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.

• 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, Dev Ops, and engineering peers in Agile delivery cycles
• Mentor junior and mid‑level engineers while helping raise engineering standards across the team

• 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

• 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

• 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.