Programmable Escrow & Fraud-Resilient Marketplace Payments
A programmable Solana escrow and event-driven fraud-risk architecture for marketplace settlement and post-return payment release.
Overview & Research Motivation
Built a marketplace payment architecture designed to reduce refund and settlement fraud by combining programmable on-chain escrow with event-driven risk scoring and settlement workflows.
The Core Systems Problem
- Marketplace settlement must balance timely seller payment with the risk of refund abuse, return fraud, and premature release of funds after a return event.
- Risk signals and transaction events need to move through a reliable workflow before programmable escrow releases or retains settlement funds.
My Specific Technical Contributions
- Built a Solana escrow protocol in Rust and Anchor using PDA-controlled vaults and programmable settlement logic to automate post-return fund release and reduce refund and settlement fraud.
- Engineered an AWS event-driven backend using EventBridge, Lambda, Step Functions, and DynamoDB.
- Integrated Amazon Fraud Detector for transaction risk scoring.
System Architecture & Verification Pipeline
Escrow Architecture
Solana programs written with Rust and Anchor use Program Derived Address-controlled vaults and programmable settlement rules to hold and release marketplace payments.
Fraud-Risk Pipeline
Transaction and return events are evaluated through Amazon Fraud Detector before the settlement workflow reaches a release decision.
Event-Driven Backend
AWS EventBridge routes events into Lambda functions and Step Functions workflows, with DynamoDB retaining the state needed for settlement processing.
Settlement Workflow
Risk-scoring outputs and post-return events inform programmable keep-or-release transitions for funds held in escrow.
Evaluation & Benchmark Results
Technical Stack & Tools
Known Limitations
- The prototype was developed for HackOn with Amazon, Season 5 and was not presented as a production deployment.
- Risk-scoring quality depends on representative transaction and return-event data.
What I Would Test Next
- Evaluate settlement behavior under a wider range of marketplace return and dispute scenarios.
- Test failure recovery and idempotency across the event-driven settlement workflow.
Connected Systems & Inquiries
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