Senior Full Stack Engineer

The 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 serves 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 detect interchange downgrades and enrich transaction metadata automatically.
• 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

• 8+ years of professional engineering experience with a strong Node.js and React background.
• 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.
• At least Intermediate English proficiency.