.NET Developer

Eliassen Group; Madison (WI); Remote; USD 90,000 - 103,000; Part time

Job summary

Eliassen Group is seeking experienced .NET developers to support a large-scale modernization initiative. Focus areas include backend services, REST APIs, and integrations that replace legacy mainframe functionality with modern .NET-based services and APIs.

The role emphasizes designing scalable, enterprise-grade solutions, working with event-driven architectures, and collaborating with multiple teams to modernize critical applications.

Qualifications

• Proven experience with .NET/C# backend development.
• Experience building REST APIs and backend services.
• Strong understanding of enterprise application development.
• Experience integrating multiple applications or systems.
• Proven ability to translate legacy functionality into modern services.
• Mid-to-senior level development experience.
• Experience with Kafka, event-driven architectures, or related technologies is a plus.
• Interest in AI/LLM is a plus.

Responsibilities

• Design and develop backend services and REST APIs using modern .NET.
• Build replacement services as part of a legacy mainframe modernization effort.
• Review existing mainframe code to understand business logic for new solutions.
• Develop event-driven services, consumers, and publishers.
• Build and support integrations with enterprise and third-party applications.
• Contribute to finance-related services, APIs, payroll workflows, and data integrations.
• Work within shared enterprise repositories and established development standards.
• Collaborate with engineering teams on modernization of critical enterprise applications.

Skills

.NET/C# development

REST APIs

Enterprise app development

System integrations

Production-grade applications

Legacy modernization

Event-driven architecture

AI/LLM interest

Tools

Kafka

Apicurio

Salesforce

Concur

OneStream

Job description

.NET Developer

Anywhere

Type: Contract-to-Hire

Category: Development

Industry: Manufacturing

Workplace Type: Remote

Standard Hours: Open

Reference ID: JN -102026-109023

Date Posted: 10/11/2026

Shortcut: http://careers.eliassen.com/ZIYhXc

Description

Remote

• Candidates must be located in these states: Arizona, Connecticut, Massachusetts, Missouri, New Jersey, New York, Florida, Vermont, Virginia, Texas and Wisconsin

Our client seeks experienced .NET Developers to support a large-scale modernization initiative replacing legacy mainframe applications with modern .NET-based services and APIs. You will focus on backend development, enterprise integrations, and event-driven applications. You will build scalable services that integrate with internal and third-party systems and collaborate with engineering teams to modernize critical enterprise applications.

This is a contract to hire opportunity. Applicants must be willing and able to work on a w2 basis and convert to FTE following contract duration. For our w2 consultants, we offer a great benefits package that includes Medical, Dental, and Vision benefits, 401k with company matching, and life insurance.

Rate: $65.00 to $75.00/hr. w2

JN -102026-109023

Responsibilities

• Design and develop backend services and REST APIs using modern .NET.
• Build replacement services as part of a legacy mainframe modernization effort.
• Review existing mainframe code to understand business logic and use it as reference when developing new solutions.
• Develop event-driven services, consumers, and publishers.
• Build and support integrations with enterprise and third-party applications.
• Contribute to finance-related services, APIs, payroll workflows, and data integrations.
• Work within shared enterprise repositories and established development standards.
• Collaborate with engineering teams on the modernization of critical enterprise applications.

Experience Requirements

• Strong hands-on experience with .NET/C# development.
• Experience developing REST APIs and backend services.
• Strong understanding of enterprise application development.
• Experience working with integrations between multiple applications or systems.
• Experience developing and supporting production‑grade applications.
• Ability to understand existing application logic and translate legacy functionality into modern services.
• Mid-level to senior development experience.
• Preferred: Kafka, event‑driven architecture, event sourcing, messaging architectures, event consumers and publishers, consumer‑driven services, third‑party integrations, finance or payroll‑related applications, integrations with platforms such as Salesforce, Concur, or OneStream, legacy or mainframe modernization initiatives, Apicurio. Interest in AI/LLM is a plus.

Recruitment Transparency Notice

Eliassen Group values transparency in our recruitment practices. Please be advised that Eliassen Group utilizes artificial intelligence (AI) tools as part of its initial application screening and hiring process. You may receive email and SMS notifications from the Eliassen Virtual Recruiting Team ([e-mail], 781-808-2924) inviting you to complete a brief voice screening as part of your application process. These tools assist our hiring teams in different ways, including but not limited to, assistance in reviewing application materials to help identify candidates whose qualifications most closely match the requirements of the position. All AI‑assisted evaluations and responses are reviewed by human recruiters before any hiring decisions are made. The use of AI in our process is intended to support fairness, efficiency, and consistency, and Eliassen Group takes measures to prevent bias or discrimination in connection with its hiring practices. By proceeding, you acknowledge, agree, and consent to Eliassen Group’s use of these tools, including AI tools, as part of the application and hiring process.

Skills, experience, and other compensable factors will be considered when determining pay rate. The pay range provided in this posting reflects a W2 hourly rate; other employment options may be available that may result in pay outside of the provided range.

W2 employees of Eliassen Group who are regularly scheduled to work 30 or more hours per week are eligible for the following benefits: medical (choice of 3 plans), dental, vision, pre‑tax accounts, other voluntary benefits including life and disability insurance, 401(k) with match, and sick time if required by law in the worked‑in state/locality.

If anyone reaches out to you about an open position connected with Eliassen Group, please ensure that you are working directly with us by confirming the following:

When you work with Eliassen Group, all email communication will come from an Eliassen.com address, never Gmail, Yahoo, etc.

Eliassen Group will never ask you for personal information (home address, bank account, or check routing number) until you have worked with someone clearly associated with Eliassen Group.

If you have any indication of fraudulent activity, please contact [e-mail].

About Eliassen Group

Eliassen Group is a strategic consulting firm that helps organizations reach further and achieve more through our technology, business advisory, and life sciences solutions. For nearly 40 years, we have combined exceptional people, deep domain expertise, and intelligent capabilities to expand our clients’ capacity and accelerate meaningful outcomes. We are driven by a purpose to positively impact the lives of our employees, clients, consultants, and the communities we serve.

Eliassen is committed to building a diverse and inclusive team from a variety of backgrounds, perspectives, and skills. We are an Equal Opportunity and affirmative action Employer and all employment decisions are based on merit, performance, and business needs. Eliassen does not discriminate on the basis of race, color, gender identity or expression, sexual preference or orientation, sex (including pregnancy, childbirth, and related medical conditions), marital status, creed, religion, physical or mental disability, genetic information, military or veteran status, age, ancestry, national origin, citizenship status, prohibited criminal record inquiries of applicants and employees, or any other category protected by federal, state, or local laws.

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