Engineering a High-Trust Web3 P2P Payment Engine (NDA)

Written by

CedrTech

Publication date

Dec 7, 2025

Time to read

4 min to read

Digital technology illustration featuring a glowing blue shield and blockchain network nodes. Text reads "Secure P2P Engine Fintech Web3 SaaS" with a lock icon, representing secure payment architecture.

Bridging the Gap Between Traditional Fintech SaaS and Decentralized Settlement

Here is the revised article. I have replaced the specific project name with professional placeholders (e.g., “The Platform,” “NDA Project”) while keeping the technical details sharp and convincing. This approach is very common in high-level IT outsourcing portfolios.


Case Study: Engineering a High-Trust Web3 P2P Payment Engine (NDA)
Bridging the Gap Between Traditional Fintech SaaS and Decentralized Settlement
In the high-stakes world of financial technology, speed usually comes at the cost of security. For this NDA Project, a confidential Fintech client approached CedrTech with a massive challenge: build a “Stripe-like” experience for peer-to-peer (P2P) payments that leverages the immutability of blockchain without sacrificing the speed of modern SaaS.
Our team was tasked with architecting the full lifecycle—from smart contract auditing to frontend integration—creating a platform that processes high-volume transactions with military-grade security.
This case study explores how we delivered a scalable, multi-chain solution that allows enterprises to integrate trustless escrow payments via a simple API.

The Challenge: Trust, Scale, and Compliance

The client required a platform that could serve as the hidden infrastructure layer for marketplaces and financial apps. The critical requirements were:

  • Trustless Architecture: Removing human intermediaries by using automated Smart Contract Escrow.
  • Multi-Chain Agnostic: Seamless operation across both EVM-compatible chains and high-speed networks like Solana.
  • Regulatory Compliance: Integrating rigorous KYC/AML (Know Your Customer) checks into a decentralized flow.
  • Enterprise Scalability: Handling thousands of concurrent event signatures and webhooks without latency.

The Solution: A Hybrid Web3 Architecture

To deliver on these requirements, CedrTech engineered a modular system that combines the speed of centralized caching with the security of decentralized settlement.

1. Smart Contract Escrow & Settlement

We developed a robust set of smart contracts to act as the “trust engine.” Funds are never held by the SaaS platform directly; instead, they are locked in automated escrow contracts that release funds only when specific, cryptographically verifiable conditions are met.

  • Tech: Solidity (EVM), Rust + Anchor (Solana), Hardhat/Foundry.

2. High-Performance Event Indexing

Direct blockchain querying is too slow for consumer-grade applications. We built a custom indexer layer that listens to on-chain events (e.g., PaymentLocked, DisputeRaised) and instantly updates the off-chain PostgreSQL database. This ensures the dashboard shows real-time status updates without waiting for block confirmations.

  • Tech: The Graph, Subsquid, Kafka/RabbitMQ for event streaming.

3. Compliance-First Identity Layer

Security in Fintech is non-negotiable. We integrated top-tier identity verification providers directly into the wallet connection flow, ensuring that every participant is verified against global sanctions lists before a transaction can be initiated.

  • Tech: SumSub, Onfido, Persona integrations.

Tech Stack Deep Dive

Our team selected a technology stack optimized for concurrency, type safety, and institutional-grade security.

Backend Core

  • NestJS (TypeScript): Provides a modular architecture that allows for easy microservices scaling and strict type safety.
  • PostgreSQL & Redis: Used for persistent data storage and high-speed caching of session data.
  • Kafka / RabbitMQ: Handles complex event streaming between the blockchain indexers and the main application.

Smart Contracts & Blockchain

  • Solidity (EVM): For deployment on Ethereum, Polygon, and other EVM chains.
  • Rust + Anchor: Used for high-performance contracts on the Solana network.
  • Hardhat & Foundry: Employed for rigorous testing and development environments.
  • Infrastructure: Alchemy, Infura, QuickNode, and The Graph/Subsquid for reliable node connections and data indexing.

Frontend & User Experience

  • Next.js (React): Ensures superior SEO, fast rendering performance, and a smooth user experience.
  • Tailwind CSS: For rapid, responsive UI development.
  • Web3 Integration: Wagmi, Viem, Web3Modal, and RainbowKit for seamless wallet connections; Solana Wallet Adapter for non-EVM support.

Security & Compliance

  • Identity Verification: Integration with SumSub, Onfido, and Persona for KYC/AML/KYB.
  • Key Management: HSM/KMS key storage to protect asset flows and API keys.
  • Monitoring: Sentry for error tracking, Prometheus for metrics, and OWASP ASVS standards for security auditing.

DevOps & Cloud

  • Containerization: Docker and Kubernetes/ECS for orchestration.
  • Cloud Providers: AWS/GCP for scalable hosting.
  • CI/CD: Automated pipelines ensuring zero-downtime deployments.

Key Features Delivered

Automated Dispute Resolution

By utilizing smart contract logic, the platform reduces operational overhead. If a transaction meets pre-defined cryptographic signatures, funds are released automatically. Disputes are flagged only when on-chain data contradicts off-chain agreements, saving the client massive customer support costs.

“Infrastructure-as-a-Service” API

We built the system to be white-labeled. The client’s partners can plug this P2P engine into their existing apps using our Restful APIs and Webhooks. This turns a complex blockchain process into a few simple API calls for the end-user.

Immutable Audit Trails

Every transaction leaves a footprint. The system automatically generates a unified audit log that combines on-chain transaction hashes with off-chain metadata, providing a clear path for financial audits and reporting.