I will add features and integrate apis into your web or mobile app

C
callidusdev
C
callidusdev
Nevfel Gul
add features and integrate apis into your web or mobile app
Full Screen
add features and integrate apis into your web or mobile app

About this gig

I will add new features and integrate APIs into your existing web or mobile application.

I can help with:

React and React Native development

TypeScript and JavaScript

REST API integration

Firebase and Firestore integration

Authentication and user systems

Forms, dashboards and CRUD features

Database integration

Third-party services

Custom app functionality

Whether you need a small feature, API connection, Firebase integration, or a more advanced custom solution, I can work with your existing project structure and add the functionality you need.

Please contact me before ordering and briefly explain your project, the feature you want to add, and any API or service documentation you have.

For complex features or multiple integrations, I can provide a custom offer based on the project scope.

  • Expertise

    • Algorithms & Data structures
    • Debugging
    • Performance
    • Security
    • Design

  • Programming language

    • JavaScript

  • Frontend framework

    • Flutter
    • Next.js
    • React.js
    • Tailwind CSS
    • Htmx

  • Backend framework

    • FastAPI
    • Next.js
    • Node.js
    • Firebase
    • Spring Boot

Get to know Nevfel Gul

Nevfel Gul

Founder and Technical Lead

  • FromTurkey
  • Member sinceSep 2026

  • Languages

    Turkish, English
I am a Computer Engineer and founder of Callidus, a digital studio specializing in full-stack web and mobile development, UI/UX, and automation. We bridge scalable technical architecture (React, React Native, TypeScript, Firebase) with modern design (Figma). Whether you need a cross-platform mobile app or a robust web platform, my team delivers complete solutions. We handle everything from initial prototyping and database structuring to final deployment and app store publishing. Let’s build highly optimized, ready-to-scale digital products.

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Other Software Development Services I Offer

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