The verdict in three sentences
A headless replatform in Berlin costs EUR 60,000-160,000 over 16-24 weeks, with a composable stack and GDPR-compliant EU hosting. The payoff is not cosmetic: better Core Web Vitals translate into a 10-20 % conversion uplift and full freedom on the front end. Headless is justified when a SaaS monolith throttles your performance, your design or your technical roadmap.
Monolith vs headless: the 2026 costs
Headless separates the front end (Next.js, Vue) from the commerce back end (Commercetools, Medusa, Saleor). This unlocks customisation but adds integration complexity.
| Item | Headless (EUR) | Monolith SaaS (EUR) |
|---|---|---|
| Initial build | 60,000 - 160,000 | 20,000 - 55,000 |
| Annual licence | 15,000 - 45,000 | 18,000 - 60,000 |
| EU hosting / yr | 6,000 - 18,000 | Included |
| Front-end flexibility | Full | Theme-limited |
| Timeline | 16 - 24 wks | 10 - 16 wks |
| Core Web Vitals | Excellent | Variable |
Headless concentrates the investment in the front end and orchestration; the monolith is faster to launch but caps performance and design.
Performance and conversion: what speed returns
Google's Core Web Vitals weigh on SEO and conversion. Here are the 2026 targets and their estimated impact (order of magnitude).
| Metric | Before (monolith) | After (headless) | Effect |
|---|---|---|---|
| LCP | 3.8 s | 1.4 s | +SEO, +conv. |
| INP | 320 ms | 90 ms | Smoothness |
| CLS | 0.22 | 0.03 | Trust |
| Conversion rate | 1.8 % | 2.1 % | +17 % |
| Average order | EUR 95 | EUR 98 | +3 % |
Moving from 1.8 % to 2.1 % conversion on constant traffic means +17 % orders, often the single line that funds the replatform on its own.
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Mini case study
Lena, e-commerce lead at a Berlin DTC fashion brand, does EUR 4.2M in online revenue at 1.8 % conversion. Her SaaS monolith shows a 3.8 s LCP and blocks front-end optimisation. She invests EUR 95,000 in a headless replatform on Next.js + Commercetools. LCP drops to 1.4 s and conversion rises to 2.1 %, i.e. +17 % orders. On EUR 4.2M that is roughly EUR 714,000 in additional revenue; even at 12 % net margin, the annual gain (~EUR 85,000) pays back the project in a little over a year.
FAQ
What does a headless replatform cost in Berlin in 2026? EUR 60,000-160,000 depending on catalogue scope, integrations (ERP, PIM, payments) and front-end complexity. A standard DTC project lands around EUR 90,000-110,000.
Does headless really improve conversion? Indirectly, via speed: better Core Web Vitals typically deliver 10-20 % more conversion at constant traffic and offer.
Which composable stack should I choose? Commercetools and Saleor for enterprise, Medusa for open-source control, with a Next.js front end hosted in the EU for GDPR compliance.
What is the recurring cost? Budget EUR 15,000-45,000 in back-end licence per year plus EUR 6,000-18,000 hosting, weighed against the value of the performance gains.
When should you NOT go headless? If your catalogue is small, traffic modest and SaaS theme fast: the integration overhead would not pay back for several years.
Let's scope your project. Give us your online revenue, current Core Web Vitals and integrations: we cost the headless replatform and its ROI. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
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.
