Fullstack Developer (Flutter + Node.js) – Debug App (AI-Assisted, Max 62h) -- 2

@Microlent

Hello! I read through your requirement and it’s an interesting debugging project. Stabilizing a Flutter frontend with a Node.js/PHP backend while fixing WebSocket, wallet persistence, and crypto API issues is something I can help with. For projects like this, the focus will be on systematic debugging, verifying every fix, and ensuring the application becomes stable and auditable within the defined time limit. The work can include: • Fixing WebSocket chat reconnection logic, synchronization, and error handling • Resolving wallet persistence issues so the wallet remains stored after app restart • Correcting balance update delays to refresh automatically without manual reload • Fixing transaction history endpoints and adding proper logging • Implementing the QR scanner flow for sending funds • Debugging and activating crypto backend APIs including register, wallet creation, restore, tokens, and notifications • Providing clear documentation and test validation for each fix All fixes will be manually tested, documented, and verified so the results are stable and auditable within the 62-hour scope. Quick question: do you already have a staging environment or test wallet environment where these fixes should be validated before deployment? Best regards, Jasmin

@tangramua

Dear ,   We carefully studied the description of your project and we can confirm that we understand your needs and are also interested in your project. Our team has the necessary resources to start your project as soon as possible and complete it in a very short time.   We are 25 years in this business and our technical specialists have strong experience in PHP, Debugging, Node.js, Socket IO, AngularJS, Full Stack Development, Flutter, API Development and other technologies relevant to your project.   Please, review our profile https://www.freelancer.com/u/tangramua where you can find detailed information about our company, our portfolio, and the client's recent reviews.   Please contact us via Freelancer Chat to discuss your project in details.   Best regards, Sales department Tangram Canada Inc.     

@shrec

Hello, I can help debug and stabilize your Flutter + Node.js/PHP application, focusing on resolving the WebSocket chat issues, wallet persistence problems, delayed balance updates, transaction history API errors, QR scanner implementation, and inactive crypto backend APIs. I work as an individual full-stack developer, and I will manually verify each fix, perform thorough testing, and provide clear documentation so all changes remain auditable within your 62-hour limit. My approach includes reviewing the WebSocket reconnection logic, backend API endpoints, local wallet storage, and transaction logging to ensure the system becomes stable and production-ready. I’m comfortable working under milestone-based verification, and I’ll ensure every fix is properly tested before submission.

@webperfection123

Hi, I have extensive experience in both Flutter for mobile development and Node.js for backend services. I can tackle issues like WebSocket reconnections and ensure wallet persistence. It would take me around 50-60 hours to stabilize these core features, including thorough testing and documentation for each fix. I’m comfortable working within the fixed-price milestone structure and will ensure all solutions are verifiable and properly tested before you sign off. Looking forward to your response! Best Regards, Priyanka

@divumanocha

Hello, I came across your project and found it truly interesting. With over eight years of hands-on experience in this field, I have successfully delivered high-quality solutions to clients worldwide. My dedication to excellence is reflected in the 180+ positive reviews from satisfied clients. I’d love to bring this expertise to your project and ensure outstanding results. However, I do have a few important points I’d like to clarify to align perfectly with your vision. Let’s connect via chat so I can share relevant examples of my past work. I look forward to hearing from you. Best Regards, Divu.

@GintarasZelvys

Hi. As Flutter Expert, I am very interested in your project. I am very familiar with Flutter, Node.js and PHP. I have mobile and backend skills with 8+ years. I wish to work for you. Thanks for attention.

@Julian29

Hello, I can help you debug and stabilize your app, addressing the core issues you've outlined. With experience in both Flutter for the front-end and Node.js/PHP for the back-end, I can provide the following solutions: Scope of Work: WebSocket/Chat Fixes: Implement and test reconnection logic, synchronization, and robust error handling to ensure reliable chat functionality. Wallet Persistence: Debug and fix the issue causing the wallet to be forgotten on app restart. Balance Update Delay: Address the refresh delay and ensure balance updates happen automatically without requiring manual refresh. Transaction History: Correct API endpoints for transaction history and ensure logs are properly recorded and displayed. QR Scanner for Sending Funds: Implement the QR scanner functionality, ensuring smooth user experience when sending funds. Crypto Backend API Fixes: Investigate and fix issues with backend APIs related to user registration, token creation, restoration, and notifications. I will approach the project with thorough testing and a focus on clear, maintainable code, ensuring that the app is stable and ready for further use.

@AhteshamAK

Hello, I hope you're doing well. I can help you debug and stabilize your Flutter and Node.js/PHP-based app with a clear, thorough, and audit-ready approach. Your key issues, WebSocket reconnection, wallet persistence, delayed balance updates, incorrect transaction endpoints, missing QR scanner, and inactive crypto APIs, align perfectly with my experience in real-time systems and secure wallet flows. As an individual fullstack developer, I’ll meticulously verify each fix, perform manual testing, and provide clear documentation as required. My approach ensures your app becomes stable, predictable, and fully auditable within your 62-hour cap. I work efficiently, prioritize reliability, and maintain transparent progress updates. I'm ready to begin immediately and deliver a stable, production-ready build. Best regards, Ahtesham

@DeveloperStation

Hi, I’ve developed multiple web and mobile apps with integrated chat features, including a fully functional WhatsApp clone. I understand the importance of reliable WebSocket connections and have implemented reconnection logic, error handling, and message syncing in my previous projects. As a full-stack developer with 12 years of experience, I’ve worked extensively with Node.js, PHP, and modern front-end frameworks like Vue.js and React.js. I’m also well-versed in CI/CD pipelines and server management, ensuring that your app is always secure and up-to-date. Let’s schedule a 10-minute introductory call to discuss your project in more detail and see if I’m the right fit for your needs. I’m eager to learn more about your exciting project. Best regards, Adil

@royalwebraisers

Hi, As per my understanding: Debug/stabilize Flutter/Node.js app (max 62h)—fix WebSocket chat reconnect/sync, wallet persistence, balance delays, transaction APIs, QR scanner, crypto backend endpoints. Implementation approach: - Fix WebSocket reconnect w/ exponential backoff, wallet persistence via secure storage. - Correct API endpoints, add transaction logging, QR scanner integration. - Full test suite + docs; complete audit-ready in 40 hours. I will share my portfolio on your first message. Queries: Repo access? Priority bugs? Current error logs? Best Regards

@khurshid040462

Hi, I see you're looking for a fullstack developer to debug your app, specifically addressing critical areas like WebSocket handling and wallet persistence. With over 4 years of experience in both Flutter and Node.js development, I have successfully resolved similar issues in past projects. To tackle your core issues, I will start by implementing a robust reconnection logic for WebSocket and ensuring proper error handling. I recommend maintaining comprehensive documentation throughout to facilitate smoother audits. In a previous role, I addressed a crypto wallet application's transaction history discrepancies by revising API endpoints, resulting in a significant boost in stability. I can commit to a maximum of 50 hours to ensure thorough testing and auditing. What specific metrics or benchmarks are you using to verify the fixes during your audits? Regards, Khurshid Ahmed

@mahig47

Hello! As per your project post, you’re looking to debug and stabilize your existing mobile application built with a Flutter frontend and a Node.js or PHP backend. The goal is to identify and resolve critical functional issues across the app, ensuring stable communication with backend services, reliable wallet persistence, accurate balance updates, and fully operational crypto related features. My focus will be on delivering a thoroughly debugged and stabilized application, featuring: WebSocket chat improvements including reconnection logic, synchronization and proper error handling, wallet persistence fixes so the wallet remains securely stored across app restarts, corrected balance update logic that refreshes automatically without requiring manual reload, repair of transaction history with correct API endpoints and proper logging, integration of the missing QR scanner for sending funds, and activation. I specialize in building and maintaining cross platform mobile applications using Flutter with scalable backend systems built in Node.js and PHP. My approach focuses on systematic debugging, secure API integration, and ensuring that every fix is thoroughly tested so the application runs reliably in production environments. Let’s connect to review the current codebase and determine the best debugging strategy to stabilize the WebSocket communication, wallet logic, and crypto backend integrations. Best regards, Nikita Gupta.

@denisSolution

Hello, client I'm Denis Redzepovic, an experienced developer skilled in API Development, Socket IO, Full Stack Development, PHP, Flutter, AngularJS, Debugging and Node.js. I specialize in building high-performance, scalable, and visually appealing applications that deliver smooth functionality and a seamless user experience. Whether you need full app development, UI/UX improvements, API integrations, or performance optimizations, I can provide a tailored solution that fits your needs. I focus on clean, maintainable code with responsive UI, smooth animations, robust state management, and seamless API integration. My approach ensures scalable architecture and pixel-perfect design, delivering consistent performance across Android and iOS platforms. With cross-platform efficiency and attention to detail, I’m confident I can add strong value to your project. I’d love to discuss your requirements and find the best approach to bring your vision to life. Thanks, Denis

@Feriver

Hello, I understand you need a fullstack developer to debug and stabilize your Flutter frontend with a Node.js/PHP backend. I can address WebSocket reconnections, chat sync, error handling, wallet persistence, balance updates, transaction history endpoints, QR scanner functionality, and inactive crypto backend APIs. All fixes will be manually verified, fully tested, and auditable. I will ensure clear documentation of all changes, include test results for verification, and maintain modular, readable code for future maintenance. The focus is on reliability, correctness, and seamless user experience across all core app features. Deliverables include a stabilized app, fully tested fixes for WebSocket, wallet, balance, transaction history, QR scanning, and backend API issues, plus documentation suitable for audit and verification within the 62-hour limit. Client Clarification Questions: 1. Are there preferred testing devices or environments for verifying WebSocket and QR scanner fixes? 2. Should the backend API fixes follow existing structures or is refactoring allowed for stability? Thanks, Asif

@hireageek

Hi there! I’m excited about the opportunity to debug and stabilize your app. As a top freelancer from California with a proven track record of success and numerous five-star reviews, I specialize in Flutter and Node.js development. I'm confident I can tackle the core issues you’ve outlined, including the WebSocket sync logic, wallet persistence problems, and the performance of your crypto backend APIs. Understanding the importance of meticulous verification, I will ensure that every fix is thoroughly tested and documented, leaving no room for error. With a maximum of 62 hours dedicated to this project, I am prepared to deliver high-quality results efficiently. I’d love to chat about your specific needs and answer any questions you might have before we proceed. Could you clarify which specific features or fixes are the highest priority for you?

@solutionsplayers

As an experienced PHP developer with a focus on Laravel, I ensure robust and scalable backends for your applications, which directly addresses the issues you raised in your project description. My main goal is to build high-performing applications while creating a smooth and user-friendly experience, allowing your users to enjoy uninterrupted services. My expertise in Flutter means that I can also tackle any frontend issues with incredible ease, ensuring not only are the problems fixed, but that the fixes adhere to verified standards. Rest assured, all my solutions undergo rigorous testing and thorough auditing before release. To complement this meticulous approach, I offer clear documentation which makes maintenance easier for you going forward. In addition to my programming and debugging capabilities, an aspect that clients highly value about working with me is my commitment to thoroughness. To me, no issue is too big or too small, and I'll dedicate myself completely towards finding a solution. You can count on me to respond promptly to any concerns and provide regular updates on progress. Choose me for this project and together we'll create a stable and reliable application that meets all your exacting standards.

@arbu1499

Hi! I’m an experienced fullstack developer with Flutter frontend and Node.js/PHP backend expertise. I can debug and stabilize your app within your 62-hour limit, fully testing and documenting fixes for WebSocket chat, wallet persistence, balance updates, transaction history, QR scanner, and crypto backend APIs. All changes will be manually verified and auditable, ensuring smooth, reliable operation. Looking forward for your positive response in the chatbox. Best Regards, Arbaz M

@rbtech1984

Hello There!!! ★★★★ ( Debug & Stabilize Flutter + Node.js Crypto App ) ★★★★ I understand you need a fullstack developer to debug and stabilize your Flutter frontend with Node.js/PHP backend, covering WebSocket chat, wallet persistence, balance updates, transaction history, QR scanner, and crypto API issues. All fixes must be verified, tested, and documented within 62 hours. ⚜ WebSocket reconnection, sync, and error handling ⚜ Wallet persistence fixes on app restart ⚜ Balance update and refresh optimization ⚜ Transaction history correction and logging ⚜ QR scanner integration for sending funds ⚜ Crypto backend API activation and debugging ⚜ Clear documentation and test verification I have hands-on experience debugging fullstack Flutter apps, integrating Node.js backends, and ensuring reliable wallet and crypto functionality. I’ll provide fully tested, auditable fixes with clear documentation. Excited to help stabilize your app quickly and efficiently. Warm Regards, Farhin B.

@Sohail748

Hii there, I’m offering a 30 percent discount for this project and would be glad to assist you as a full-stack developer (Flutter + Node.js) to debug and optimize your AI-assisted app. With experience in Flutter development, Node.js backend, and AI integration, I can identify and fix issues while improving the app’s performance and stability within your 62-hour timeframe. My approach will focus on reviewing the codebase, diagnosing bugs or performance bottlenecks, implementing necessary fixes, and ensuring seamless communication between the Flutter frontend and Node.js backend. I will also test all features thoroughly to confirm the app functions reliably and integrates smoothly with any AI services. As a dedicated freelancer, I prioritize attention to detail, clear communication, and delivering high-quality, maintainable solutions. I am confident that I can debug and enhance your AI-assisted app efficiently and meet your project requirements within the specified hours. Kind regards, Sohail Jamil