Software Engineer (.NET/React + SDK Architecture)

  • Madison, WI, WI
  • Posted 2 days ago | Updated 8 hours ago

Overview

On Site
Contract - W2

Skills

Software Engineer (.NET/React + SDK Architecture)

Job Details



Location: Hbyrid WFH - Greater Madison Area


Duration: Open; initial 6-12 months with potential extension


Number of positions- 2-3


Equipment -candidates must use their own equipment.


Currently seeking a Software Engineer with strong .NET Core (C#) and React.js development experience, ideally combined with hands-on knowledge of Fiserv SDKs (Architect SDK, FirstAPI). This role will support financial product integrations, focusing on mobile and web SDK implementation, secure API connections, and ACH payment workflows.


Candidates with direct Fiserv SDK experience are highly preferred. However, strong .NET and React engineers who can learn and adapt quickly to the SDK will also be considered.


Key Responsibilities



  • Design, develop, and maintain software using .NET Core (C#) and React.js.

  • Integrate Fiserv Architect SDK for mobile and web applications.

  • Implement server-to-server and client integrations with Fiserv FirstAPI Gateway.

  • Work with RESTful APIs secured via HMAC authentication, OAuth2 session tokens, and payload encryption.

  • Support ACH payment workflows, including enrollment, tokenization, updates, and account closure.

  • Configure and customize SDK-driven UI workflows (multi-step screens, multilingual, error handling).

  • Ensure secure management of API keys, secrets, and tokens, following compliance and security best practices.

  • Collaborate with cross-functional stakeholders (architecture, engineering, product) to align designs with business needs.

  • Troubleshoot and resolve integration issues across SDK, APIs, and backend systems.


Required Qualifications



  • 5+ years of software engineering experience.

  • Strong skills in .NET Core (C#) and React.js development.

  • Familiarity with SDK integration (mobile/web), especially in financial services or payments.

  • Knowledge of API integration patterns (REST, OAuth2, HMAC, encryption).

  • Experience working in enterprise architecture environments with scalability and compliance requirements.

  • Strong analytical, debugging, and problem-solving skills.


Preferred Qualifications



  • Hands-on experience with Fiserv Architect SDK and Fiserv FirstAPI gateway.

  • Understanding of ACH payments, tokenization, and secure data flows.

  • Experience with mobile SDK integration (iOS, Android) in addition to web.

  • Located in Madison, WI (preferred) or MN/IL.



Beacon Hill is an equal opportunity employer and individuals with disabilities and/or protected veterans are encouraged to apply.


California residents: Qualified applications with arrest or conviction records will be considered for employment in accordance with the Los Angeles County Fair Chance Ordinance for Employers and the California Fair Chance Act.


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Completion of this form is voluntary and will not affect your opportunity for employment, or the terms or conditions of your employment. This form will be used for reporting purposes only and will be kept separate from all other records.


Company Profile:

Beacon Hill Technologies, a premier National Information Technology Staffing Group, provides world class technology talent across all industries utilizing a complete suite of staffing services. Beacon Hill Technologies' dedicated team of recruiting and staffing experts consistently delivers quality IT professionals to solve our customers' technical and business needs.

Beacon Hill Technologies covers a broad spectrum of IT positions, including Project Management and Business Analysis, Programming/Development, Database, Infrastructure, Quality Assurance, Production/Support and ERP roles.


Learn more about Beacon Hill and our specialty divisions, Beacon Hill Associates, Beacon Hill Financial, Beacon Hill HR, Beacon Hill Legal, Beacon Hill Life Sciences and Beacon Hill Technologies by visiting .


Benefits Information:


Beacon Hill offers a robust benefit package including, but not limited to, medical, dental, vision, and federal and state leave programs as required by applicable agency regulations to those that meet eligibility. Upon successfully being hired, details will be provided related to our benefit offerings.




We look forward to working with you.

Beacon Hill. Employing the Future

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