Senior Full Stack Engineer

DeWinter Group; New York (NY); Hybrid; USD 160,000 - 200,000; Full time

Job summary

DeWinter Group is seeking a Senior Full-Stack Software Engineer for a hybrid role in New York City. The position focuses primarily on front-end development using React, with back-end services in Java. You will work on a transformative data platform in FinTech, requiring 5+ years of full-stack development experience.

This is a high-impact role, where you'll own full-stack applications, build test automation, and mentor team members. A competitive salary and opportunity for a conversion to full-time employment awaits.

Qualifications

• 5+ years of full-stack development experience.
• Deep expertise in front-end technologies like React/Angular.
• Experience with REST APIs and GraphQL.
• Experience working with Databases (SQL and NoSQL).
• Demonstrated ability to work autonomously.

Responsibilities

• Develop and own full-stack applications with a focus on the front-end.
• Build test automation across the full stack.
• Work closely with Product and UX teams.
• Develop and maintain the application design system.
• Help onboard and mentor new team members.

Skills

React

Java

Spring Boot

TypeScript

JavaScript

REST APIs

GraphQL

SQL

NoSQL

Job description

Title: Senior Full-Stack Software Engineer

Job Type: Contract to Hire (CTH)

Contract Length: End of Year (EOY) conversion to FTE with a base salary range of $160k–200k plus bonus.

Pay Range: $60 - 80/hour

Start Date: 6/15/26

Location: Hybrid—3 days a week in the NYC office, conveniently located next to MSG and Penn Station.

About the Opportunity

Our client, a leader in FinTech, is looking for a skilled Senior Full-Stack Software Engineer to join their team for an End of Year engagement. This project involves creating, enhancing, and maintaining a centralized, real-time syndicated loan data platform. The application is transforming the syndicated loan market by providing unprecedented transparency into loan level details and portfolio positions. The team is rapidly expanding after recently raising $40M. This is a high-impact role that is heavily front-end focused (80%) and requires a self‑motivated professional who can hit the ground running and deliver results quickly.

Key Responsibilities & Deliverables

• Developing and owning full‑stack applications, with a primary focus (80%) on the front‑end using React and back‑end services in Java.
• Building test automation across the full stack, as the team does not have a separate testing team.
• Working closely with Product and UX teams to address client needs with high‑impact and high‑visibility solutions.
• Developing and maintaining the application design system.
• Helping to onboard and mentor new team members, contributing to the technical foundation and culture of the Application Development squad.

Required Skills & Experience

• 5+ years of full-stack development experience.
• Deep expertise in front-end technologies like React/Angular (TypeScript/JavaScript) and back-end development with Java/Spring Boot.
• Experience with REST APIs and GraphQL, along with a good understanding of application architecture and performance optimization.
• Experience working with Databases (SQL and NoSQL).
• Demonstrated ability to work autonomously and manage your own time effectively to meet project goals.
• Strong communication, analytical, and problem‑solving skills to provide clear and concise status updates to the project team.

• W2 only (No C2C or 1099 contractors)