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Fiverr Pro
English
$
USD
I will do rest API integration, webhooks and third party API integration
Zeinuar
About this gig
I'm a backend engineer with 10+ years connecting systems that have to work reliably every day. If you need an external API, webhook, or third-party service wired into your backend done right, not just "it works once" I can help.
What you get:
- Clean REST API / webhook integration in .NET / C#
- Retries and idempotency, so nothing double-fires or gets lost
- Signature verification on incoming webhooks
- Clear error handling and logging
- OpenAPI / Postman documentation
- Source code handed over you own everything
Why me:
Integrations fail quietly in production. I build them to be safe to re-run, easy to trace, and tested on the parts that matter so you are not debugging silent failures months later.
Packages:
- Basic: one integration or webhook
- Standard: up to 3, or two-way, with a sync/reconciliation job
- Premium: a full multi-system hub with monitoring and handover
I work in clear written/async communication. Message me with your API docs or use case before ordering, so I can confirm scope and delivery.
Get to know Zeinuar
Zeinuar
Backend and Integration Engineer, NET and PostgreSQL specialist
- FromIndonesia
- Member sinceJun 2020
Languages
Indonesian, English
Senior backend engineer, 10+ years building the systems businesses run on daily — REST APIs, third-party and payment-gateway integrations, PostgreSQL/MySQL database design, scheduled jobs, and data migration off legacy systems. I take work that is clearly scoped and delivered on schedule: clean data models, a full audit trail, and jobs that run reliably whether or not anyone is watching. Need the backend or integration behind an app, built to be traceable and handed over documented? I can help. I work mainly in written/async communication, so nothing gets lost.
FAQ
What do you need from me to start?
Your target API's documentation and sandbox/test credentials (or the webhook spec), plus a short note on what should happen. If anything is missing, I'll tell you exactly what I need before we begin.
Which APIs or services can you integrate?
Any REST or webhook-based service — payment gateways, CRMs, shipping, messaging, accounting, and custom internal APIs. Built in .NET / C# with PostgreSQL or your existing database. Unsure it's possible? Send me the docs first.
Do I get the source code?
Yes, always. Full source plus OpenAPI/Postman docs are handed over to you. You own everything — nothing is locked to me.
What if something breaks after delivery?
Each package includes revisions, and integrations are delivered tested, with retries and idempotency built in. For new endpoints or changes after handover, we agree a small follow-up scope.
Can you build the front-end too, or deliver faster?
I focus on the backend and integration layer, delivered on the timeline shown so nothing is rushed. Front-end UI isn't included, but I provide clean integration points your front-end dev can plug into. For urgent timelines, message me first to check availability.
