Senior Mainframe Developer Jobs in Maryland

Senior .NET Developer

Location: Columbia, MD

Job Type: Full-Time

Position Overview

We are seeking a Senior .NET Developer for the design, development, and modernization of enterprise applications and distributed systems. This is a hands-on technical role requiring strong expertise in .NET, AWS, APIs, DevOps, enterprise integrations, and scalable application architecture. The ideal candidate will work closely with architects, clients, and engineering teams to deliver secure, high-quality enterprise solutions in fast-paced environments.

Key Responsibilities

- Perform the design, development, enhancement, and support of enterprise-grade .NET applications
- Collaborate with architects, business analysts, clients, and engineering teams on solution design and implementation
- Perform technical discussions, architecture reviews, and client-facing workshops
- Design and develop scalable, secure, and maintainable applications using modern .NET technologies
- Develop RESTful APIs, backend services, distributed applications, and enterprise integrations
- Build and support batch processing jobs, automation workflows, and backend services
- Provide technical expertise, code reviews, mentoring, and development guidance
- Refactor and optimize applications following enterprise architecture standards and best practices
- Troubleshoot production issues, perform root cause analysis, and support performance tuning activities
- Contribute to CI/CD pipelines, DevOps automation, deployment strategies, and release management
- Work closely with cloud and infrastructure teams within AWS environments
- Support database design, optimization, migration, and integration activities
- Develop technical documentation, architecture artifacts, and operational runbooks
- Participate in Agile/Scrum ceremonies and continuous improvement initiatives

Required Qualifications

- 10–15 years of hands-on experience in enterprise .NET application development
- Proven experience as a Senior Lead Developer
- Strong client-facing communication and stakeholder management skills
- Experience collaborating with enterprise architects and cross-functional teams

Technical Skills

Strong expertise with:
- C#, ASP.NET, ASP.NET Core, .NET-Framework, .NET Core, .NET 6+
- REST APIs, Web-Services, gRPC
- Entity Framework / EF Core
- Angular and/or React
- JavaScript / TypeScript
- LINQ, Windows Services, PowerShell scripting

Strong understanding of:
- Object-Oriented Programming (OOP)
- SOLID principles and design patterns
- Secure coding practices
- Scalable and distributed system architecture

Hands-on experience with:
- Microservices architecture
- API integrations
- Git, Azure DevOps, and CI/CD pipelines
- DevOps automation
- Docker and Kubernetes/container orchestration platforms

Database experience with:
- Microsoft SQL Server and DB2
- Stored procedures, query optimization, and performance tuning
- Data migration and integration

Additional experience with:
- Kafka, RabbitMQ, or similar messaging technologies
- Enterprise production support and troubleshooting
- Agile/Scrum delivery environments

Cloud Experience

Experience with AWS services including EC2, S3, IAM, CloudWatch, cloud deployments, and monitoring.

Preferred Qualifications

- Experience supporting enterprise modernization and digital transformation initiatives
- Experience in regulated environments such as government, healthcare, financial services, or large enterprises
- Exposure to hybrid and multi-cloud environments
- Experience contributing to enterprise architecture and solution planning discussions