You will get a third-party API integration for your existing web application
Project details
I will help you connect your existing web application to a third-party service and turn the integration into a working feature your users or team can actually use.
Depending on what is already available in your application, I can connect an existing interface, add a simple new screen, build the required backend integration, set up API key or OAuth authentication, map the data, handle errors, and test the completed workflow.
This project can be used for integrations with CRM systems, AI tools, payment providers, messaging platforms, data services, and other business applications.
Before I start development, I will review what you want the integration to achieve, the available API documentation, and the relevant part of your application. This helps make sure the selected package matches the work required and avoids surprises during development.
Each package covers one third-party service and one agreed feature. Projects involving several external services, large data migrations, ongoing background synchronization, major architecture changes, or broader application development may need a separate estimate.
Depending on what is already available in your application, I can connect an existing interface, add a simple new screen, build the required backend integration, set up API key or OAuth authentication, map the data, handle errors, and test the completed workflow.
This project can be used for integrations with CRM systems, AI tools, payment providers, messaging platforms, data services, and other business applications.
Before I start development, I will review what you want the integration to achieve, the available API documentation, and the relevant part of your application. This helps make sure the selected package matches the work required and avoids surprises during development.
Each package covers one third-party service and one agreed feature. Projects involving several external services, large data migrations, ongoing background synchronization, major architecture changes, or broader application development may need a separate estimate.
Programming Languages
JavaScript, ASP.NET, TypeScriptCoding Expertise
Cross Browser & Device Compatibility, Performance Optimization, SecurityWhat's included
| Service Tiers |
Starter
$99
|
Standard
$299
|
Advanced
$499
|
|---|---|---|---|
| Delivery Time | 2 days | 4 days | 7 days |
Number of Revisions | 1 | 1 | 2 |
Number of Pages | 0 | 1 | 2 |
Design Customization | - | ||
Content Upload | - | - | - |
Responsive Design | - | ||
Source Code |
Optional add-ons
You can add these on the next page.
Additional Revision
+$35
Additional API-powered action
(+ 1 Day)
+$75Frequently asked questions
About Katerina
Full-Stack Developer | APIs, C#, ASP.NET Core, React, Node.js, SQL
Sderot, Israel - 10:21 am local time
I work with C#, ASP.NET Core, .NET, SQL/PostgreSQL, React, and Node.js when needed. I can help with backend development, API design, database design, third-party integrations, admin panels, internal tools, bug fixing, performance improvements, and deployment support.
My experience includes production systems, web control panels, mobile-connected backends, data-processing workflows, background jobs, internal tools, and the full development lifecycle from planning and architecture to implementation and deployment.
I can also help with practical AI integrations, including OpenAI/LLM API features, AI-powered workflows, RAG/backends, vector search, and connecting AI functionality with existing APIs, databases, and business logic.
I’m comfortable working with existing codebases, investigating issues, improving maintainability, and turning unclear technical problems into practical solutions. I value clear communication, reliable delivery, and clean, maintainable code.
Steps for completing your project
After purchasing the project, send requirements so Katerina can start the project.
Delivery time starts when Katerina receives requirements from you.
Katerina works on your project following the steps below.
Revisions may occur after the delivery date.
Review requirements and confirm scope
I review your requirements, the available API documentation, and the relevant part of your application to confirm the best approach before development begins.
Build the integration
I build the agreed integration across the frontend, backend, or both, including authentication, data handling, and clear error states where needed.