Senior .Net Software Engineer

Vaco is partnering with a national wealth management technology organization to hire a Senior Software Engineer focused on backend .NET development, API design, and modernization of core platform applications. This role will be part of a new Tempe-based engineering team and will serve as one of the most senior individual contributors locally. The immediate focus is modernizing legacy applications, including rewriting older systems into modern .NET. This is a backend-heavy role centered on C#, .NET, SQL databases, API design, and integrations across multiple data sources and third-party systems. There may be some front-end exposure, but dedicated front-end developers handle most React work, so the strongest fit will be someone who is much deeper in backend engineering than UI development. This role is based in Tempe and requires onsite presence four days per week. What You'll Be Doing Design, build, test, and deploy backend services and APIs using C#, .NET, and modern engineering practices Support modernization efforts by helping rewrite legacy systems into modern .NET architecture Develop scalable API and integration patterns for data ingestion across multiple internal and third-party sources Work with SQL Server and related database technologies to build reliable, data-centric applications Translate product requirements and architecture guidance into maintainable, production-ready software Author technical design documentation and participate in design reviews for significant changes Build resilient integrations with clear contracts, versioning strategies, error handling, logging, and observability Write clean, testable code and contribute to unit, integration, and end-to-end testing practices Participate in code reviews focused on performance, maintainability, resiliency, and secure coding Troubleshoot production issues, support root-cause analysis, and improve application reliability Partner with product, architecture, QA, DevOps, and engineering peers in Agile delivery cycles Mentor junior and mid-level engineers while helping raise engineering standards across the team Required Experience 7 or more years of professional software engineering experience delivering production systems Strong backend development experience with C#, .NET, and modern .NET frameworks Experience modernizing legacy applications or incrementally improving older systems Strong SQL database experience, including SQL Server or comparable relational databases Experience designing and building RESTful APIs and integration layers Experience with third-party API integrations and data ingestion from multiple sources Experience writing unit and integration tests and working within CI/CD delivery practices Experience working in Agile or Scrum environments with cross-functional teams Strong communication skills with the ability to explain technical decisions clearly Ability to operate as a senior individual contributor and mentor other engineers Nice to Have Azure cloud experience, including App Services, Azure Functions, Azure SQL, Azure API Management, Azure Service Bus, Azure VMs, Cosmos DB, or Azure Storage AWS or other cloud platform experience Experience with .NET 8, .NET 9, or modern Microsoft application modernization efforts Exposure to React or ASP.NET front-end development Experience in financial services or another regulated industry Experience leading technical design reviews or guiding engineering standards Compensation & Benefits Base salary up to $150,000, depending on experience 10% bonus opportunity 401(k) with employer match Generous PTO If you are a senior backend .NET engineer who enjoys modernization work, API design, and building reliable systems in a high-quality engineering environment, we would welcome the opportunity to connect. Determining compensation for this role (and others) at Vaco/Highspring depends upon a wide array of factors including but not limited to the individual's skill sets, experience and training, licensure and certifications, office location and other geographic considerations, as well as other business and organizational needs. With that said, as required by local law in geographies that require salary range disclosure, Vaco/Highspring notes the salary range for the role is noted in this job posting. The individual may also be eligible for discretionary bonuses, and can participate in medical, dental, and vision benefits as well as the company's 401(k) retirement plan. Additional disclaimer: Unless otherwise noted in the job description, the position Vaco/Highspring is filing for is occupied. Please note, however, that Vaco/Highspring is regularly asked to provide talent to other organizations. By submitting to this position, you are agreeing to be included in our talent pool for future hiring for similarly qualified positions. Submissions to this position are subject to the use of AI to perform preliminary candidate screenings, focused on ensuring minimum job requirements noted in the position are satisfied. Further assessment of candidates beyond this initial phase within Vaco/Highspring will be otherwise assessed by recruiters and hiring managers. Vaco/Highspring does not have knowledge of the tools used by its clients in making final hiring decisions and cannot opine on their use of AI products. EEO Notice Vaco by Highspring is an Equal Opportunity Employer and does not discriminate against any employee or applicant for employment because of race (including but not limited to traits historically associated with race such as hair texture and hair style), color, sex (includes pregnancy or related conditions), religion or creed, national origin, citizenship, age, disability, status as a veteran, union membership, ethnicity, gender, gender identity, gender expression, sexual orientation, marital status, political affiliation, or any other protected characteristics as required by federal, state or local law. Vaco by Highspring and its parents, affiliates, and subsidiaries are committed to the full inclusion of all qualified individuals. As part of this commitment, Vaco by Highspring and its parents, affiliates, and subsidiaries will ensure that persons with disabilities are provided reasonable accommodations. If reasonable accommodation is needed to participate in the job application or interview process, to perform essential job functions, and/or to receive other benefits and privileges of employment, please contact View email address on click.appcast.io . Vaco by Highspring also wants all applicants to know their rights that workplace discrimination is illegal . Representation Notice By submitting to this position, you agree that you will be giving Vaco by Highspring the exclusive right to present your as a candidate for the foregoing employment opportunity. You further agree that you have represented information about yourself accurately and have not affirmatively misrepresented your qualifications. You also agree to maintain as confidential, to the fullest extent permitted by law, any information you learn from Vaco by Highspring about the position and you will limit disclosure of information about the position only to the extent necessary to perform any obligations in furtherance of your application. In exchange, Vaco by Highspring agrees to exercise reasonable efforts to represent you through all solicitation, job screening and resume dispersal. For residents of Ontario, Canada: Based on Highspring's discussions with its Client, Highspring's understanding is that this position for employment is a current vacancy (either through Highspring as a contractor or with the client directly). Privacy Notice Vaco by Highspring and its parents, affiliates, and subsidiaries ("we," "our," or "Vaco by Highspring") respects your privacy and are committed to providing transparent notice of our policies. California residents may access Vaco by Highspring HR Notice at Collection for California Applicants and Employees here . Virginia residents may access our state specific policies here . Residents of all other states may access our policies here . Canadian residents may access our policies in English here and in French here . Residents of countries governed by GDPR may access our policies here . Additionally, submissions to this position are subject to the use of AI to perform preliminary candidate screenings, focused on ensuring minimum job requirements noted in the position are satisfied. More details about Vaco by Highspring's use of AI can be found here ( ). Further assessment of candidates beyond this initial phase will be conducted by recruiters and hiring managers. Vaco by Highspring does not know and cannot opine on if its client's use of AI products in hiring. Pay Transparency Notice Determining compensation for this role (and others) at Vaco by Highspring depends upon a wide array of factors including but not limited to: the individual's skill sets, experience and training; licensure and certification requirements; office location and other geographic considerations; other business and organizational needs. With that said, as required by local law, Vaco by Highspring believes that the following salary range referenced above reasonably estimates the base compensation for an individual hired into this position in geographies that require salary range disclosure. The individual may also be eligible for discretionary bonuses. Vaco