You will get a reliable API integration for your existing web application
Project details
I build and fix API integrations for existing web applications without unnecessary rewrites.
I can help with REST APIs, authentication, OAuth, webhooks, third-party services, database synchronization, payment APIs, CRM integrations, external data sources and broken API connections.
My stack includes JavaScript/TypeScript, Node.js, Next.js, Python, PHP, PostgreSQL/Supabase and REST APIs.
I focus on clean server-side integration, secure credential handling, useful error messages and code that another developer can maintain later.
Send me the API documentation and a short description of the workflow you need, and I can quickly confirm which package fits.
I can help with REST APIs, authentication, OAuth, webhooks, third-party services, database synchronization, payment APIs, CRM integrations, external data sources and broken API connections.
My stack includes JavaScript/TypeScript, Node.js, Next.js, Python, PHP, PostgreSQL/Supabase and REST APIs.
I focus on clean server-side integration, secure credential handling, useful error messages and code that another developer can maintain later.
Send me the API documentation and a short description of the workflow you need, and I can quickly confirm which package fits.
Programming Languages
JavaScriptCoding Expertise
Cross Browser & Device Compatibility, Localization, SecurityWhat's included
| Service Tiers |
Starter
$100
|
Standard
$200
|
Advanced
$400
|
|---|---|---|---|
| Delivery Time | 1 day | 2 days | 4 days |
Number of Revisions | 1 | 2 | 2 |
Design Customization | - | - | - |
Content Upload | - | - | - |
Responsive Design | - | - | - |
Source Code |
Optional add-ons
You can add these on the next page.
Additional Revision
+$25
Documentation
+$30
Deployment/setup
(+ 1 Day)
+$60
Additional endpoint
(+ 1 Day)
+$40Frequently asked questions
About Arsenii
Full-Stack Developer | React, Next.js, Python, PHP & APIs
Durres, Albania - 2:32 am local time
My main stack is React/Next.js, JavaScript/TypeScript, Python, PHP, Supabase/PostgreSQL and REST APIs.
Recent work includes TiaRental, a multi-vendor car rental marketplace with booking, payments and vendor/admin dashboards, and RedLotusTour, a multilingual tour platform built around responsive booking and content flows.
I also work with browser automation, data processing, Excel/CSV workflows, OpenAI/API integrations and existing codebases that need debugging or extension.
I prefer fixing and extending what already works instead of rebuilding everything unnecessarily.
Have an existing project or specification? Send it over and I can quickly tell you where I’d start.
Steps for completing your project
After purchasing the project, send requirements so Arsenii can start the project.
Delivery time starts when Arsenii receives requirements from you.
Arsenii works on your project following the steps below.
Revisions may occur after the delivery date.
Review the API and current app
I’ll review the API docs, authentication method and how the existing application is structured.
Build or repair the integration
I’ll implement the API connection, data flow and required business logic.