Job Title: Senior .NET Developer

Company Name: ConEst Software Systems

Job Url: https://www.simplyhired.com/job/k5qPeSquloGqayolXl_mOISRsIwxA1WS0E9C0Hr-mmCI7R5zfWaJEw

Job Description: Senior .NET Developer (C# / WinForms / SQL Server)
ConEst Software Systems
Remote

Job Details
Permanent | Full-time
$120,000 - $165,000 a year
1 hour ago
Benefits
Health savings account
Health insurance
Dental insurance
401(k)
Flexible spending account
Paid time off
Employee assistance program
Vision insurance
401(k) matching
Life insurance
Qualifications
Application Integration
Version control
Performance tuning
C#
Git
Windows
.NET
Application development
SQL
Improving database performance
Desktop applications
Software documentation
Technical troubleshooting support
Root cause analysis
Senior level
Debugging
Full Job Description
Senior .NET Developer (C# / WinForms / SQL Server) — Desktop Performance + Reliability

Conest develops estimating and project management software used by electrical contractors and data cabling firms. We’re hiring a senior engineer to strengthen our flagship Windows desktop estimating application, used by customers ranging from small shops to high-volume organizations.

The role

This role focuses on a mature C#/.NET WinForms desktop application backed by a SQL database. You’ll partner with an experienced developer to co-own ongoing improvements, including performance at scale, reliability, and release confidence in complex, data-heavy workflows.

Primary focus: Windows desktop (WinForms) + SQL. Not a web/front-end UI role.

What you’ll do

Diagnose and improve application performance (responsiveness, large datasets, high-usage workflows)
Write, troubleshoot, and optimize SQL queries and stored procedures used in production
Debug complex issues in a legacy WinForms application and deliver durable fixes
Participate in design discussions and code reviews to improve maintainability and reduce regression bugs
Improve release quality through practical testing and disciplined changes
Support integrations with external systems/tools (data exchange and workflow connections)
Contribute to documentation/knowledge transfer so critical system knowledge isn’t trapped in one person
Must-have experience

Senior-level experience building and supporting Windows desktop business applications
Strong C#/.NET experience, including WinForms
Strong SQL skills focused on writing and troubleshooting queries and stored procedures (not DBA administration)
Proven ability to debug, fix root causes, and prevent regressions
Collaborative working style: communicates clearly, participates in reviews, and shares context effectively
Nice-to-have

Profiling and performance tuning experience (desktop and/or SQL)
Experience improving stability in legacy systems (safe refactoring, reducing recurring defects)
Familiarity with common desktop product tooling (installers, reporting tools, UI component libraries, etc.)
Experience building integrations (import/export, APIs, data connectors)
Experience with version control systems (Git)
Interview process

Our interview process includes a brief, practical C# and SQL exercise (job-relevant; completed live via screen share).

Pay: $120,000.00 - $165,000.00 per year

Benefits:

401(k)
401(k) matching
Dental insurance
Employee assistance program
Flexible spending account
Health insurance
Health savings account
Life insurance
Paid time off
Vision insurance
People with a criminal record are encouraged to apply

Application Question(s):

How many years of WinForms / Windows desktop application experience do you have?
How often do you write or maintain SQL (queries and/or stored procedures) in production systems?
Briefly describe a performance problem you diagnosed and fixed. What did you change and how did you validate improvement?
Briefly describe a complex bug you debugged in a legacy system (root cause + how you prevented recurrence).
How many years of professional C#/.NET experience do you have?How many years of professional C#/.NET experience do you have?
Work Location: Remote