Senior Fullstack Engineer

About the Company

Overflow is a Series C, growth-stage technology company on a bold mission: to inspire the world to give. We're a vertical fintech and SaaS platform unlocking more ways to give — cash, stock, crypto, and beyond — through a beautifully designed ecosystem built for high-impact churches, nonprofits, and mission-driven institutions.

Responsibilities

• Drive Product-Led Growth by architecting features for self-onboarding, subscription upgrades, and e-commerce checkout flows
• Own complete features from database schema and RESTful API design to polished frontend implementation
• Write clean, well-tested, and maintainable code while contributing to engineering standards
• Partner with Product, Design, and Data to run experiments and A/B tests
• Identify technical debt and contribute to architectural improvements for scalability
• Mentor junior engineers and participate in on-call rotations

Requirements

• 5+ years of fullstack software engineering experience
• Strong proficiency in React, TypeScript, and Node.js
• Deep experience designing scalable RESTful APIs and working with relational databases
• Strong product sense and understanding of product-led growth mechanics
• Demonstrated ability to lead technical initiatives and make architectural decisions

Preferred Qualifications

• Experience integrating with billing and subscription platforms
• Experience in fintech, payments infrastructure, or donation platforms
• Experience at a Series B or growth-stage startup