Senior Full-Stack Engineer (.NET / ASP.NET) - Technology

ABOUT TRUELOGIC At Truelogic we are a leading provider of nearshore staff augmentation services headquartered in New York. For over two decades, we’ve been delivering top-tier technology solutions to companies of all sizes, from innovative startups to industry leaders, helping them achieve their digital transformation goals. Our team of 600+ highly skilled tech professionals, based in Latin America, drives digital disruption by partnering with U.S. companies on their most impactful projects. Whether collaborating with Fortune 500 giants or scaling startups, we deliver results that make a difference. By applying for this position, you’re taking the first step in joining a dynamic team that values your expertise and aspirations. We aim to align your skills with opportunities that foster exceptional career growth and success while contributing to transformative projects that shape the future. OUR CLIENT A leading B2B digital marketing agency JOB SUMMARY The Senior Developer is a critical individual contributor responsible for building, extending, and maintaining a secure, enterprise-grade web platform and APIs. Rather than defining technical direction or leading a team, this role requires a highly skilled developer who can deeply understand, respect, and execute within an established reference architecture (specifically a Domain-Driven Design (DDD) and Onion/Hexagonal hybrid architecture). A major focus of this role will be executing critical third-party financial workflows, heavily dictated by a J.P. Morgan Chase API integration. The ideal candidate brings a strong background in payment gateway integration, server-side rendering, and a solid understanding of data privacy and secure application practices. RESPONSIBILITIES - Build and maintain .NET 10 Web APIs using clean dependency injection and asynchronous programming. - Strictly follow pre-existing DDD and Onion/Hexagonal hybrid architectures and SOLID principles to keep the codebase decoupled. - Handle complex SQL Server transactions, optimize queries, and maintain versioned API contracts via OpenAPI/Swashbuckle. - Maintain and optimize read-heavy Razor Views, View Components, and Partials. - Utilize Tailwind CSS, HTMX, or Alpine.js for clean, responsive UI layouts. - Enforce traditional web patterns like POST-Redirect-GET (PRG) and antiforgery tokens for secure form submissions. - Own secure API integrations with enterprise payment ecosystems (e.g., J.P. Morgan Chase, Stripe, Square). - Implement strict application-level security, ensuring PII and financial data (credit card numbers) are never exposed or logged. - Safely consume cloud configurations and credentials managed via Azure Key Vault and App Services. - Write comprehensive unit, integration, and contract tests using MSTest/NUnit and Playwright. - Operate successfully as a solo individual contributor within an Azure DevOps (Agile/Kanban) framework. QUALIFICATIONS AND JOB REQUIREMENTS - Experience: 8+ years in software development, with 5+ years dedicated to .NET Core / ASP.NET http://ASP.NET Core (Web API & MVC Razor). - Modern Stack: Strong proficiency with .NET 10 and C# 14 (Async, DI). - Architecture: Proven expertise working within established DDD, Onion, or Hexagonal patterns. - Payment Gateways: Hands-on integration experience with major financial APIs (e.g., J.P. Morgan Chase, Stripe, Square). - Web Mechanics: Deep understanding of SSR, the HTTP lifecycle, antiforgery tokens, and the POST-Redirect-GET (PRG) pattern. - Data Privacy: Strict adherence to application-level security, ensuring PII and credit card data are never exposed or logged. - Database & Cloud: Strong SQL Server transaction optimization paired with Azure configuration management (App Services, APIM, Key Vault). - Execution: Proven ability to operate autonomously as a solo individual contributor within Azure DevOps (Agile/Kanban). WHAT WE OFFER - 100% Remote Work: Enjoy the freedom to work from the location that helps you thrive. All it takes is