Lead .Net Full Stack Developer

eSolutionsFirst, LLC; McLean (VA); On-site; USD 140,000 - 190,000; Full time

Job summary

eSolutionsFirst, LLC seeks a senior software engineer to lead full-stack development in a fast-paced environment. You will design and implement scalable web applications using C#/.NET, React, TypeScript, and Next.js 15 App Router, with emphasis on REST APIs and real-time communication.

Experience integrating with ERP systems (Dynamics NAV/ Business Central) and applying secure, observable architectures is essential. Familiarity with AI-assisted tooling and API-first development is highly valued.

Qualifications

• 7+ years of software development experience.
• Strong coding experience in C#/.Net, Unit testing, REST API design.
• Strong React / TypeScript / Next.js 15 App Router, RTK Query, Tailwind CSS, component library patterns.
• Experience integrating with ERP systems (Microsoft Dynamics NAV / Business Central strongly preferred).
• Proven experience designing real-time systems (SignalR, WebSockets, or equivalent).
• OpenAPI/Swagger specification authoring and API contract-first development.

Responsibilities

• Track record delivering complex, multi-module web applications end-to-end.
• Experience with message-driven integration patterns (Azure Service Bus, event-driven architecture, dead-letter handling).
• Security-conscious mindset: OWASP Top 10 familiarity, managed identity patterns, Azure Key Vault.
• Observability and monitoring: Application Insights instrumentation, custom metrics, alerting design.

Skills

C# / .NET

Unit testing

REST API design

React

TypeScript

Next.js 15 App Router

RTK Query

Tailwind CSS

Component library patterns

OpenAPI/Swagger

API contract-first development

SignalR / WebSockets

Azure Service Bus / event-driven

OWASP Top 10 / security

Azure Key Vault

Application Insights / observability

Tools

Claude Code

GitHub Copilot

Job description

Job Summary

7+ years of software development experience.

• Strong coding experience in any of these languages (C# and .Net), Unit testing, REST API design
• Strong React / TypeScript / Next.js 15 App Router, RTK Query, Tailwind CSS, component library patterns
• Experience integrating with ERP systems (Microsoft Dynamics NAV / Business Central strongly preferred)
• Proven experience designing real-time systems (SignalR, WebSockets, or equivalent)
• OpenAPI/Swagger specification authoring and API contract-first development

AI & Tooling

• Hands-on experience with Claude Code, GitHub Copilot, or equivalent AI coding assistants in production development workflows
• Demonstrated ability to prompt LLMs effectively using structured specifications and to critically evaluate generated output
• Familiarity with AI-assisted test generation and automated code review tooling

Architecture & Process

• Track record delivering complex, multi-module web applications end-to-end
• Experience with message-driven integration patterns (Azure Service Bus, event-driven architecture, dead-letter handling)
• Security-conscious mindset: OWASP Top 10 familiarity, managed identity patterns, Azure Key Vault
• Observability and monitoring: Application Insights instrumentation, custom metrics, alerting design