Senior Backend .NET Developer / Funding / NYC

About the role

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.

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

Requirements

• 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
• Experience with .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
• Proven ability to improve automated test coverage using unit and integration testing frameworks such as NUnit

Qualifications

• Experience modernizing monolithic applications into microservices architectures
• Familiarity 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

Skills

• Modern .NET development
• Scalable backend systems
• Mentoring through technical leadership

Benefits

The offer includes:

• 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