Senior Application Developer Jobs in Middleton, WI

It Starts Here:

Santander is a global leader and innovator in the financial services industry and is evolving from a high-impact brand into a technology-driven organization. Our people are at the heart of this journey and together, we are driving a customer-centric transformation that values bold thinking, innovation, and the courage to challenge what's possible. This is more than a strategic shift. It's a chance for driven professionals to grow, learn, and make a real difference.

If you are interested in exploring the possibilities We Want to Talk to You!

The Difference You Make:

The Senior Developer, Application Development serves as a highly experienced, hands-on technical contributor responsible for the development, enhancement, support, and stability of business-critical Fixed Income and Securitized Products applications. This role combines deep technical expertise in Java, C#/.NET, ASP.NET, API development, SQL Server, and enterprise application support with strong business engagement to deliver reliable, scalable, and high-performing solutions.

The Senior Developer plays a key role in the analysis, design, development, troubleshooting, production support, and modernization of applications that support trading, operations, risk, market data, and reporting functions. The role requires a strong understanding of Fixed Income and Securitized Products markets, exceptional analytical skills, and the ability to collaborate effectively with business stakeholders and technology teams to solve complex technical and operational challenges.

• Act as a senior hands-on C#/.NET developer supporting multiple business-critical applications and services.
• Design, develop, enhance, and maintain ASP.NET applications, APIs, backend services, and SQL Server-based solutions.
• Provide advanced expertise in application support, production issue resolution, root cause analysis, and platform stability initiatives.
• Partner with Fixed Income and Securitized Products business users, operations teams, and technology stakeholders to translate business requirements into reliable technical solutions.
• Support and enhance platforms involved in trade processing, positions management, pricing, market data integration, reporting, and regulatory workflows.
• Design and implement scalable, high-performance solutions while ensuring data integrity, operational resiliency, and maintainability.
• Develop and optimize SQL Server database components, including T-SQL, stored procedures, query performance tuning, data analysis, and troubleshooting.
• Lead troubleshooting efforts across application, database, integration, and performance-related issues.
• Contribute to system modernization, technical debt reduction, automation, and continuous improvement initiatives.
• Accurately estimate development effort, identify technical risks, and support project planning and delivery commitments.
• Mentor junior and mid-level developers while promoting engineering best practices, code quality, and knowledge sharing.
• Collaborate closely with architects, product owners, support teams, and business stakeholders to ensure successful delivery and operational excellence.
• Maintain strong focus on data accuracy, controls, performance optimization, and operational efficiency.

What You Bring:
To perform this job successfully, an individual must be able to perform each essential duty satisfactorily. The requirements listed below are representative of the knowledge, skill, and/or ability required. Reasonable accommodation may be made to enable individuals with disabilities to perform the essential functions.

Education:

• Bachelor's Degree: in related field or equivalent demonstrated through a combination of work experience, training, military service, or education - Required

Qualifications:

• 9+ Years Information Technology, Technical Application Development, or similar experience. - Required.
• 7+ years of hands-on experience developing and supporting enterprise applications using C#/.NET technologies with hands-on Java development experience.
• Strong expertise with the following:
  • C#
  • Java
  • .NET Framework / .NET Core
  • ASP.NET MVC and Web Applications
  • RESTful APIs and backend service development
  • Object-oriented design principles and design patterns
• Advanced experience with Microsoft SQL Server, including:
  • T-SQL development
  • Stored procedures
  • Query optimization
  • Database troubleshooting
  • Data analysis and reporting support

Domain Experience:

• Experience supporting Fixed Income and Securitized Products technology platforms.
• Functional understanding of Fixed Income products and structured finance instruments, including:
  • Mortgage-Backed Securities (MBS)
  • Asset-Backed Securities (ABS)
  • Commercial Mortgage-Backed Securities (CMBS)
  • Collateralized Mortgage Obligations (CMO)
  • Agency and Non-Agency Securities
  • Pass-Through Securities and Structured Products.
  • Trade lifecycle management
  • Fixed Income trading workflows
  • Securitized Products trading and operational workflows
  • Pricing and valuation concepts
  • Positions and inventory management
  • Market data integration and consumption
  • Reporting and regulatory processes
  • Cashflow generation and payment structures
  • Pool and loan-level characteristics
  • Principal and interest distributions
  • Repayment, amortization, and factor-based securities concepts
  • Trade settlement and lifecycle events
• Demonstrated ability to collaborate with traders, sales, operations teams, business analysts, and product owners to understand business requirements, analyze issues, and deliver effective technology solutions.
• Functional understanding of how MBS, ABS, CMBS, and related securitized instruments are originated, traded, priced, settled, serviced, and reported across front-office, middle-office, and operational workflows.

Certifications:

• No Certifications listed for this job.

It Would Be Nice For You To Have:

• Established work history or equivalent demonstrated through a combination of work experience, training, military service, or education.
• Prior experience supporting Capital Markets, Fixed Income, or Securitized Products trading businesses within an Investment Banking environment.
• Experience supporting front-office and middle-office trading platforms.
• Familiarity with Bloomberg, market data feeds, security master platforms, and trade processing ecosystems.

Work Authorization & Sponsorship:
Applicants must be legally authorized to work in the United States on a full-time basis without requiring employer sponsorship to commence employment.

What Else You Need To Know:

The base pay range for this position is posted below and represents the annualized salary range. For hourly positions (non-exempt), the annual range is based on a 40-hour work week. The exact compensation may vary based on skills, experience, training, licensure and certifications and location.

Base Pay Range:

Minimum:

We Value Your Impact:

Your contribution matters and it's recognized. You can expect a fair and competitive rewards package that reflects the impact you create and the value you deliver. We know rewards go beyond numbers. Offering more than just a paycheck our benefits are designed to support you, your family and your well-being, now and into the future. Santander Benefits - 2026 Santander OnGoing/NH eGuide (foleon.com)

Risk Culture:

We embrace a strong risk culture and all of our professionals at all levels are expected to take a proactive and responsible approach toward risk management.

EEO Statement:

At Santander, we value and respect differences in our workforce. We actively encourage everyone to apply. Santander is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, genetics, disability, age, veteran status or any other characteristic protected by law.
Working Conditions:

Frequent minimal physical effort such as sitting, standingand walking is required for this role. Depending on location, occasional moving and lifting light equipment and/or furniture may be required.

Employer Rights:

This job description does not list all of the job duties of the job. You may be asked by your supervisors or managers to perform other duties. You may be evaluated in part based upon your performance of the tasks listed in this job description. The employer has the right to revise this job description at any time. This job description is not a contract for employment and either you or the employer may terminate your employment at any time for any reason.

What To Do Next:

If this sounds like a role you are interested in, then please apply.

We are committed to providing an inclusive and accessible application process for all candidates. If you require any assistance or accommodation due to a disability or any other reason, please contact us at TAOps@santander.us to discuss your needs.