Senior C# Developer

We are seeking a Senior Engineer to join our team and contribute to the design and delivery of features within a large, long-standing .NET product. In this role, you will collaborate with other senior developers to transform rough briefs into fully functional screens, application code, database changes, and optimized queries, ensuring timely delivery. You will take full ownership of features—from conceptualization through production support—leveraging AI tools like Cursor and Claude to enhance development efficiency. Every change you merge will be your responsibility in production.

Key Responsibilities
- Own features end-to-end, including interaction design, screen development, business logic, data modeling, and query optimization to deliver reliable user experiences.
- Write and maintain production C# code, ensuring stability, architectural consistency, and continuous improvement of the codebase.
- Bridge the .NET host and embedded web screens by managing messaging between C# and JavaScript, synchronizing data flow, and maintaining UI consistency.
- Design and implement database components such as tables, indexes, migration scripts, and query tuning to handle real-world data volumes effectively.
- Develop and maintain operational reports and exports, including grids, formatted documents, and spreadsheets.
- Support background processing and manage releases across live customer environments.
- Utilize AI coding tools responsibly by crafting precise prompts, reviewing all code changes thoroughly, and only shipping code you fully understand.
- Introduce AI features selectively, ensuring data privacy by avoiding customer or personal data in prompts, logs, or third-party tools.
- Provide accurate estimates based on code analysis, prioritize work to deliver usable increments early, and communicate risks promptly to manage scope and meet deadlines.

Required Qualifications
- Strong, current production experience with C# and .NET, including object-oriented design and writing maintainable code for senior-level teams.
- Proven problem-solving skills to clarify ambiguous briefs, identify constraints in code and data, and deliver functional solutions.
- Proficiency in frontend technologies such as HTML, CSS, and JavaScript to design and build embedded web screens that are responsive and consistent with the .NET interface.
- Solid backend development experience in C# for business logic, data access, and hosting embedded screens.
- Expertise in SQL Server, including schema and index design, query tuning, execution plan analysis, and writing safe migration scripts.
- Practical experience with Azure services relevant to .NET applications, ensuring secure handling of secrets and customer data outside code, logs, and AI prompts.
- Daily use of GitLab for branching, merge requests, and code reviews.
- Strong communication skills to clearly explain designs, risks, and timelines both in writing and within the team, enabling proactive decision-making.

Preferred Qualifications and Benefits
- Experience working on large Windows Forms applications and modernizing legacy .NET systems with integrated web screens.
- Ability to analyze poor execution plans, add appropriate indexes, and rewrite report queries without altering results.
- Familiarity with AI-assisted coding tools, maintaining discipline to align generated code with product standards and performing thorough reviews.
- Track record of delivering complete releases, including managing regressions, data fixes, and final user requirements before go-live.
- Good security practices, ensuring credentials are excluded from source code and logs, and handling customer and personal data in compliance with regulations.
- Additional advantages include experience with education or student-information systems, reporting, document generation, messaging, file storage in .NET, performance tuning for large reporting databases, background job processing, and automated testing where applicable.

Work Environment and Benefits
You will join a team of senior developers with significant autonomy over design and implementation decisions within your domain. New development follows established product patterns, while legacy areas receive careful, incremental improvements. The team values early communication of risks to avoid surprises and prefers scope adjustments over missed deadlines.

This role offers ownership of meaningful features in a product with real users and long-term value, collaboration with experienced senior colleagues, and the use of modern AI-assisted tools as part of everyday work.