Secure Payment Processing Integration

@Microlent

Hello, I am Dr. Rajesh Rolen, PhD in Computer Science & Engineering, with experience of over 20+ years in API Integration, PHP, GraphQL, JavaScript, PostgreSQL, Node.js As a preferred freelancer in the top 1%, I have done 400+ projects here on freelancer.com, I have 4.9 ratings out of 5 on average, which showcases my quality of work and timely delivery. Key Highlights: - Free Hosting Support on the Cloud or any desired platform. - Free 3 months of post-delivery support to ensure that our client doesn’t face any challenges after the launch of the project. - Free Dedicated tester on projects to ensure quality delivery, so clients don’t need to act as a tester. - 10+ Years experience UI/UX team to ensure intuitive UI. Portfolio: https://www.freelancer.com/u/Microlent Please open the chat and send me a message, so we can have a more detailed discussion about the project to give you the project timeline and cost. Thank you for considering my services. I look forward to engaging in a productive conversation and understanding how I can be of assistance in bringing your project to life. Regards Rajesh Rolen

@OutsourceMan

Hello, We can integrate a secure end-to-end payment system into your existing Node.js + React application while keeping sensitive card data entirely within the payment gateway. Our methodology will be: • Review the current React, Node.js and PostgreSQL architecture and select the most suitable gateway based on your merchant setup. • Implement secure client-side tokenization and server-side payment processing. • Handle 3-D Secure, refunds, recurring payments, webhooks and idempotency to prevent duplicate transactions. • Store only required transaction metadata and gateway IDs in PostgreSQL—never raw card details. • Implement clear failure handling, retry logic and consistent UI responses. • Configure separate sandbox/live environments and secure credentials. • Add unit and integration tests for successful, declined, expired-token and timeout scenarios. • Provide clean commits, setup documentation and a walkthrough for production handover. We’ll focus on a reliable, maintainable integration that is ready for your production rollout.

@a4logic

Hello, As an experienced developer with a solid understanding of both JavaScript and PHP, I am well-equipped to tackle your Secure Payment Processing Integration project. I have worked extensively with Node.js and React - your preferred stack - thus offering me valuable skills for this task. Additionally, I am familiar with REST/GraphQL, and crucially, the best practices around PCI-DSS implementation, ensuring the security and confidentiality of sensitive card data - a vital concern in any e-commerce application. My expertise extends beyond merely choosing and integrating payment gateways; it includes the invaluable understanding of idempotency keys, webhooks, and automated testing that simulates edge-case payment scenarios - all of which are significant elements of your project requirements. My long-standing experience has shown me that the level of attention paid to these details can significantly impact handling success, failure scenarios, and user experience. My commitment to clear commit history, concise documentation, and reproducible local setup instructions further ensures smoother handover, even in complex systems like this. Ultimately, I bring 15+ years of experience to the table along with an affinity for undeniably clean code and maintainable software. My dedication to quality work aligned with your set acceptance criteria makes me confident that together we can build a secure payment system that demonstrates immediate Thanks!

@shrec

Hi there, I can integrate the payment flow directly into your existing Node.js and React application, with the gateway handling all sensitive card data while your system receives only the required transaction metadata. I’d set up the server-side payment flow, tokenization, 3-D Secure, refunds, recurring charges where needed, and PostgreSQL transaction records, with clean REST or GraphQL integration on the client side. I’ll also implement webhook verification, idempotency protection, sandbox/live configuration, and clear handling for declined payments, expired tokens, and network failures. I’ll include unit and integration tests for the required edge cases, keep the implementation PCI-conscious, and provide concise documentation plus reproducible local setup instructions. The final flow will ensure gateway and internal admin transaction IDs remain synchronized. Best, Ivane

@starttechno

I’ll connect the React checkout to your chosen gateway through Node.js, keeping card data tokenized at the gateway while persisting matching payment and order IDs in PostgreSQL. The implementation will cover 3-D Secure, idempotency keys, clear decline and retry handling, refunds, recurring charges where applicable, and signed webhooks so the admin panel stays synchronized even after delayed gateway events. In 4 days, I’ll deliver the server routes, client-side payment flow, sandbox/live configuration, webhook processing, and automated coverage for success, declined cards, expired tokens, and network timeouts. I’ll also include concise setup notes, a clean commit history, and a short walkthrough so production rollout is reproducible. Which gateway should I target first: Stripe, PayPal, or Adyen? Muhammad Saad

@installerpoint

Hello, I can integrate secure end-to-end payment processing into your Node.js and React application using Stripe, PayPal, Adyen, or the gateway best suited to your merchant setup. I’ll implement tokenization, 3-D Secure flows, refunds, recurring charges, webhooks, idempotency, PostgreSQL transaction metadata, and clear client/server error handling without exposing raw card data. I’ll also add sandbox-to-live configuration, automated tests for successful, declined, expired-token, and timeout scenarios, matching gateway and admin identifiers, concise documentation, and reproducible setup instructions. As a useful improvement, I recommend a centralized payment service layer so gateway-specific logic remains maintainable and extensible. Check our portfolio, https://www.freelancer.com/u/installerpoint Best Regards, Muhammad Adeel

@nikhilgarg96

Hello Greetings, After reviewing your project description, I feel confident and excited to work on this project for you. But I have some crucial questions to clarify. Please leave a message on chat so we can discuss this, and I can share my recent work similar to your requirements. Thanks for your time! I look forward to hearing from you soon. Best Regards.

@SBITServices

Hi, I will integrate a secure payment processing system into your application by selecting and incorporating a mainstream gateway like Stripe, PayPal, or Adyen. I will handle the server-side logic, client-side calls, tokenization, 3-D Secure flows, refunds, and recurring charges. My expertise in Node.js, React, REST/GraphQL, PCI-DSS best practices, webhooks, idempotency keys, and automated test scripts will ensure a seamless integration. Let's discuss further. Regards, Sai Bhaskar

@gutibs

Hi! This is bread-and-butter work for us — and the acceptance criteria you've laid out tell me you already know what a solid integration looks like, which makes scoping this straightforward. One thing I need to know: which gateway are you leaning toward? Stripe, PayPal, and Adyen have meaningfully different webhook models and 3-D Secure flows, and if you already have an active merchant account with one of them, that's where we'd build — no point developing against a sandbox you'd have to migrate away from later. On how we'd approach it: the payment logic would live in a dedicated module within your Node.js layer, isolated from the rest of your business logic so the PCI-DSS surface stays narrow. Tokenisation happens on the gateway's side entirely; raw card data never touches your server or PostgreSQL schema. What does get stored is the transaction metadata — intent IDs, status, idempotency keys, timestamps — structured so your admin panel and the gateway dashboard always reconcile cleanly. Webhook handling includes signature verification and idempotent processing so retried events don't produce duplicate records. On the React side, we'd use the gateway's hosted fields so the UI feels native without you ever owning sensitive input. The test suite would cover the four scenarios you listed — happy path, decline, expired token, network timeout — all run against the sandbox before anything touches live credentials. Gustavo & the DoTheCode team

@seefattechnologi

Hi, I will integrate secure, end-to-end payments into your Node.js + React app so customers can pay without ever leaving your platform. I’ve done this with Stripe, PayPal, and Adyen—handling tokenization, 3-D Secure, refunds, recurring charges, webhooks, idempotency, and clean sandbox-to-live rollouts. What you’ll get: Seamless payment flow from UI to PostgreSQL, with no raw card data ever touching your servers. Clear error messaging, retry logic, and matching transaction IDs in both gateway and admin panel. Unit/integration tests covering success, declines, expired tokens, and timeouts. Clean commits, concise docs, and a quick walkthrough for handover. If you share your preferred gateway and current order flow, I can outline the exact integration steps and timeline.

@Rekhathakur

Hello, With a decade of experience in web development and deep expertise in API Integration, JavaScript, and Payment Processing, WellSpring Infotech is the right choice for your Secure Payment Processing Integration project. We understand the significance of seamless end-to-end payments, keeping your customers within the platform while enhancing their financial transaction experience. Our skills in Node.js and React, along with REST/GraphQL understanding, make us perfectly suited to wire up the server-side logic and provide clean client-side calling for tokenization, 3-D Secure flows, refunds and recurring charges where relevant. We understand that security is paramount for any payment system; utilizing our extensive knowledge of PCI-DSS best practices, we can assure you that no raw PAN data will be stored or logged. Additionally, my familiarity with mainstream gateway APIs like Stripe, PayPal and Adyen enables me to select an appropriate one tailored to your needs. Our experience includes working with webhooks, idempotency keys, sandbox vs. live environment rollouts and writing automated test scripts. I can design test scenarios that simulate edge-case payments ensuring full coverage of happy path as well as declined card, expired token or network timeout cases. Moreover, we value clear commit history, concise documentation and will ensure reproducible local setup instructions. Thank you

@crtvecode

You're looking to integrate a payment processing solution that not only works smoothly but also adheres to PCI-DSS standards. I can help with that. I'll focus on integrating your chosen gateway—be it Stripe, PayPal, or Adyen—making sure that all sensitive card data remains secure and that no raw PAN is logged, those details are really important. I’ll implement the server-side logic in Node.js, create clean client-side calls, and set up the necessary transaction metadata storage in PostgreSQL. And I can complete the work first, so you can test everything before making any payment or awarding the project. This way, you only proceed once you're satisfied with the results, which is the goal here. I'm ready to start immediately for $62. Let’s get your payment integration up and running, I can go ahead and make sure it’s all smooth and efficient. Rajavel Node.js, React, and payment processing expert.

@rehmatclick

HI, I hope this message finds you well. I am Muhammad Ghaffar, an experienced and verified web developer on Freelancer.com with over 8 years of professional freelancing experience. You can verify my credentials and past work by visiting my profile: Freelancer Profile. I have thoroughly reviewed your project details and am confident that I can deliver exactly what you're looking for. However, I do have a few questions to ensure that I fully understand your requirements and can provide the best solution. Could you please message me to discuss these details further? Why Choose Me: 8+ Years of Experience: Extensive background in WordPress development. Verified on Freelancer.com: Proven track record of delivering high-quality work. Portfolio of Successful Projects: Omnes Influencers Linee Kaci Healthee Craft Shades I am dedicated to delivering top-notch services and would love to assist you with your project. Please feel free to get in touch so we can discuss further details. Looking forward to your response. Best Regards, Muhammad Ghaffar Freelancer Profile

@CANWS

Hi, ⚡ Secure Payment Gateway Integration — Node.js · React · PostgreSQL I can integrate Stripe/PayPal/Adyen into your existing application with secure tokenization, 3-D Secure, refunds, recurring payments, webhooks and idempotency handling. I’ll also cover gateway-to-database transaction syncing, declined/timeout retry flows, sandbox → live rollout, and automated payment tests without storing sensitive card data. You’ll receive clean commits, concise documentation, local setup instructions and a final walkthrough. I can start immediately and work directly with your existing Node.js/React codebase. Thanks

@denisSolution

Hi, I'm Denis, a full-stack developer specializing in payment processing systems. I've integrated Stripe, PayPal, and similar gateways into production applications, handling tokenization, webhooks, and complete transaction lifecycles. I understand your needs: a secure bridge between React frontend and Node.js backend that connects to your payment gateway without exposing raw card data. The gateway handles tokenization, your server orchestrates the flow, and PostgreSQL tracks transactions. I've built similar systems where the real challenge is structuring code so webhooks stay reliable, idempotency keys prevent duplicate charges, and your admin panel reflects gateway data accurately. I've created test suites simulating declined cards, expired tokens, and network failures. My approach: 1. Review your architecture and select the best payment gateway 2. Build server-side logic for payment intent creation, tokenization, 3D Secure, and webhook processing 3. Create clean React components that submit payments securely 4. Wire everything into PostgreSQL with proper transaction tracking 5. Add comprehensive tests for edge cases 6. Set up sandbox testing before going live The critical technical consideration is webhook reliability and idempotency. If webhooks retry or network issues cause duplicate requests, your system must recognize them and prevent duplicate charges. I'll implement idempotency keys and database constraints to safeguard against this. One realistic risk: unclear

@marjanahmed13

Hi! My name is Marjan and I'm here to offer you my services as a skilled applicant with over a decade of experience working on Freelancer.com. I believe I am the best fit candidate for this project due to my extensive experience; I would like to have a discussion to get to know that we both are on the same page. Once the scope will be locked, I will start working on it right away.

@Web1devloper

With over 8 years of full-stack development experience, specializing in API integration and with considerable GraphQL and Node.js expertise, I am uniquely positioned to handle your project with efficiency and precision. I have a proven track record of successfully taking client ideas and turning them into fully-functional solutions just like the one you need in your project. Regarding your desire to ensure a secure payment processing system, I am well versed with both PCI-DSS best practices and the payment gateways APIs such as Stripe, PayPal, and Adyen. I am also experienced in working with webhooks, idempotency keys, sandbox/live environment rollouts--essential for building a robust payment system. My proficiency with REST and GraphQL would enable me to wire-up the client-side calls flawlessly while keeping the sensitive card data completely separate from your application in compliance with industry standard security guidelines. Additionally, my exposure to PostgreSQL as database solution during my career makes me aptly equipped to handle storage of encrypted transaction metadata safely. To ensure a smooth transition without compromising on quality, I also assure you that I provide clear commit history and concise documentation along with reproducible local setup instructions. Lastly, my dexterity with automated test scripts is worth mentioning as it facilitates detecting and simulating potential edge cases before they become issues---------

@vikrant12112

Hi , I have gone through your project, Secure Payment Processing Integration, and I am ready to start working as soon as you confirm. I offer best quality and highest performance at a reasonable price, with on-time delivery. I’m well-versed in PHP, Python, CSS, HTML, JavaScript, jQuery, Bootstrap, Angular, AJAX, Laravel, WordPress, API Integration, Node.js, Payment Processing, PostgreSQL, PHP, JavaScript, GraphQL and Cold Fusion. I’d love to discuss the project further to ensure we’re aligned on the scope, timeline, and deliverables. Please let me know a convenient time for us to connect, and I’ll be happy to accommodate. Thanks

@codefusion53

Hi, I understand you're looking to implement secure end-to-end payment processing in your Node.js and React application. I have extensive experience integrating payment gateways like Stripe and PayPal, ensuring PCI-DSS compliance, and handling webhook notifications. My approach involves setting up the server-side logic to securely process transactions, managing tokenization and 3-D Secure flows, and creating clean client-side calls for a seamless user experience. I will ensure that sensitive data remains with the gateway, and that transactions are accurately logged with matching IDs in your dashboard and internal database. I also prioritize writing clear commit histories, detailed documentation, and reproducible setup instructions. I am confident I can deliver a robust solution that handles edge cases such as declined cards or network timeouts, with proper testing and rollback strategies. Once integrated, I will assist with a brief walkthrough to transfer knowledge effectively and ensure your team can maintain the system moving forward. Best, Justin