Sr .NET Full-Stack Developer / Technical Lead

BGC Group; Singapore; On-site; SGD 120,000 - 180,000; Full time

Job summary

BGC Group is seeking an experienced developer to maintain and enhance an HR and recruitment platform spanning timesheets, payroll, invoicing, onboarding, and recruiter workflows. You will refine logic with business owners and implement robust data access with EF Core, MySQL, and MongoDB."

Responsibilities include keeping REST integrations healthy, coordinating multi-tenant releases, and building automated tests while ensuring security, auditing, and data integrity across systems.

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.
• 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.

Responsibilities

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

Skills

C# and ASP.NET Core MVC

.NET 8, Razor, DI, async/await, LINQ,

EF Core & MySQL

MongoDB

REST API integrations

OAuth/OIDC, JWT, MFA

Hangfire

MSTest or equivalent

Git & release tooling

Linux with Nginx & supervisord

Tools

EF Core

MySQL

MongoDB

Salesforce REST

Microsoft Graph

Hangfire

SignalR

Redis

Git

Job description

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

• 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.
• 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.