Backend API Developer for ERP Integration

Project Type: Remote, fixed-price project Duration: 5–8 effective working days Budget: USD $800–$1,200 Engagement: One-time project; no full-time position Project Overview We operate a cross-border dropshipping fulfillment business and have an existing self-built fulfillment platform: https://fulfillment.edpro-app.com/ We need an experienced backend developer to integrate our platform directly with the Mabang ERP Open API. This is a small, clearly defined API integration project. We are looking for an individual freelancer who has hands-on experience integrating Mabang ERP Open API. Integration Flow The required integration is: Mabang ERP → Our Fulfillment Platform Receive/pull order information from Mabang Create/write the corresponding order into our fulfillment platform Our Fulfillment Platform → Mabang ERP Send fulfillment/shipping status Send logistics tracking number after shipment Not Required The following are explicitly out of scope: Inventory synchronization Product/SKU synchronization Refund processing Return processing Front-end development Large-scale refactoring of our existing platform Inventory will be maintained manually by our team. Responsibilities 1. Mabang API Authentication Implement Mabang Open API authentication Implement HMAC-SHA256 signature generation/verification according to Mabang documentation Configure and test the sandbox environment Troubleshoot API request/response issues 2. Order Integration Pull/receive orders from Mabang ERP Map the required order fields Create orders in our existing fulfillment platform Implement basic duplicate-order prevention Handle API errors and failed requests 3. Shipping & Tracking Callback After an order is fulfilled/shipped in our platform: Update the relevant order status in Mabang Send the logistics carrier information where required Send the tracking number to Mabang Ensure duplicate callbacks/requests do not create inconsistent data 4. Reliability & Logging Implement basic: API error handling Request/response logging Retry logic where appropriate API rate-limit handling Duplicate-order prevention We do not require a complex enterprise-level middleware system. The goal is a reliable and maintainable integration for our current business volume. Technical Requirements Mandatory Proven hands-on experience with Mabang ERP Open API integration. Please describe your previous Mabang integration experience in your proposal. You should also be comfortable with: RESTful APIs HTTP requests Webhook/callback development HMAC-SHA256 JSON API authentication Error handling and logging Backend Language Experience with at least one of: PHP / Laravel Java Python Go Node.js Our existing fulfillment platform uses PHP/Laravel + MySQL, so Laravel/PHP experience is a strong advantage. Important – Mabang Experience Applicants without actual Mabang ERP Open API integration experience may still apply if they have strong ERP/WMS API integration experience, but Mabang experience will be strongly preferred. Please do not simply state "I have API integration experience." In your proposal, please answer: 1. Have you previously integrated Mabang ERP Open API? 2. Which Mabang API functions/endpoints did you work with? 3. What data did you synchronize? 4. What programming language/framework did you use? 5. How long would you estimate this project will take? 6. What is your fixed-price quote? Deliverables The final delivery must include: Complete source code for the Mabang integration module Database changes/scripts, if required API configuration documentation Environment configuration instructions Secret-key/AppKey configuration instructions Sandbox testing Production environment configuration assistance Production verification with a small number of real orders Basic troubleshooting documentation All integration source code produced for this project must be handed over to us upon final payment. Project Milestones Milestone 1 – Authentication & Sandbox Connection — 20% Mabang authentication completed HMAC-SHA256 signature working Successful API communication with Mabang sandbox Milestone 2 – Order & Shipping Integration — 50% Order data successfully received from Mabang Orders successfully created in our fulfillment platform Shipping status successfully sent back to Mabang Tracking numbers successfully synchronized Basic duplicate prevention and error handling completed Milestone 3 – Production Verification & Handover — 30% Production environment configured Small-volume real-order testing completed Source code delivered Documentation delivered Final bugs fixed Client Provides We will provide: Mabang Open Platform AppKey Mabang AppSecret Mabang sandbox credentials Required API documentation Access to our existing platform/API as required Technical contact for joint testing Scope & Change Management This project is limited to the integration described above. Any additional requirements outside the defined scope will be discussed and separately estimated before development. The integration should be implemented directly between our fulfillment platform and Mabang Open API. No third-party middleware, paid API gateway, or external integration platform should be introduced without our prior approval. Project Type This is a one-time fixed-price project. We are not looking for a full-time developer or long-term employment. We prefer an experienced individual freelancer who can work independently, communicate clearly, and complete the integration within approximately 5–8 effective working days.