Senior Fintech / Full-Stack Developer — Marketplace Monetization, Payments & Payouts

@Microlent

Hi, Your project needs more than a standard payment integration—the key is building a **secure, auditable financial architecture** that can handle subscriptions, pay-per-use, referrals, commissions, withdrawals, refunds, and multiple PSPs without affecting the existing marketplace. I can work with your existing **React, NestJS/Node.js, MongoDB and REST API** stack and extend it without unnecessary rewrites. My focus would be on: Configurable subscription and pay-per-use billing Provider-independent payment architecture Proper ledger instead of a simple wallet balance Separate credits, pending/available earnings and withdrawable funds Referral/agent commissions with reversal support Idempotent webhooks and duplicate-payment protection Withdrawals, payouts, refunds and reconciliation RBAC, audit logs and financial security Multi-country and multi-currency readiness I understand the importance of keeping financial history traceable and handling refunds/chargebacks through reversals rather than modifying or deleting transactions. I can also help evaluate suitable **PSP, payout and KYC/KYB providers** for your target African markets and design the architecture so additional countries and providers can be added later. I’d suggest starting with a review of the existing codebase, followed by the financial architecture and implementation milestones. Let’s connect and discuss the existing platform and next phase.

@gangradeankit

As an experienced full-stack developer specializing in fintech systems and AWS utilization, I offer a unique blend of skills to elevate your marketplace's monetization mechanisms. My prior projects encompassed similar responsibilities of creating a sophisticated financial layer for robust applications, aligned perfectly with the objectives described here. I understand that your prime concern is the expansion of the existing platform without disrupting its current functions, and this is something I specialize in. I am adept at extending architectures rather than rewriting them unnecessarily. This would ensure that your marketplace can evolve smoothly into a more salable SaaS/subscriptions model while incorporating advanced features like pay-per-view, pay-per-download, and referral rewards seamlessly. Moreover, my proficiency with provider-based payments will enable me to integrate multiple currencies and payment providers effortlessly. This will allow necessary scalability tailored to different countries without the need for fundamental reconstruction. Also, noteworthy is my expertise in maintaining an efficient ledger/transaction model—a crucial aspect for escrow, KYC/KYB—separating platform rewards from withdrawable earnings to ensure utmost clarity. Choosing me guarantees not just a skilled developer but an insightful teammate dedicated to bringing your vision to life in the most practical way possible.

@Hrolgar

The decision to settle before any code gets written is whether you build one payment core every PSP and mobile money rail plugs into, or let each country bolt straight onto the app and end up with several different definitions of what a payout actually is. You've already ruled out a walletBalance field, rightly. I'd build this as an append-only ledger, payment into revenue into attribution into commission into payout, every event traceable back to its source, with the PSP and KYC vendor behind a provider interface so Nigeria or Kenya can run a different rail without touching core financial logic. Subscriptions, pay-as-you-go and pay-per-view become entry types into that same ledger instead of separate billing systems, which is what keeps referral and agent commission math honest once money moves through more than one country. The number below is built off the brief as posted, the real variable is how many PSPs and mobile money rails need to be live at launch versus phased in after the ledger's proven. M1: ledger core plus one PSP end to end, 200,000 INR, 15d M2: subscriptions, pay-as-you-go, pay-per-view billing, 220,000 INR, 15d M3: referral and agent commission attribution, 180,000 INR, 12d M4: withdrawal/payout lifecycle, second PSP, mobile money payout, 220,000 INR, 18d M5: KYC vendor abstraction, reconciliation, hardening, 180,000 INR, 15d First milestone gets you a working ledger and one real payment flow, worth proving before locking the rest of the 75 days.

@Walkingdreams

With over 13 years leading several tech projects similar to yours, I'm confident I can bring immense value to your platform. As the leader of Walking Dreamz Technologies, my team and I have extensive experience in MERN, API integrations, and fintech solutions. We don't just deliver work, we build long-lasting partnerships through clear communication, streamlined code, and predictable delivery. In terms of your project, our team understands the gravity of extending an existing platform without breaking current functionalities. We'll review your React/NestJS/MongoDB application ecosystem and extend the architecture rather than unnecessarily rewriting it. Our aim is to build a robust and configurable monetization engine that supports various revenue models from SaaS/subscriptions to pay-as-you-go services and more. This includes a sophisticated ledger system that properly separates platform credits/rewards from withdrawable earnings ensuring enhanced security and traceability. When it comes to payment infrastructure, we appreciate the need for different Payment Service Providers (PSPs) based on country preferences without rebuilding core financial logic. Thus, we will implement robust provider-based payments that align with your specific needs whist being currency-aware. Moreover, when implementing the auditable financial ledger system, we will ensure every event remains traceable to its originating transaction, separating purchased/promotional credit from withdrawable cash.

@mrresearcher99

Hello, I have 10 years of experience developing scalable SaaS, marketplace, CRM and fintech-oriented platforms using Node.js, React.js, REST APIs, MongoDB, PostgreSQL and cloud infrastructure. I can extend your existing NestJS marketplace without disrupting current functionality. I would build a provider-agnostic monetization layer separating products, pricing, subscriptions, entitlements and usage billing from individual modules. A double-entry-style financial ledger would separately track platform credits, rewards, pending earnings, available earnings, reserves, payouts and reversals. Webhook idempotency, immutable transactions, audit trails and reconciliation would prevent duplicate credits and maintain accurate commission reversals after refunds or chargebacks. I’d be glad to discuss the architecture and milestone plan. Best regards

@ashinnd84

Hello there, we are a team of senior Python, AI Automation Full Stack Web and Mobile App Developers. Please, send me a message to discuss the work. Thanks Ash.

@AZTURK1

Hi there, I reviewed your React, NestJS, and MongoDB setup. Building an immutable ledger that strictly separates promotional credits from withdrawable partner balances—backed by database transactions and webhook signature validation—is the right way to protect revenue, especially when handling multi-currency African rails. What I'll do: ✅ Build an auditable ledger and monetization engine in NestJS using MongoDB session transactions to handle subscriptions, pay-per-view, and revenue-sharing. ✅ Implement an abstracted payment and payout provider layer with strict idempotency, signature verification, and state tracking (pending, available, reserved, paid). ✅ Run end-to-end sandbox simulations for edge-case refunds, dispute reversals, and failed webhooks on staging before touching live traffic to ensure zero disruption. ✅ NestJS & Node.js architecture ✅ MongoDB transaction & ledger modeling ✅ Payment gateway & payout rails integration ✅ API security & idempotency handling ✅ Microsoft® Certified: MCSA | MCSE | MCT ✅ 300+ projects delivered, 280+ five-star reviews Why me: Fast responses, clear updates, and unlimited revisions until all financial workflows are rock solid. Do you already have active merchant accounts with regional aggregators like Flutterwave or Ozow, or would you like the provider abstraction designed around a specific initial gateway? I can deliver in 7 days for 680000 INR and can start right now.

@TechizeBuilder

Dear Client, I read "Senior Fintech / Full-Stack Developer — Marketplace Monetization, Payments & Payouts" carefully and understand you are looking for a full-stack developer who can handle both application development and AI integration. I have experience with Amazon Web Services, Node.js, React.js, Payment Gateway Integration, MongoDB and can work across the complete stack — frontend, backend, APIs, databases, authentication, third-party integrations and AI features. I can build scalable applications using modern technologies while keeping the codebase maintainable and production-ready. A few quick questions: Which AI models/APIs are you currently planning to use? Is there an existing application/codebase, or will the project be built from scratch? Thanks & Regards, Deepak

@Azursol

Hello, I understand the complexities involved in extending your existing multi-module marketplace for SaaS/subscriptions, pay-as-you-go monetization, payments, referrals, and financial administration without disrupting current functionality. With over a decade of experience in Software Architecture, Amazon Web Services, Node.js, React.js, Payment Gateway Integration, MongoDB, API Integration, and FinTech, I have successfully delivered similar projects. My approach involves reviewing the current system thoroughly, implementing a configurable monetization engine, integrating a provider-based payment infrastructure, and establishing a robust financial ledger to ensure traceability and security. I recommend a provider abstraction for payments and suggest utilizing established KYC providers for future readiness. Let's discuss how my expertise can add value to your project further. Best regards,

@ssquare489

The key here is a ledger-first financial layer, not a single walletBalance or payment logic scattered across marketplace modules. I’d extend the existing NestJS/MongoDB architecture with provider-neutral billing, entitlement, attribution, commission, payout and reconciliation services. Subscriptions, PAYG and pay-per-use would use configurable Product → Price → Billing Rule → Entitlement definitions. Ledger accounts would separately track purchased credits, rewards, pending earnings, available earnings, reserved payouts and paid earnings. Every provider webhook would use signature validation, provider event IDs, idempotency keys and atomic processing. Refunds/chargebacks would create reversal entries against the originating revenue and commission records, never delete history. For the initial African markets, I’d evaluate Flutterwave/dLocal plus regional PSP fallbacks, with Sumsub for KYC/KYB. I’d use PSPs now rather than BaaS because you do not need unnecessary custody or banking infrastructure. Country/provider adapters would allow new currencies and rails without changing core ledger logic. Closest relevant work: Dealbridge, a multi-sided platform where we built provider/consumer/admin workflows with configurable commission tracking across service transactions. I have personally integrated Stripe and Razorpay; I would not claim KYC integrations I have not implemented.

@KasjanovaEste

Hi there, the main goal is to extend your existing React/NestJS marketplace with a proper fintech layer covering monetization, payments, attribution, ledger, commissions and controlled payouts without disrupting current modules. I’d first audit the codebase, then build provider-agnostic billing and financial services around immutable double-entry-style ledger events, separating credits, rewards, pending earnings and withdrawable balances. I think you’re aiming for a marketplace financial foundation that can grow across African markets, so I’d isolate PSP, payout and KYC adapters and handle webhooks with signatures, idempotency, reconciliation and reversal entries. For initial markets I’d evaluate Flutterwave, Paystack and dLocal by country, with KYC/payout availability verified before integration. Seller settlement and escrow can later extend the same ledger and settlement model. M1: Audit + architecture, 1.5 weeks, ₹200,000 M2: Billing + ledger + payments, 3 weeks, ₹350,000 M3: Commissions + payouts + QA, 2.5 weeks, ₹250,000 Total: ₹800,000. Looking forward to working with you.

@dammak13

Dear Employer, We are Sumay Infotech, Ahmedabad, with 8+ years of experience in web and app development, including fintech and payment-driven platforms. Your requirement strongly matches our expertise. We can extend your existing React + NestJS + MongoDB marketplace with a robust financial architecture covering subscriptions, pay-per-use, payments, referrals, commissions, ledger, withdrawals, payouts, refunds and reconciliation—without disrupting existing modules. We understand this is more than a payment gateway integration. We’ll implement idempotent webhooks, auditable ledger entries, pending/available earnings, commission reversals and provider-independent architecture, keeping the platform ready for multi-country PSPs, KYC/KYB, seller settlement and future escrow. We can review your existing codebase, propose the architecture, milestones, timeline and fixed-price estimate, and we’re open to discussing/negotiating commercials. Let’s connect for a quick technical discussion. Share the existing architecture/codebase and we can take the next step immediately. Best Regards, Sumay Infotech

@PrateekP3003

For the African PSP mix - are you leaning Flutterwave/Paystack for cards plus mobile money rails, and dLocal for cross-border payouts, or is that still open? That choice drives the provider abstraction. On billing: I'd keep the monetization engine module-agnostic. Each paid thing (subscription, PPV, per-download, featured) registers a product+price config, and a central entitlement/billing service resolves it - so no billing logic leaks into marketplace modules. For the ledger I'd use double-entry journal entries per event, with distinct account types (platform credit, promo/reward, pending earning, available, reserved, paid) so promo credits never turn into withdrawable cash. Webhook idempotency via provider event ID + a unique constraint before any credit posts. I've built a Node marketplace with commission tracking and payout lifecycle before. What's the current NestJS repo state - is there any wallet code already I'd need to migrate? - Prateek

@monicasynthesis

Hello, I can extend your existing React/NestJS/MongoDB marketplace with a secure financial architecture without rebuilding the platform. I have 5+ years of experience with Node.js, NestJS, MongoDB, payment APIs, subscriptions, webhooks and scalable backend systems. I will handle: • Subscription, pay-as-you-go and paid-content monetization • Provider-based payment architecture with webhooks and idempotency • Auditable ledger separating credits, rewards, pending and withdrawable earnings • Referral/commission and agent payout systems • Refunds, chargebacks, reversals and reconciliation • KYC/KYB-ready payout architecture and RBAC/admin controls • Multi-country, multi-currency and future PSP support For African markets, I can evaluate providers such as Flutterwave, Paystack, dLocal and relevant local payment/mobile-money providers based on country availability. Warm Regards, Monica Bhatia

@rohitpatidar001

Hi, I’m a **Senior Full-Stack Developer with 11+ years of experience** in React, Node.js/NestJS, MongoDB, REST APIs, financial/compliance systems, authentication/RBAC, cloud and third-party integrations. Your marketplace monetization project is a strong match for my backend and architecture experience. I can extend the existing platform without unnecessary rewrites and build: * Subscription, pay-per-use and paid-content monetization * Provider-agnostic payment integration and secure webhooks * Idempotent payment processing and duplicate protection * Proper immutable financial ledger instead of a simple wallet balance * Referral/agent commission and revenue-sharing workflows * Pending → Available → Withdrawal → Payout lifecycle * Refund/chargeback reversals and reconciliation * RBAC, audit logging and financial admin controls * Multi-currency and multi-country provider architecture I would keep PSP-specific logic behind a provider abstraction so providers such as **Flutterwave, Paystack, dLocal or regional providers** can be added without changing the core financial system. I have strong experience with API integrations and financial/compliance-oriented enterprise systems. I would be transparent that I have not personally integrated every PSP/KYC provider listed, but I have the backend architecture and integration experience required to implement the provider layer correctly. I’m available to start immediately.

@Mayanks010

Hi, Thanks for sharing your project. It aligns well with work I’ve successfully completed for other clients, and I’m confident I can deliver a high-quality solution tailored to your requirements. Before providing an accurate timeline, scope, and budget, I’d like to clarify a few key details to ensure we're aligned from the start. Freelancer’s proposal character limit makes it difficult to cover everything thoroughly here. If you're available, let's connect via chat. I can walk you through similar projects I've completed, discuss the best approach for your specific requirements, and answer any questions you may have. Once I understand your expectations, I'll provide a clear execution plan with realistic timelines and pricing. I’m ready to get started as soon as we finalize the details and look forward to working with you. Best regards, Mayank Sahu

@Rajoriadares

Hello Client, Hope you are great!!! I read you job description you are looking for web developer. I have sound of 15 years exp in wordpress, PHP, CI, Laravel, Drupal, Joomla and developed 145+ websites with good design. We are using the MVC model for security of website as well as develop three layer security in website and website is high skilled code follow all standards of development. I have been worked on many domain like ecommerce, Martrimony, Hotel Booking, Social, Healthcare, and Sport etc. I provide new vision for website and am always available for your support(24*6) . I hope you will be give positive response. Thanks

@indreshpnk

Hello, I understand you need to extend an existing React/NestJS/MongoDB marketplace with a secure monetization and financial architecture covering subscriptions, pay-per-use payments, referrals, commissions, ledger management, withdrawals, payouts, refunds, and reconciliation. The goal is to build an auditable financial layer without disrupting the existing platform. Here’s what I can provide: • Configurable billing engine for subscriptions, usage-based services, paid content, entitlements, and multi-currency pricing • Provider-agnostic payment architecture with secure webhooks, idempotency, refunds, reversals, and reconciliation • Double-entry-style financial ledger separating platform credits, pending/available earnings, reserved payouts, and paid earnings I bring over 4+ years of full-stack development experience with React, Node.js, Django, REST APIs, MongoDB, AWS, authentication, RBAC, and transaction-based application workflows. I focus on scalable architecture, security, API reliability, and maintainable financial workflows. Just to clarify a few things: • Which PSPs are currently integrated, and is the existing financial data model already in production? • Would you prefer the initial architecture to prioritize regional PSPs such as Flutterwave/Paystack/dLocal or a multi-provider abstraction from day one? Please come to the chat box to discus

@waldemarenns

Guten Tag, für die Weiterentwicklung Ihrer bestehenden Marketplace-Plattform mit React, Node/NestJS, MongoDB und REST-APIs bringe ich Senior-Erfahrung in robusten Datenflüssen, Integrationen und automatisierten Tests mit. Zahlungs-, Subscription-, Referral- und Auszahlungslogik würde ich mit besonderem Augenmerk auf Idempotenz, Auditierbarkeit und sichere Zustandsübergänge umsetzen. AWS übernehme ich auf Basis der vorhandenen Umgebung und nach einer kurzen Prüfung des bestehenden Setups; ich verspreche hier keine allgemeine AWS-Expertise jenseits des konkreten Systems. Ich würde mit einer kompakten Code- und Architekturaufnahme starten, anschließend Meilensteine, Annahmen und einen realistischen Festpreis ableiten. Mein Richtwert liegt bei 80 €/h netto. Gern bespreche ich Repository, aktuelle Zahlungsanbieter, AWS-Setup und die Prioritäten der nächsten Phase. Viele Grüße Waldemar Enns