Custom API development
REST and GraphQL APIs designed around the operations a business actually performs, versioned, authenticated and documented for the teams that will consume them.
REST · GraphQL
Custom API development and the integration layer under it.
Enterprise system integration for businesses whose software has grown into separate islands: REST and GraphQL API development, third-party API integration, legacy system modernization and the backend services that hold them together — designed so a failure is visible, retryable and survivable.
- Interfaces
- REST · GraphQL · Webhooks · Message queues
- Stack
- Node · PHP · PostgreSQL · Docker · AWS
- Languages
- Türkçe · English · العربية
- Response
- A straight answer on fit within a day
The integration work itself.
An integration is not a script that runs at night. It is a contract between two systems that will both keep changing.
Third-party API integration
Payment providers, carriers, marketplaces, messaging, accounting and government e-invoicing endpoints, wrapped so their outages do not become your outages.
Adapters · Retries
Integration architecture
Queues, idempotency keys, dead-letter handling and reconciliation jobs — the difference between an integration that works and one that works on the sixth month.
Queues · Idempotency
Legacy system modernization
Putting a documented API in front of a system nobody wants to touch, so new software can be built without a rewrite that the business cannot afford to pause for.
Strangler pattern
Backend services and data flow
The services that sit between systems: transformation, validation, scheduling and the observability that tells an operator what moved and what did not.
Node · PostgreSQL · Docker
What a disconnected system costs.
Almost always paid in someone's afternoon, every day, until the integration exists.
The same data is entered three times
Once in the shop system, once in accounting, once in a spreadsheet nobody officially owns.
Connect ERP to e-commerce
Two systems that both hold products, prices and customers, with no agreed contract between them.
An API that changed without warning
A provider ships a new version, the nightly job fails silently, and the gap is found a week later.
Reports that never agree
Sales, stock and finance each produce a different number for the same week, and the meeting is about which one to believe.
A system nobody dares to replace
It runs the operation, the person who wrote it left, and every new requirement has to route around it.
Growth is blocked by manual capacity
Doubling the orders would mean doubling the people who retype them.
Integration work in production.
Edip Saat · edipsaat.com
An integration layer between commerce, ERP, warehouse and accounting — one source of truth per field, and a reconciliation job that proves it.
ERP · WMS · Accounting
DORTEK · dortek.com.tr
PLC lines through a gateway into cloud dashboards — an integration where one end of the wire is a machine.
Read the case study →Hujuzatk · hujuzatk.com
A multi-tenant platform whose booking, pricing and operations modules talk over internal APIs rather than shared tables.
Read the case study →Questions people ask.
Do you build the API, or connect to one?
Both, and usually in the same project. Most integrations need a new API on one side, an adapter on the other, and a service in the middle that owns retries and reconciliation.
How do you handle the other system going down?
The work is queued rather than fired directly. Messages carry an idempotency key, failures move to a dead-letter queue with the reason attached, and a scheduled reconciliation compares both sides so nothing quietly disappears.
Can you work alongside our in-house team?
Yes. A common arrangement is that I own the integration layer and its architecture while your team owns the product they already know — with weekly deployments and a written changelog so nobody has to ask what changed.
Have a complex system to build or scale?
Tell me what you are trying to build, automate or scale. You get a straight answer on fit within a day — and a name to call if it is not me.
- [email protected]
- linkedin.com/in/zakaria-haj-mohamad-87188b11b