Senior .Net Full-Stack Engineer (with Angular or React)

N-iX is looking for a Senior .NET Full-Stack Engineer to execute security remediation and version upgrades across five applications, working with .NET, Angular/React, and Azure/AWS. The role is a 3-month engagement with potential for long-term work.

• Remediate security findings across ASP.NET (MVC, Web API, Razor Pages) codebases; every fix ships QA-validated, with tests and a rollback runbook, through the client's CI/CD.
• Execute dependency and framework upgrades (.NET Framework 4.8.1, .NET 8, EF / EF Core, React 18, Angular 20, Telerik / Kendo current release, SignalR) with regression checks; document residual gaps per component.
• Navigate and reverse-engineer legacy code - one application includes Classic ASP / VBScript tiers - to trace data and payment flows; AI-assisted code discovery is a standard part of the toolkit.
• Pair with the client's retained engineering team; knowledge coverage is uneven (one application has no SME at all), so comfort working from code rather than documentation is essential.
• Contribute evidence to the retest and closure cycle: before / after artifacts, scan diffs, deployment logs.

• 6+ years of professional .NET development on large production systems; brownfield / legacy modernization experience is mandatory — this is not a greenfield role.
• Expert C# and ASP.NET (MVC, Web API, Razor Pages); hands-on with both .NET Framework 4.5.x-era code and .NET 6+ migrations; EF / EF Core.
• Solid Angular, React and TypeScript for upgrading and stabilizing existing UIs.
• Practical experience remediating security findings (OWASP classes, secrets handling, crypto usage) in existing code; PCI / payments / fintech exposure is a strong plus.
• Azure PaaS (App Services, Functions, Service Bus, Cosmos DB); AWS (Lambda, S3, SNS/SQS); Azure AD B2C; Blazor; SignalR; Telerik / Kendo UI.

• Flexible working format - remote, office-based or flexible
• A competitive salary and good compensation package
• Personalized career growth
• Professional development tools (mentorship program, tech talks and trainings, centers of excellence, and more)
• Active tech communities with regular knowledge sharing
• Education reimbursement
• Memorable anniversary presents
• Corporate events and team buildings
• Other location-specific benefits