Senior Software Engineer

DocuPhase LLC • St. Petersburg, FL

125d

About The Position

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.

Requirements

• 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
• 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
• 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
• 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
• 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

Nice To Haves

• Finance Domain Experience - Strongly Preferred
• 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
• 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

Responsibilities

• Developing and maintaining large-scale invoice processing, accounts payable, and document management systems serving enterprise clients across multiple industries.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior