Step 01
Discovery & strategy
We analyze sales models (B2B/B2C), channels, compliance (GDPR, Omnibus), and limits of current tools. We define MVP scope and critical integrations.
E-commerce & headless
Headless commerce platforms (B2B/B2C)
Headless architecture, integrations, and market compliance
GMI Software implements headless commerce on MedusaJS v2 and Next.js when Shopify Plus or monoliths stop matching B2B workflows, ERP and omnichannel needs. 100+ system integrations, 30-person team, estimate within 48 hours after scope review.
We implement modern commerce when off-the-shelf SaaS stops matching your processes: B2B with contract pricing, complex promotions, ERP/PIM/WMS integrations, and owned storefronts. We design a modular architecture — orders, catalog, payments, and logistics connected through APIs. MedusaJS is our primary headless commerce backend — we still recommend a stack aligned with your scale, team, and roadmap.
120+
Delivered projects
100+
System integrations
30
People on the team
Product innovation
E-commerce that feels technically serious
The kind of builds leading brands expect today: headless cores, AI-assisted merchandising, flexible B2B, and payments plus operations without friction - the standard we ship for clients.
Composable commerce
One orders-and-catalog core powering web, mobile, POS, and partner portals. API-first means faster channel experiments and less integration debt.
AI-assisted merchandising
Ranking rules, shelf logic, and recommendations grounded in customer data and behavior - not hand-tuning every campaign.
B2B: lists, contracts, negotiations
Contract-specific price lists, volume breaks, currencies, and payment terms - with permissions and change audit trails.
Checkout: wallets & instant pay
Apple Pay, Google Pay, and local instant methods - less friction at the bottom of the funnel, better mobile conversion.
Inventory & events in near real time
Stock, reservations, and orders synchronized between ERP and frontends - queues, retries, and observable event flows.
Last updated: July 2, 2026
How much does headless e-commerce cost in 2026?
| Scope | Range | Notes |
|---|---|---|
| Medusa MVP + Next.js storefront | EUR 25,000 - 45,000 | 4-6 months |
| B2B with ERP and contract pricing | EUR 55,000 - 120,000 | 6-12 months |
| Marketplace / multi-tenant | EUR 85,000 - 150,000+ | split payments vary |
| USD reference (MVP) | USD 28,000 - 50,000 | international clients |
Ranges after a DDT integration map. Enterprise SaaS TCO is often 2-4x higher on a 3-year horizon - compare with our TCO e-book at gmi.software.
MedusaJS vs Shopify Plus vs Magento - when to go headless?
| Criterion | MedusaJS v2 + custom | Shopify Plus | Magento / Adobe |
|---|---|---|---|
| 3-year TCO (mid B2B) | Lower with custom flows | License + apps + GMV | High hosting + dev |
| Per-account B2B pricing | Native in domain model | Apps / workarounds | Possible, heavy |
| Code ownership | Open source, full | SaaS, limited | Open source |
| MVP delivery time | 4-8 months | 2-4 months template | 9-18 months |
| GMI recommendation | Scale + integrations | Fast D2C start | Legacy migration |
When is headless commerce with GMI not the best fit?
Fast D2C start without custom B2B
Shopify Plus or WooCommerce can be cheaper in year one for a simple store without ERP integrations.
No capacity to run your own backend
Headless needs a team or partner for post-launch updates, compliance and integrations.
Ready-made marketplace out of the box
Without custom development, a marketplace SaaS can launch faster than building modules from scratch.
Cooperation process
How does our cooperation look like?
A transparent process that leads from idea to finished product
Step 02
Architecture & stack
We design services, APIs, and data flows. We pick the engine (often MedusaJS), storefront, and integration layer.
Step 03
Commerce core & catalog
Products, variants, B2B price lists, promotions, inventory — foundations for automation and scale.
Step 04
Storefront & UX
Fast frontends (e.g. Next.js), CRO, accessibility, analytics, and conversion testing.
Step 05
ERP/PIM/WMS integrations
Stock, orders, accounts, and pricing sync. Queues, monitoring, retries, and event audit trails.
Step 06
Launch & evolution
Load testing, rollout, SLA, and backlog. Support for campaigns and peak traffic.
Key benefits
Why choose us?
Business outcomes first—technology is the means, not the end in itself.
Scalable backend
Headless-first APIs — many channels, one data model.
Deep integrations
ERP, PIM, CRM, payments, logistics — coherent data landscape.
Compliance
GDPR, Omnibus, and controlled pricing workflows.
Omnichannel
Same backend for web, mobile apps, and B2B partners.
FAQ
Frequently asked questions about headless commerce
What is headless e-commerce and when should I adopt it?
Headless separates the storefront from the order engine. Adopt it when SaaS limits bite, you need B2B with ERP/PIM/WMS, or omnichannel (web + app + POS) on one backend.
Why MedusaJS instead of Shopify Plus?
MedusaJS is open-source Node.js: full control over B2B logic, no GMV revenue share and lower run cost than Magento. GMI Software specializes in MedusaJS v2 as an enterprise engine.
Which integrations do you support?
ERP, PIM, WMS, payments, OMS, marketplaces - via REST, GraphQL and event queues (Redis, RabbitMQ, SQS).
How long does a Medusa implementation take?
MVP storefront + core: 4-6 months. B2B with ERP: often 6-12 months depending on API quality on your side.
Commerce analytics from day one
In headless commerce, measurement must cover web, checkout, APIs, and integrations. We design GA4/server-side events, B2B funnels, campaign attribution, and dashboards for margin, stock, and conversion.
- server-side events: view_item, add_to_cart, begin_checkout, purchase, quote_request
- channel comparison across web, B2B portal, marketplace, and app
- alerts for checkout API, payments, and ERP/PIM/WMS sync
Technologies
What technologies do we use?
Modern tools and proven solutions for the best results
MedusaJS
Backend
Next.js
Frontend
NestJS
Backend
TypeScript
Language
PostgreSQL
Database
REST / GraphQL
API
Guides and proof
Articles, technology pages and case studies that support your buying decision.
MedusaJS development agency
Implementations, migrations, B2B modules and dedicated Medusa teams.
Read moreMedusaJS 2.0 technology page
Shopify Plus comparison, business modules and v2 architecture.
Read moreMedusa vs Shopify Plus - 3-year TCO
License, apps, GMV fees and B2B integration cost comparison.
Read moreHow much does MedusaJS implementation cost?
EUR/USD ranges: audit, MVP, B2B with ERP.
Read moreMagento to MedusaJS migration
Migration phases, risks and time/cost ranges.
Read moreMedusaJS B2B e-commerce
Contract pricing, ERP and Next.js storefront.
Read moreMedusaJS agency in Europe
Partner selection criteria and GMI model.
Read moreE-book: e-commerce TCO 2026
Compare SaaS vs custom headless on your numbers.
Read moreCommerce project proof
Not just a storefront. Operations, ERP, and B2B in one landscape.
This page shows the pattern behind headless implementations: MedusaJS or a dedicated commerce core, Next.js storefront, ERP/PIM/WMS integrations, and B2B workflows. When a client brand cannot be disclosed, we show the real system scope and risks we deliver.
Explore MedusaJS technologyCommerce operations proofLive-ready
B2B
contract pricing, roles, approval flows
ERP
stock, orders, invoices, event retries
OMS
warehouse routing, returns, statuses
Service scope
What does the service include?
Below is an example scope of work that we adjust to the stage and goals of the project.
B2B and B2C models tailored to your organization
Headless commerce and fast storefronts
MedusaJS as a stack pillar when it is the right fit
ERP, PIM, WMS integrations and automation
Price lists, contracts, and complex promotions
Performance, monitoring, and post-launch care
Ready to start?
Schedule a free consultation and learn how we can help with your project. After our DDT process (Discovery, Design & Technology), we offer a price guarantee and a fixed-price agreement.
Preliminary estimate in 48h
Fixed price after DDT — price guarantee
No commitment
We can sign NDA
Contact
Let's talk
about the project.
Have an app idea or need technological support? Write to us — we'll prepare a preliminary analysis and estimate within 48h. Projects that go through our DDT process (Discovery, Design & Technology) come with a price guarantee and a fixed-price agreement — a key differentiator for us.
Write to us[email protected]
Visit us
GD
gmi.software Sp. z o.o.ul. Jana Heweliusza 11 / 819
80-890 Gdansk, Poland
80-890 Gdansk, Poland
NIP: 5252816287KRS: 0000830003
© 2026 gmi.software Sp. z o.o.