Senior .NET Developer (Legacy Systems & Application Architecture)

Trigyn Technologies Limited.; Maharashtra; Hybrid; INR 1,800,000 - 2,400,000; Full time

Job summary

Trigyn Technologies Limited is seeking a hands-on Senior .NET Developer to own a mission-critical legacy application built on .NET Web Forms and SQL Server. This role requires someone who can operate independently, quickly build a working mental model of an existing codebase, and immediately start contributing to active development and support work - with minimal ramp-up supervision.

You'll tackle ownership of ongoing development, troubleshooting across the stack, and apply AI/automation tools

Qualifications

• 8+ years hands-on development in .NET (C#).
• Experience with ASP.NET Web Forms and jQuery.
• Strong SQL skills, stored procedures and data flow understanding.

Responsibilities

• Take ownership of ongoing development, enhancement, and support of a .NET Web Forms application with C# and jQuery.
• Analyze and troubleshoot complex issues across the stack, including the database layer.
• Independently pick up features/bugs, estimate effort, and deliver high-quality, tested code on schedule.
• Apply AI/automation tools to speed up development, testing, and support turnaround.
• Collaborate with business and technical stakeholders to clarify requirements and design decisions.
• Document system behavior and architectural decisions to reduce single-person risk.
• Flag technical debt, risks, or performance issues proactively.

Skills

.NET/C#

ASP.NET Web Forms

jQuery

SQL & Stored Proc

AI tools usage

Debugging/root-cause

Independent delivery

Stakeholder comms

Tools

Copilot

ChatGPT

Claude

Job description

Role Type: Contract
Experience: 10-15 years

About the Role

We're looking for a hands-on Senior .NET Developer to take ownership of a mission-critical legacy application built on .NET Web Forms and jQuery, backed by SQL Server. This role requires someone who can operate independently, quickly build a working mental model of an existing codebase, and immediately start contributing to active development and support work - with minimal ramp-up supervision.

Key Responsibilities

• Take ownership of ongoing development, enhancement, and support of a .NET Web Forms application with C# and jQuery.
• Analyze and troubleshoot complex technical issues across the application stack, including the database layer.
• Independently pick up assigned features/bugs, estimate effort, and deliver high-quality, tested code within committed timelines.
• Apply practical AI/automation tools (e.g., Copilot-style coding assistants, scripted automation, LLM-assisted debugging/documentation) to speed up development, testing, and support turnaround.
• Collaborate directly with business and technical stakeholders to clarify requirements and align on design decisions.
• Document system behavior and architectural decisions as understanding is built, to reduce single-person dependency risk.
• Proactively flag technical debt, risks, or performance issues in the legacy codebase.

Required Skills & Experience

• 8+ years hands-on development experience in .NET (C#), ASP.NET Web Forms, and jQuery.
• Excellent understanding of relational databases and strong SQL skills - writing/optimizing queries, working with stored procedures and functions, and reasoning about schema and data flow.
• Demonstrated ability to work independently on legacy systems with minimal documentation or handover support.
• Practical experience using AI coding/productivity tools (Copilot, ChatGPT/Claude for code review, automation scripting, etc.) in a real delivery context
• Strong debugging and root-cause analysis skills across full-stack issues.
• Proven track record of consistent, on-time, quality delivery - able to speak with specific examples.
• Strong communication skills; comfortable interfacing directly with both business and technical stakeholders.

Nice to Have

• Exposure to SSIS (ETL package development/support) and SSRS (report development/maintenance).
• Prior experience modernizing or maintaining legacy Web Forms applications.
• Exposure to system integration (APIs, third-party services, data feeds).
• General familiarity with data warehouse concepts.
• React JS (Near Future development)

What Success Looks Like in This Role

• Rapid ramp-up: functional understanding of the existing system within ~4 weeks
• Independent ownership of development/support tickets with minimal escalation.
• Measurable improvement in turnaround time on support/enhancement requests, partly through applied AI/automation practices.
• Reliable, self-driven delivery without requiring close oversight.