Senior Dotnet Developer

System Soft Technologies; Lansing (MI); Hybrid; USD 83,000 - 124,000; Full time

Job summary

System Soft Technologies is seeking a Senior .NET Application Developer to design, develop, and maintain enterprise applications in a hybrid Lansing environment. Responsibilities include updating ASP.NET MVC 5, Web Forms, and REST/SOAP APIs, plus database work with Oracle 19c and PL/SQL.

Candidate should have 8+ years of .NET experience, strong backend and integration skills, and the ability to collaborate with business stakeholders while ensuring secure, scalable solutions.

Qualifications

• 8+ years of .NET development experience in enterprise settings.
• Strong C#, ASP.NET Web Forms/MVC (4.8) and MVC5 experience.
• Experience with REST and SOAP APIs.
• Database design with Oracle 19c and PL/SQL.
• OAuth2/OIDC authentication and secure API integration.
• Troubleshooting and strong problem-solving skills.
• Excellent written and verbal communication with stakeholders.
• Ability to support multiple legacy applications.

Responsibilities

• Design, develop, and maintain enterprise apps using .NET tech.
• Maintain older Web Forms apps and reporting components.
• Collaborate with stakeholders to gather requirements.
• Ensure security, performance, and coding standards.
• Participate in full software lifecycle from design to deployment.
• Provide ongoing support and resolve production issues.

Skills

C#

ASP.NET MVC

Web Forms

REST APIs

SOAP

Tools

Oracle 19c

Toad/OSD

OAuth2/OIDC

Git

Job description

Job Title: Senior .NET Application Developer

Location: Lansing, MI, 48909 (Hybrid)

Duration: 6+ months contract

Job Responsibilities:

Application and Solution Development: Design, develop, and maintain complex enterprise applications using ASP.NET MVC 5 (Windows), C#, .NET Framework 4.8, SOAP

and REST APIs, and modern web technologies. Maintain older ASP.NET (Web Forms) applications, Microsoft RDLC and Crystal Reports.

WCAG 2.1 and modern web development standards.

Database Development and Modeling: Create and maintain database schemas, stored procedures, and data access layers. Implement business rules, validation, and data integrity controls across Oracle 19c or similar relational systems.

Solution Lifecycle Management: Participate in all phases of the application lifecycle, from requirements gathering and design to development, testing, deployment, and maintenance.

Utilize source control and follow best practices for deploying solutions across development, testing, and production environments.

Support and Troubleshooting: Providing technical support to users (both business and technical), troubleshooting with apps, databases, resolve performance problems, and address security concerns.

Collaboration and Communication: Work directly with business stakeholders, communicate effectively with technical teams, and assist end-users. Demonstrates strong

customer service awareness and orientation.

Ongoing Support: Provide ongoing support for client users by maintaining and enhancing existing .NET applications. Demonstrate flexibility to support multiple legacy

applications and shift between systems as project needs evolve

Required Qualifications:

8+ years of extensive .NET Development experience: Proven experience designing and building complex applications using C#, ASP.NET Web Forms/MVC (Framework 4.8) and

ASP.NET MVC 5 (Windows) ASP.NET (Web Forms, common architectural patterns, and API design.

6+ years of Database Engineering Expertise experience: Experience modeling relational databases, creating schemas, and optimizing queries. Able to manage roles, security, and data quality in an enterprise Oracle 19c environment. Strong Oracle SQL and PL/SQL using Toad/OSD

WCAG 2.1 and modern web development standards.

4+ years of Backend Services and Integrations experience: Strong understanding of web service design, authentication and authorization mechanisms including authentication flows (OAuth2/OIDC), secure API integration, and robust error handling patterns.

Troubleshooting and problem-solving; including the ability to diagnose and resolve complex technical issues utilizing strong analytical and problem-solving skills.

Strong written and verbal communication; discussing application errors with users and other technical staff, describing technology to diverse user groups, preparing

documentation.

Preferred Qualifications

Experience creating custom .NET libraries, reusable components, integration connectors, or using PowerShell for automation tasks.

Experience with ASP.NET Core, understanding of reusable components, dependency injection, and modern frontend technologies like Blazor.

Top Skills & Years of Experience:

8+ years of extensive .NET Development experience: Proven experience designing and building complex applications using C#, ASP.NET Web Forms/MVC (Framework 4.8) and ASP.NET MVC 5 (Windows) ASP.NET (Web Forms, common architectural patterns, and API design.

6+ years of Database Engineering Expertise experience: Experience modeling relational databases, creating schemas, and optimizing queries. Able to manage roles, security, and data quality in an enterprise Oracle 19c environment. Strong Oracle SQL and PL/SQL using Toad/OSD

4+ years of Backend Services and Integrations experience: Strong understanding of web service design, authentication and authorization mechanisms including authentication flows (OAuth2/OIDC), secure API integration, and robust error handling patterns.