Sr .NET Full-Stack Developer / Technical Lead

We are looking for an experienced developer to maintain and enhance an established HR and recruitment platform covering timesheets, payroll/CPF calculations, invoicing, onboarding, and recruiter workflows.

Key responsibilities

• Develop and maintain features using C#/.NET 8, ASP.NET Core MVC, Razor, JavaScript, and jQuery.
• Translate business requirements into focused technical changes with clear acceptance criteria.
• Maintain payroll, CPF, timesheet, leave, invoicing, and recruitment logic in collaboration with business owners.
• Maintain EF Core/MySQL data access, database migrations, and MongoDB-backed dynamic schemas and workflows.
• Support Salesforce ATS and Microsoft Graph integrations, including synchronization, authentication, reconciliation, and error recovery.
• Maintain Hangfire background jobs and SignalR/Redis features; address retries, concurrency, and duplicate-processing risks.
• Diagnose production incidents, calculation discrepancies, slow queries, and integration failures.
• Coordinate releases across multiple codebases and tenant environments, including configuration management, deployment verification, rollback, and zero-downtime release procedures.
• Write and maintain automated tests, review changes, and protect existing behavior.
• Maintain authentication, permissions, audit trails, and secure handling of employee and candidate data.
• Document technical decisions, deployment procedures, operational issues, and recovery steps.
• Identify practical improvements to reliability, performance, and maintainability.

Required qualifications

• Proven experience maintaining substantial production applications using C# and ASP.NET Core MVC.
• Strong knowledge of .NET 8, Razor, dependency injection, async/await, LINQ, and MediatR/CQRS.
• Hands-on experience with EF Core, MySQL, transactions, migrations, indexing, and query optimization.
• Experience with MongoDB, including document modeling, schema evolution, aggregation, and indexing.
• Strong working knowledge of JavaScript, jQuery, HTML, CSS, AJAX, and form validation.
• Experience developing and troubleshooting REST API integrations, preferably Salesforce and Microsoft Graph.
• Understanding of OAuth/OIDC, JWT, MFA, authorization, and application security.
• Experience with Hangfire or comparable background-job systems.
• Ability to write meaningful automated tests using MSTest or equivalent frameworks.
• Proficiency with Git, code review, build/publish tooling, and release management.
• Practical experience deploying and troubleshooting .NET applications on Linux using Nginx and supervisord.
• Ability to maintain several related codebases and manage differences in configuration and behavior.
• Understanding of financial calculation accuracy, decimal precision, rounding, and traceable rule changes.

Preferred experience

• HR, recruitment, payroll, CPF, invoicing, or other compliance-sensitive applications.
• Salesforce SOQL/NetCoreForce and Microsoft Graph/Entra ID.
• Metadata-driven forms, dynamic schemas, and workflow platforms such as Ditto.
• SignalR and Redis.
• PDF/Word generation using DinkToPdf, Open XML, or MiniWord.
• Singpass or other digital-signature integrations.
• AI API integrations, structured document extraction, and secure context handling.
• DigitalOcean hosting, CI/CD pipelines, backup restoration, and disaster recovery.