Senior Backend .NET Developer / Funding / NYC

Job Description

A growing fintech company is looking for a Senior Backend Developer to help modernize and scale the core platform that powers its business. Built on ASP.NET 8 and MySQL, the company's flagship platform is undergoing a significant architectural transformation as they migrate from a monolithic application to modern, independently deployable microservices. This role offers the opportunity to work on highly scalable backend systems while helping define the future technical direction of the platform.

In this role, you will work closely with Product Managers, Engineers, and business stakeholders to architect, develop, and deliver new features while improving the reliability, scalability, and maintainability of the existing platform. You'll play a key role in decomposing legacy applications into modern ASP.NET Core services, improving automated test coverage, optimizing database performance, and designing service communication patterns that support long-term growth. This position is ideal for a senior engineer who enjoys solving complex backend challenges while balancing technical excellence with business priorities.

This is an excellent opportunity to join a collaborative engineering team where you'll have a direct impact on architecture, engineering best practices, and the overall evolution of a mission-critical fintech platform. If you're passionate about modern .NET development, scalable backend systems, and mentoring through technical leadership, this role offers significant ownership and the opportunity to shape the future of the company's technology stack.

Required Skills & Experience

• 6+ years of experience developing applications with C# and ASP.NET Core
• 5+ years of experience working with SQL databases such as MySQL or Microsoft SQL Server
• Strong experience designing and building large-scale, high-performance backend systems
• Experience developing RESTful APIs using ASP.NET Core Web API
• Strong knowledge of .NET Core 7+ including Dependency Injection, Configuration, and Logging
• Experience working with Dapper, Json.NET, and data access best practices
• Strong understanding of HTTP, REST APIs, and JSON-based integrations
• Experience defining service contracts, API boundaries, and communication patterns between distributed services
• Proven ability to improve automated test coverage using unit and integration testing frameworks such as NUnit

Desired Skills & Experience

• Experience modernizing monolithic applications into microservices architectures
• Experience with React, Bootstrap, Tailwind CSS, or other modern frontend frameworks
• Familiarity with Redis, RabbitMQ, and event-driven architectures
• Experience working with Nginx and application hosting environments
• Experience using Git within collaborative development teams
• Experience deploying applications to AWS, Azure, or Google Cloud Platform
• Strong troubleshooting, performance tuning, and SQL query optimization skills
• Excellent communication skills with the ability to collaborate directly with business stakeholders and cross-functional teams

What You Will Be Doing Daily Responsibilities

• Design, develop, and deploy new backend features for the company's core fintech platform
• Collaborate with Product Managers, Engineers, and business stakeholders to define technical solutions and deliver business requirements
• Develop and maintain high-performance data access layers using Dapper and MySQL while optimizing query performance and maintaining application SLAs
• Introduce and expand automated unit and integration test coverage using NUnit and modern testing practices
• Analyze, refactor, and migrate legacy monolithic components into independently deployable ASP.NET Core services
• Define service contracts, APIs, and communication patterns between newly extracted microservices and the existing platform
• Troubleshoot production issues and continuously improve application performance, reliability, and scalability
• Participate in architecture discussions and contribute to long-term platform modernization initiatives
• Perform code reviews and promote engineering best practices across the development team
• Help drive technical innovation while maintaining a stable, scalable production environment

The Offer

You Will Receive The Following Benefits

• Competitive Base Salary
• Medical Insurance
• Dental Benefits
• Vision Benefits
• 401(k) Plan
• Paid Time Off
• Professional Development Opportunities
• Modern Technology Stack (.NET 8, ASP.NET Core, MySQL, Microservices)
• Collaborative Engineering Culture with High Technical Ownership
• Opportunity to Help Modernize a Mission-Critical Fintech Platform

Applicants must be authorized to work in the US on a full-time basis now and in the future.

Posted By: James Carmichael