP 5.6 has had no security patches since the end of 2018. For an application processing policyholders' personal data, that is a compliance problem under the UAE Personal Data Protection Law and with partner insurers' vendor due diligence. Add zero tests, fewer and fewer developers willing to work in that context, and hosts withdrawing old versions.
| Debt indicator (2026 order of magnitude) | Typical PHP 5.6 legacy situation | Target after migration |
|---|---|---|
| Supported version | End of support since 2018 | PHP 8.3 or 8.4, or Node.js LTS |
| Test coverage | 0 % | 60 to 80 % on business code |
| Average time for a simple change | 5 to 8 days | 1 to 3 days |
| Production incidents per month | 6 to 12 | 1 to 3 |
| Release process | Manual, once a month | Automated, several times a week |
| Onboarding a new developer | 6 to 10 weeks | 2 to 3 weeks |
Big bang or strangler: the budget comparison
The strangler fig pattern places a routing layer in front of the existing application, then rewrites one module at a time (quoting, policy administration, commissions, reporting). Each migrated module replaces the old one in production. The legacy application shrinks until it disappears.
| Criterion (2026 market estimate, Dubai) | Big bang rewrite | Module-by-module migration |
|---|---|---|
| Budget for 200,000 lines | 650,000 to 1,700,000 AED | 60 to 70 % of big bang, or 390,000 to 1,190,000 AED |
| Day rate of senior profiles | 2,000 to 3,200 AED | 2,000 to 3,200 AED |
| Duration | 9 to 15 months with no interim release | 12 to 18 months with releases every 6 to 8 weeks |
| Freeze on business changes | Yes, often 6 months or more | No, changes possible on migrated modules |
| Regression risk | Concentrated on a single cut-over | Spread module by module, rollback possible |
| Dual maintenance | Long, old and new in parallel | Limited to the module in progress |
| Probability of budget overrun above 30 % | High | Moderate |
The 30 to 40 % gap comes from reusing the data schema, removing dead features discovered along the way (often 15 to 25 % of the code) and avoiding a giant acceptance phase at the end of the project.
The regression risk matrix
| Risk | Probability | Impact | Mitigation |
|---|---|---|---|
| Commission calculation differs after migration | High | Critical | Characterisation tests: replay 12 months of real data and compare to the fils |
| Loss of undocumented business rules | High | High | Workshops with account handlers, code reading before each module |
| Data inconsistency between old and new | Medium | High | Shared database during transition, controlled sync |
| Broken insurer integration | Medium | High | Automatically tested API contracts |
| Scope creep | High | Medium | Rule: migrate like-for-like, enhancements afterwards |
| The only developer who knows the legacy code leaves | Medium | Critical | Pairing and documentation from month one |
The first investment to make, whichever option you choose: 15 to 25 days writing characterisation tests on critical calculations, or 35,000 to 80,000 AED. It is the cheapest insurance in the project.
Mini case study
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Rania, CIO of a 150-employee insurance brokerage in Dubai, receives two proposals. The big bang is priced at 1,200,000 AED over 12 months, with a 7-month freeze on changes. The progressive migration is priced at 780,000 AED (65 %) over 15 months, in six modules. She estimates each month of freeze costs the firm about 38,000 AED in postponed commercial features, or 266,000 AED for the big bang. Compared cost: 1,466,000 AED against 780,000 AED, before even pricing the risk of a failed cut-over. Rania approves the progressive migration and starts with the commissions module, the riskiest, with 18 days of characterisation tests.
FAQ
How much does it cost to migrate a 200,000-line PHP application?
As a 2026 order of magnitude in Dubai, 650,000 to 1,700,000 AED for a full rewrite, and 60 to 70 % of that for a progressive migration. The gap depends mostly on data schema quality and the number of integrations.
Can we just upgrade from PHP 5.6 to PHP 8 without rewriting?
Sometimes, for recent and well-structured code, with 30 to 80 days of work. On 200,000 lines with no tests and no framework, compatibility breaks often make this route as expensive as a module-by-module migration.
Which modern stack should we choose?
PHP 8 with Symfony or Laravel keeps existing skills; Node.js with TypeScript or Python suit a changing team. Favour what you can hire for in Dubai: day rates and availability vary by 10 to 20 % across technologies.
How do we avoid regressions on financial calculations?
Replay real history, for example 12 months of policies, through old and new systems, and require zero difference to the fils before each release. These tests cost 35,000 to 80,000 AED and prevent far more expensive disputes.
Should we keep the original vendor?
Not necessarily. A new vendor will plan 10 to 20 days of audit, about 25,000 to 65,000 AED, to map the code before committing to a quote.
Let's scope your project. We audit your legacy application, map its modules and price a progressive migration plan with milestones and characterisation tests. Detailed quote within 48 h. WhatsApp +221 77 596 93 33, or explore our custom web applications.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
