API Authorization Backend for Existing App

@rahuliitm69

Hi there, I can help you rebuild this backend. We just need to log the app's network requests, see what endpoints it's hitting, and build a new server that mimics those exact JSON responses and auth loops so the app functions again. My preferred stack for this is Node.js and PostgreSQL because it makes it incredibly easy to match exact token structures (like JWT or cookies) and data formats. I have plenty of experience setting up secure login systems and API integrations, so handling the database structure and session validation will be straightforward. I estimate it will take about 2 weeks to map the traffic, build the database, and test everything. I'm available to start this week and can give you a fixed price once we see how many endpoints the app actually uses. Is this a mobile or web app? Let’s jump on chat and discuss. Thanks, Rahul A.

@axiomswb

I see you need a secure backend microservice built to replicate and support the expected authentication, token management, and session validation flows of an existing frontend environment. Here is my direct execution blueprint for this architecture: Traffic Mapping: I will inspect your application's network traffic requests using Postman/Wireshark to cleanly document the exact payload objects, header formats, and account status checks your app expects. Secure API Architecture: I will build a lightweight, stateless Node.js/Express API utilizing JSON Web Tokens (JWT) for session management, modern password hashing, and role-based access control (RBAC). Database & Handover: I will configure a relational MySQL or PostgreSQL schema for secure asset allocation and supply clean, technical documentation alongside environment deployment guides. Are your application's existing frontend network calls structured around standard REST API payloads, or does the frontend rely on specific GraphQL query structures to fetch user session data?

@durgesh8527

Drawing from my extensive 10+ years of experience as a full-stack developer, I'm confident that I can deliver the impeccable backend authentication system and API integration you require for your existing application. My expertise lies in building secure and efficient API backends using a multitude of technologies including Node.js, Python, PHP, Laravel, and Golang - similar to those you've listed. These experiences coupled with my understanding of databases (MySQL, PostgreSQL, MongoDB) and strong debugging skills using tools like Postman makes me an ideal fit for this project. For this project, you can expect a meticulously crafted backend authentication system tailored to meet your specific demands. I will implement robust user/account management structures as well as API endpoints complemented with foolproof session/token handling logic. Keeping in mind the importance of speed and efficiency, I'll ensure all database setups are optimized for swift access control. Going beyond just delivery of a working solution, I'll provide detailed guidance on deploying the new backend service and comprehensive technical documentation

@BSDesigners

Hello, I will create a robust backend authentication system and API service for seamless integration with your existing application. This will include understanding current workflows, setting up necessary endpoints, database structures, and providing thorough testing and documentation. Let's discuss further to initiate the project. Thanks

@anshumanvermaUK

Hi, I can analyze your app’s login/API flow and build a compatible backend with secure authentication, session/token handling, and required endpoints. I’ve worked on similar reverse-engineered API integrations and auth systems using FastAPI/Node with PostgreSQL. Thanks Anshuman

@CreativeIshan

With over a decade of experience in web development, particularly in building API-based applications, I believe I'm the ideal candidate for your project. I have an in-depth understanding of authentication systems, user validation, session management, and token-based access, which are all essential for your backend API setup. This is complemented by my proficiency in multiple backend languages such as Node.js, Python and PHP to ensure a smooth integration to your existing environment. In previous projects paralleling your requirements, I've successfully created robust backends that facilitated user login, session/token handling, account status checks and efficient API responses. Notably, my ability to inspect application traffic and understand API workflows help me immensely in resolving compatibility challenges; skills reaffirmed by my adeptness with widely-used tools like Postman and Wireshark for debugging and API testing. Additionally, through my career I have dealt with various databases including MySQL and MongoDB which puts me in a good position to configure the database structure needed. Coupled with my passion for clean coding practices and thorough documentation, you can be assured of receiving clean code, clear instructions for deployment and maintenance, as well as the utmost diligence during the testing phase till your application works perfectly with the new backend service. Let's make your app's backend as awesome as its frontend!

@abhishek060

Hi This looks like a backend integration-focused task where the key challenge is reconstructing a compatible authentication layer that matches an existing app’s request/response behaviour without breaking current flows. I can help you build a clean, stable backend API that integrates smoothly with your existing application and handles authentication, sessions, and user validation correctly. What I will deliver: • Authentication API (login, validation, session/token handling) • User/account database structure • Required REST endpoints matching your app flow • Secure access control and session management • Tested integration with your existing application • Deployment guide + technical documentation Approach: I’ll first analyse the current app communication flow, map expected requests/responses, then build a backend that mirrors it exactly to ensure compatibility and avoid frontend changes. Experience: I’ve worked on backend systems involving authentication layers, API reverse-engineering, and integration with existing mobile/web apps using Node.js and Python-based stacks. Timeline: 3–6 days depending on complexity of current app flow. Quick question: Do you already have access to API logs or request samples from the current application, or should I extract the full flow from traffic analysis? Regards, Abhishek

@tadinhkien

Greetings, Thank you for considering my application for this project. As an AI Engineer and Python Developer with over 8+ years of experience, I bring a wealth of knowledge and expertise in the field of Python, Deep Learning. I have carefully reviewed the project description and am eager to discuss your specific needs and requirements in more detail. My commitment is to provide dedicated support and consistent follow-up throughout the project's lifecycle. Please feel free to reach out to me to further discuss how I can contribute to the success of your project. Looking forward to the opportunity of working together. Best regards, KuroKien

@guruvenkat

Hello I am having 15+ years experience in PHP/MYSQL, C++, python and Flutter Development. I can help you to do this task very quickly. Thanks Venkateswaran

@Govind7877190814

Hi, I would like to grab this opportunity and will work till you get 100% satisfied with my work. I just applied after read your job posting carefully and I believe that I am good fit to your project. I'm a serious bidder. I will satisfy you with my high skills! I am an expert which have 10+ years of experience on Mobile App Development, iPhone, User Interface / IA, PhoneGap, Mobile App Testing, Swift, Google Maps API, Web Development, iOS Development, Mobile Development I am looking forward to meet you to discuss the further detail about this project. Looking forward to hearing from you. Warm Regards

@letswork92

Hello, I understand you're seeking an experienced backend developer to establish a robust authentication and API backend for your application. Ensuring seamless user validation and session handling is critical for maintaining a secure and efficient workflow. With over 12 years of experience in backend development, I have successfully built similar systems using technologies such as Node.js, Firebase, and AWS. My proficiency includes creating customizable API endpoints, managing user accounts, and implementing token-based access to ensure smooth integration with existing applications. I have previously worked on projects that involved intricate login systems and API communication flows, allowing me to quickly identify potential compatibility issues during the testing phase. I can also provide comprehensive technical documentation to support your deployment process. Could you share more details about the current technology stack used in your application? Looking forward to collaborating on this project!

@Kishoreindia

Dear Sir/Madam, I am an experienced Python Developer with strong expertise in building scalable backend systems, APIs, automation tools, and full-stack applications. I specialize in delivering clean, efficient, and production-ready solutions. I have successfully developed and deployed multiple live applications including healthcare platforms, legal service apps, school management systems, fintech apps, and real-time communication systems. My Core Python Expertise ✔ Django & Django REST Framework ✔ FastAPI (High-performance APIs) ✔ Flask ✔ SQLModel / SQLAlchemy ✔ PostgreSQL / MySQL / MongoDB ✔ Supabase Integration ✔ Authentication (JWT, OAuth) ✔ Payment Gateway Integration (PhonePe, Razorpay, Stripe) ✔ Web Scraping (BeautifulSoup, Selenium) ✔ Automation Scripts ✔ WebSocket & Real-time Systems ✔ Docker Deployment ✔ AWS / VPS Deployment ✔ REST API Design & Optimization What I Can Build For You Secure REST APIs SaaS backend architecture Admin dashboards Real-time chat systems Payment systems Data processing systems Microservices architecture AI/ML API integration Custom business logic systems Recent Project Experience Healthcare booking & wallet system Legal consultation backend platform School ERP & management API Fintech wallet & transaction management Real-time chat application (WebSocket + MQTT) Location-based services & geo APIs

@monicasynthesis

Hello, I’ve gone through your job description and understand you need a backend developer to build an authentication and API layer for your existing application, including login flow, session management, and database integration. With 5+ years of experience in backend development and API architecture, I’ve built similar authentication systems and integration backends for web and mobile applications. What I can help you with: • Secure authentication API (login, validation, session/token handling) • User/account management with database design and access control • Full API development, testing, debugging, and deployment support Warm regards, Monica Bhatia

@DigitalNightOwl8

Hello, Greetings , Good evening! I’ve carefully checked your requirements and really interested in this job. I’m full stack node.js developer working at large-scale apps as a lead developer with U.S. and European teams. I’m offering best quality and highest performance at lowest price. I can complete your project on time and your will experience great satisfaction with me. I’m well versed in React/Redux, Angular JS, Node JS, Ruby on Rails, html/css as well as javascript and jquery. I have rich experienced in Backend Development, Database Management, PHP, Mobile App Development, Software Architecture, Node.js, API Development and MySQL. For more information about me, please refer to my portfolios. I’m ready to discuss your project and start immediately. Looking forward to hearing you back and discussing all details.. Your Sincerely

@nitinjohnson316

Hi, I have experience building backend authentication systems, API integrations, session/token handling, and database-driven applications using Laravel, Node.js, Python, and MongoDB/MySQL. I can review the existing application workflow, analyze the login/API communication process, and build a compatible backend service with proper authentication, user validation, session management, and required API endpoints. I also have experience debugging APIs and testing integrations using tools like Postman, Fiddler, and Burp Suite to ensure smooth compatibility with existing applications. I can start immediately and will provide deployment support, documentation, and testing assistance until everything works correctly. Looking forward to hear from you.

@chiragardeshna

Hi there, Strong alignment with this project comes from experience building backend authentication systems, API integrations, and secure session management for applications requiring stable communication workflows and compatibility handling. Clear understanding of the requirement to inspect existing login flows, analyze request/response behavior, and develop compatible backend APIs with authentication, validation, token handling, and account management. Hands-on expertise with Node.js, Python, MySQL, PostgreSQL, Postman, and API debugging tools ensures reliable endpoint development, structured databases, and smooth backend integration. Risk is minimized through traffic analysis, response validation, compatibility testing, secure token workflows, and detailed deployment documentation for long-term maintainability. Available to start immediately happy to discuss workflow, timeline, or share similar backend integration experience. Recent work: https://www.freelancer.com/u/chiragardeshna Regards Chirag

@jaroslavcaprata

Hi, there. I have 8+ years of backend development experience with strong expertise in authentication systems, API integration, session management, and database architecture. I have completed 35+ backend projects involving Node.js, PHP, Python, MySQL, PostgreSQL, MongoDB, and secure token-based authentication workflows. I have also worked on application reverse-engineering tasks where understanding existing request/response structures and rebuilding compatible backend services was required. For your project, I will first analyze the current application login flow and API communication process to fully understand authentication behavior, validation rules, and session handling requirements. I can build a stable backend API with secure login endpoints, token/session management, user access control, account validation, and database structure aligned with the application workflow. I am experienced with API debugging and traffic inspection tools including Postman, Fiddler, and Wireshark, which helps identify compatibility issues quickly. The final delivery will include clean and scalable backend code, deployment guidance, API documentation, and testing support until the application works smoothly with the new backend environment. Thank you, Jaroslav Caprata

@rudracompuTech

Hi, I’m confident I can deliver your API Authorization within the expected timeline while maintaining quality and smooth communication throughout the project. Let’s discuss your feature scope and start building your product efficiently. Thanks

@nikhilroyjs

Hello there, Your API Authorization Backend project is a perfect fit for my expertise! I specialize in building secure, efficient authentication systems and seamless API integrations. 1. **Auth Expertise:** Strong experience implementing token/session-based auth & user validation, especially with Django's powerful auth system and Firebase. 2. **Project Integration:** Built numerous full-stack apps with Django, handling custom API integrations, secure logins, and adapting to existing app workflows. 3. **Preferred Stack:** Prefer Django (Python) for robust, secure API backend development. Also skilled with Firebase Auth. 4. **Cost & Timeline:** Happy to provide a fixed price/timeline after a quick chat to confirm the full scope. 5. **Availability:** Available to start immediately. I'm confident I can deliver a flawless, well-documented backend that integrates perfectly. Let's discuss! Best regards, Nikhil Chandra Roy