Full-Stack, Backend Leaning, SWE

Affiniti; New York (NY); Hybrid; USD 150,000 - 240,000; Full time

Benefits offered by this job

Relocation assistance

Free meals in NYC

Tech setup provided

Health, dental, and vision insurance

Job summary

Affiniti is building the financial operating system for small businesses across America, with the frontend as the bridge. We’re hiring engineers in NYC in-office hybrid with relocation support.

You will own the backend architecture, APIs, data models, and the reliability foundations that scale our product. You’ll also collaborate across product and design to turn ambiguous needs into clean, maintainable systems, sometimes touching frontend as needed.

Qualifications

• 2+ years of production engineering experience in an early-stage startup or similar environment.
• Strong expertise in TypeScript and Node.js, with opinions on API design and data modeling.
• Demonstrated ability to own features from idea to production with focus on reliability and performance.

Responsibilities

• Own the backend architecture behind our product: APIs, data models, and core logic to scale and stay reliable.
• Drop into frontend flow when needed: build React components and trace issues from browser to database.
• Build systems for complex financial products with data-rich integrations and robust error handling.
• Focus on data integrity, API latency, failure modes, and performance edge cases.
• Collaborate with product and design to translate user needs into solid technical solutions.
• Advocate for users in technical decisions, turning ambiguous needs into clean implementations.

Skills

TypeScript

Node.js

API design

Data modeling

Backend architecture

System reliability

End-to-end ownership

Product instincts

AI tools

High velocity delivery

Tools

Claude Code

Codex

Job description

About This Role

There is an enormous gap between the technology built in Silicon Valley and what the average small business owner in America can actually get their hands on. The pharmacist in rural Louisiana. The auto dealer in the Midwest. The vet clinic owner who has done their books the same way for twenty years. They run the businesses that hold American communities together, and the software serving them has never reflected how much they matter.

Affiniti is closing that gap. We're building the financial operating system for small businesses across America, and the frontend is the bridge. Every dashboard you ship, every interaction you refine, every millisecond you shave off a load time is technology finally reaching the people who needed it most and never got it.

If you want to write code that matters beyond the product itself, this is that opportunity.

About Affiniti, and who we look for:

LOCATION

NYC (in office), VAN or TO (hybrid)

EXPERIENCE

We are hiring for multiple engineers with 2+ YOE. There is no upper limit.

TOTAL COMPENSATION

$150K to $240K + Equity (Location and experience adjusted)

• Reimbursed Relocation
• Free Lunch and Dinner (In NYC)
• Paid Technology Equipment Set Up
• Health, Dental, and Vision Insurance Fully Covered

Tech Stack

TypeScript, Node.js, and React

Key Responsibilities

• Own the backend architecture behind our product. APIs, data models, business logic, and the foundational decisions that determine how the product scales, performs, and stays reliable.
• Drop into the full stack when it counts. Build frontend flows, wire up React components, and trace a bug from the browser to the database without waiting on anyone.
• Build the systems that power complex financial products. The kind of backend where messy financial data, integrations, and business logic become simple, reliable experiences for customers.
• Obsess over the details that separate software that works from software customers can trust: data integrity, API latency, failure modes, query performance, and the edge cases most engineers skip.
• Partner closely with product and design to push past the requirements. Challenge assumptions, propose better solutions, and make sure what we build solves the actual customer problem - not just the technical specification.
• Turn ambiguous user needs into clean, maintainable implementations. And advocate for the user in every technical decision.

What You'll Bring

• 2+ years of production engineering experience. Early-stage startup experience strongly preferred.
• Deep fluency in TypeScript and Node.js, with real opinions about API design, data modeling, backend architecture, and system reliability.
• End-to-end ownership and strong product instincts. You can take a feature from idea to shipped without a frontend engineer holding your hand, and you care as much about the customer experience as the systems underneath it.
• You know how to build with AI, not just use it. Tools like Claude Code, Codex, and other coding agents are a core part of your engineering workflow, and you know how to use them to dramatically increase your speed and output without outsourcing technical judgment.
• A track record building complex, data-rich products backed by systems operating under real reliability and performance constraints.
• Speed without the debt. You move fast without leaving behind the kind of backend mess that makes a codebase painful six months later.
• High ownership. You take problems as your own and see them through - the mark of the people who thrive here.

Equal Opportunity Employment

Affiniti is an equal opportunity employer. We are committed to building a diverse and inclusive workplace and consider all qualified applicants for employment without regard to race, color, religion, sex, pregnancy, national origin, age, disability, genetic information, veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by applicable federal, state, or local law.

Affiniti provides reasonable accommodations to qualified individuals with disabilities and applicants with disabilities throughout the recruiting process, consistent with applicable law.