Staff Software Engineer, Credit Underwriting

Since we opened our doors in 2009, the world of commerce has evolved immensely, and so has Square. After enabling anyone to take payments and never miss a sale, we saw sellers stymied by disparate, outmoded products and tools that wouldn't work together.

So we expanded into software and started building integrated, omnichannel solutions – to help sellers sell online, manage inventory, offer buy now, pay later functionality, book appointments, engage loyal buyers, and hire and pay staff. Across it all, we've embedded financial services tools at the point of sale, so merchants can access a business loan and manage their cash flow in one place. Afterpay furthers our goal to provide omnichannel tools that unlock meaningful value and growth, enabling sellers to capture the next generation shopper, increase order sizes, and compete at a larger scale.

Today, we are a partner to sellers of all sizes – large, enterprise-scale businesses with complex operations, sellers just starting, as well as merchants who began selling with Square and have grown larger over time. As our sellers grow, so do our solutions. There is a massive opportunity in front of us. We're building a significant, meaningful, and lasting business, and we are helping sellers worldwide do the same.

The Role

Square Banking has revolutionized the way businesses and consumers obtain the funding needed to achieve their goals. Unlike traditional business financing products, Square Banking extends offers to pre-qualified sellers with no application process, funds are deposited as soon as the next business day, and repayment happens as a fixed percentage of daily card sales. Since the product launched in 2014, Square Banking has offered billions of dollars in loans to hundreds of thousands of sellers.

As a Staff Software Engineer on the Credit Underwriting Team, you will help grow and expand access to credit for our Square sellers. You will be responsible for designing, building and owning sophisticated underwriting services that leverage data and machine learning technologies to originate and approve a variety of lending products. Our customers are internal teams iterating on existing loan products as well as experimenting with brand new loan structures. Our backend is the powerhouse behind all of loan origination, and our frontend enables product teams to customize, test, and manage the credit policies behind these loans. You will work primarily on our backend systems.

You Will

• Solve ambiguous, high-risk, and cross-team challenges in underwriting systems by working directly in the code and carrying solutions from implementation to resolution across the lending stack


• Guide the long-term technical strategy for underwriting services while contributing hands-on to critical lending platform capabilities


• Partner with engineering, product, risk, and data science teams in shaping and developing novel lending capabilities.


• Raise the technical bar through design reviews and architectural guidance, creating your own designs for underwriting systems and providing feedback on designs across lending teams, setting high standards for reliability, maintainability, and extensibility


• Mentor engineers to grow their technical depth and leadership capabilities, fostering expertise in underwriting domain knowledge and platform development


• Further develop a best-in-class underwriting platform: ensuring robust APIs, clear documentation, and responsive support that enables credit policy teams to move quickly and safely

You Have

• 12+ years of backend engineering experience with proven organizational impact


• Expertise in Go, Ruby, or Kotlin with openness to learn others


• Proven track record of architecting and scaling high-reliability financial systems with high operational excellence, fault tolerance, and data integrity


• Strong mentorship, cross-team collaboration, and technical communication skills, with experience building trust across teams and functions


• Ability to decompose complex, ambiguous problems into maintainable solutions


• (optional) Domain experience in lending, credit underwriting, or consumer credit systems

Technologies We Use and Teach

• AWS


• Go


• Ruby on Rails


• Kafka


• Terraform


• ES6 & TypeScript


• React