Back End Developer

TypeScript Backend Software Engineer - Startup – New York Visa sponsorship not available, US Citizens only. Please do not apply if you are seeking sponsorship Several Backend Software Engineers are required by AI startup who automates the mortgage process, aiming to modernize an outdated industry. Customers include banks, lenders, and brokers, focusing on improving APIs for integration. The company is for a mid-career to senior backend engineer with experience building systems in complex, regulated domains like fintech. You should be comfortable translating intricate business logic into highly reliable, precise code and have a track record of working closely with non-technical subject matter experts. Bonus points if you have experience with AI/ML tooling, DSLs, or workflow orchestration. Requirements Computer Science degree from top-30 program. 3+ years of experience as a software engineer in TypeScript, NestJS, GraphQL, SQL (PostgreSQL), Temporal.io Experience working at a VC- backed company or as founding engineer or at a reputable company still growing fast (e. g. , FAANG), or in FinTech (e. g. , Stripe, CreditKarma), PropTech, or mortgage. Experience gathering requirements from customers or SMEs and translating into products/features for non- technical users (e. g. , fintech, insurance, logistics). Experience designing DSLs for rule encoding is highly preferred. Experience building AI or agentic tooling for non-technical users (e.g., Harvey, Abridge). Experience working on core systems in a regulated space (e.g., Treasury, Insurance). What you'll do: Encode dense, natural language mortgage guidelines into executable logic using TypeScript, custom DSLs, and AI. Take ownership of critical underwriting systems where correctness and precision are paramount. Work side-by-side with mortgage experts to understand nuance, exceptions, and translate their domain knowledge into robust software. Build and maintain internal tooling that empowers underwriters to configure and guide automated decision-making agents. Design for precision, build robust test coverage, and think deeply about failure modes in a high-stakes financial environment. Push into uncharted territory, applying AI in ways the mortgage industry hasn't seen to make lending faster, cheaper, and more accessible. Tech stack TypeScript, NestJS, GraphQL, SQL (PostgreSQL), Temporal.io Show more Show less