Demo

Senior Software Engineer

onPhase
Clearwater, FL Full Time
POSTED ON 4/13/2026
AVAILABLE BEFORE 5/8/2026

About the Role:

We are seeking an experienced Senior Software Engineer to join our software development team working on mission-critical financial technology applications. You will be responsible for developing and maintaining large-scale invoice processing, accounts payable, and document management systems serving enterprise clients across multiple industries. The ideal candidate brings hands-on experience in financial or B2B software, with a strong understanding of AP/AR workflows, Payments systems, and broader Finance domain processes.


Finance Domain Experience - Strongly Preferred:

Given the nature of our core products — invoice processing, vendor payment management, and AP automation — we place significant value on candidates with real-world experience in:

  • Accounts Payable (AP) and/or Accounts Receivable (AR) software development or operational systems
  • Payments platforms including ACH, wire transfer, virtual card, and payment processing workflows
  • Invoice processing, purchase orders, remittance processing, and B2B document exchange (EDI)
  • Financial Technology (FinTech) products serving enterprise or mid-market clients
  • ERP integrations — SAP, Oracle, NetSuite, QuickBooks, Microsoft Dynamics, or similar platforms
  • Audit trail design, financial data integrity, and compliance-aware software development
  • Spend management, treasury operations, or general ledger (GL) system connectivity


Technical Skills:

Core .NET Technologies

  • Advanced C# and VB.NET proficiency — mixed-language enterprise codebase
  • .NET Framework 4.6–4.8 — extensive experience with legacy .NET Framework applications
  • .NET 6/7/8 — modern .NET development for new platform initiatives
  • ASP.NET Web Forms and MVC — maintain and enhance hybrid web applications
  • ASP.NET Web API — build and maintain RESTful services and integrations
  • Entity Framework — data access and ORM patterns (Code First and Database First)
  • Windows Services — background processing services for document workflow automation


Web Technologies

  • Blazor Server — build modern web UIs for SaaS platform
  • AngularJS — maintain existing frontend components
  • JavaScript/jQuery — legacy frontend maintenance with jQuery UI and validation
  • XSLT transformations — XML-based templating systems
  • Telerik UI Components — enterprise UI components for legacy and modern applications
  • OAuth 2.0 & JWT — modern API authentication and security


Database & Data Technologies

  • SQL Server — complex stored procedures, functions, and database design
  • Database-first development — schema changes, migrations, and performance optimization
  • ADO.NET — custom data access patterns and legacy integration
  • Amazon S3 — cloud document storage and management


Architecture & Integration

  • Multi-tenant SaaS architecture — customer-specific configurations and customizations
  • EDI processing — Electronic Data Interchange (810, 850, 855, 856 transaction sets)
  • File processing — CSV, XML, fixed-width file imports/exports
  • SOAP/REST web services — external system integrations
  • Payment processing integrations — financial system connectivity


DevOps & Infrastructure

  • MSBuild and Visual Studio — build automation and deployment
  • IIS deployment and management — Windows-based web application hosting
  • Git version control — large enterprise codebase management
  • PowerShell scripting — deployment and automation tasks
  • Azure DevOps Pipelines — CI/CD with YAML configurations and automated testing
  • NuGet Package Management — private Azure Artifacts feeds and dependency management


Preferred Qualifications:

  • Bachelor's degree in Computer Science or related discipline.
  • 5 years of .NET development experience
  • Finance/FinTech background — hands-on AP, AR, Payments, or financial software experience strongly preferred
  • Strong SQL Server database design and optimization skills
  • Self-motivated with ability to navigate complex, large codebases
  • Strong problem-solving skills for debugging and optimizing enterprise applications
  • Excellent communication skills for collaborating with business stakeholders and QA teams
  • Experience with legacy modernization and gradual migration strategies


Salary.com Estimation for Senior Software Engineer in Clearwater, FL
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