Senior Software Developer (.NET)

Talent Search Recruitment Consultant; Jakarta Pusat; On-site; IDR 300,000,000 - 520,000,000; Full time

Job summary

Talent Search Recruitment Consultant seeks a Senior Software Developer (.NET) to lead backend development of business-critical applications. You will design, implement, and optimize services, APIs, and data access while mentoring peers in a fast-growing telecom and network infra environment.

The role requires hands-on experience with C#, ASP.NET, REST APIs, SQL Server, and Agile practices. Opportunity to shape architecture and contribute to modernization efforts is offered.

Qualifications

• 5+ years in web apps using C# and ASP.NET.
• Strong .NET Core / .NET 6+ experience.
• Expertise in ASP.NET Core, MVC, Web API.
• Skilled in SQL Server design and query optimization.
• Experience with EF Core and REST API design.

Responsibilities

• Design, develop, test, and maintain backend services and web apps.
• Build robust REST APIs and integrate with services.
• Own features end-to-end from design to deployment.
• Work in an Agile team with sprints and reviews.
• Improve performance via caching and async patterns.

Skills

C#

ASP.NET

REST APIs

SQL Server

EF Core

Object-oriented design

Unit testing

Agile

Tools

Git

Azure

Docker

Serilog/OpenTelemetry

Job description

Our client is a growing company in the telecommunications and network infrastructure industry, providing technology-driven solutions that support connectivity and digital infrastructure. As the business continues to expand, they are looking for a Senior Software Developer (.NET) to join their technology team and take ownership of developing, enhancing, and supporting business-critical applications and services.

About the Company

Our client is a growing company in the telecommunications and network infrastructure industry, providing technology-driven solutions that support connectivity and digital infrastructure. As the business continues to expand, they are looking for a Senior Software Developer (.NET) to join their technology team and take ownership of developing, enhancing, and supporting business-critical applications and services.

About the Role

As a Senior Software Developer (.NET), you will play a key role in designing and building reliable, scalable applications and backend services. You will be involved throughout the development lifecycle, from technical design and development to deployment, performance improvement, and production support, while also contributing to technical decisions and mentoring other developers.

Key Responsibilities

• Design, develop, test, and maintain backend services and web applications using C#, .NET, and ASP.NET Core.
• Build and maintain robust REST APIs, including integration with internal and external services.
• Take ownership of features end-to-end, from technical design and development through testing, deployment, and production support.
• Work closely with the development team in an Agile environment, participating in sprint planning, estimation, code reviews, demos, and retrospectives.
• Identify and improve application performance and reliability through query optimization, caching, asynchronous programming, and API performance improvements.
• Contribute to technical and architectural decisions for new modules and the modernization of existing applications.
• Review code and provide constructive feedback to maintain high standards of code quality and engineering practices.
• Mentor and support mid-level developers, sharing technical knowledge and best practices.
• Investigate complex production issues, identify root causes, and drive issues through to resolution.
• Contribute to continuous improvement of development processes, architecture, application performance, and overall system quality.

Requirements

• 5+ years of hands-on experience developing web applications using C# and ASP.NET.
• Strong experience with .NET Core / .NET 6+, including building, deploying, and debugging applications in production.
• Strong knowledge of ASP.NET Core, MVC, and Web API.
• Strong SQL Server experience, including schema design, stored procedures, indexing, execution plans, and query optimization.
• Hands-on experience with Entity Framework / EF Core, with an understanding of when to use EF Core versus raw SQL.
• Strong experience designing and integrating REST APIs, including API versioning, error handling, and troubleshooting service-to-service failures.
• Strong understanding of object-oriented programming, SOLID principles, and common design patterns, with good judgment in applying them appropriately.
• Experience with unit and integration testing using tools such as xUnit, NUnit, or Moq.
• Strong understanding of authentication and authorization, including OAuth 2.0, OIDC, JWT, and role- or claim-based access control.
• Hands-on experience with Git, including branching strategies and pull-request workflows.
• Experience working in an Agile software development environment.
• Strong debugging, problem-solving, and analytical skills.

Strongly Preferred

• Experience with Azure, particularly App Service, SQL, Storage, Key Vault, or Service Bus; equivalent AWS experience is also relevant.
• Experience with CI/CD pipelines, such as Azure DevOps or GitHub Actions.
• Experience with Docker and container-based deployments.
• Familiarity with structured logging and observability tools such as Serilog, Application Insights, or OpenTelemetry.
• Experience with Redis or other distributed caching solutions.
• Experience with background jobs and messaging technologies such as Hangfire, Azure Service Bus, or RabbitMQ.
• Familiarity with front-end technologies such as React, Angular, or Blazor, including TypeScript.
• Experience with multi-tenant applications or SaaS architecture, including tenant isolation and per-tenant configuration.
• Experience using AI-assisted development tools, such as GitHub Copilot or Claude Code, and interest in integrating AI/LLM capabilities into product features.
• Exposure to SSRS, Power BI, ETL, or background job development.
• Experience maintaining .NET Framework 4.8 and jQuery-based applications.

What You'll Get

• Opportunity to work with a modern .NET technology stack within a growing telecommunications and network infrastructure business.
• Exposure to challenging technical projects involving application development, APIs, integrations, performance, and system modernization.
• Opportunities to contribute to technical and architectural decisions and take ownership of key modules.
• Mentorship and collaboration within an experienced technology team.
• Opportunity to mentor other developers and further develop your technical leadership capabilities.
• A collaborative Agile environment where your ideas and technical input are valued.