Senior Full-Stack Engineer

Our client is a payment cost optimization platform that automatically monitors every transaction for interchange and data quality issues — and fixes them in real time. This legal tech company serving 50,000+ lawyers. The client brings enterprise-grade payment intelligence to every business.

You will be an engineer on a small, high-ownership team, working directly with the Founder & Product Owner to build and scale the core platform. You'll design and implement features across the full stack, from data ingestion pipelines to the user-facing interface.

Key Responsibilities

• Build and maintain asynchronous data processing pipelines for payment transaction data
• Integrate with payment processors such as Stripe, Worldpay, and others via API and SFTP file exchange
• Ingest, parse, and extract structured data from Visa and Mastercard PDF rule publications using AI-assisted analysis
• Use extracted card network data to automatically detect interchange downgrades and enrich transaction metadata
• Optimize interchange rates by improving the quality of outbound transaction data sent to processors
• Develop robust, scalable React front-end features for the client’s dashboard and customer-facing tools
• Deploy and operate services on AWS using ECS and Docker in a cloud-native architecture
• Collaborate with PO as a hands-on co-builder — you will own large parts of the codebase

Required Qualifications

• Collaborate with PO as a hands-on co-builder — you will own large parts of the codebase
• Demonstrated experience building payment or financial integrations (Stripe, Worldpay, or similar)
• Comfortable working with asynchronous transaction flows and event-driven architectures
• Experience with SFTP-based data ingestion and file processing at scale
• Strong AWS experience (Lambda, ECS, containerized workloads or similar)
• Excited about applying AI/ML techniques to document parsing and data quality problems
• Self-directed and communicative — you thrive in small, focused teams with high ownership
• Fluent in English (written and spoken) for collaboration with a US-based product owner