SENIOR FULL-STACK C#/.NET DEVELOPER

Location: Querétaro, Qro., Mexico

Job Type: Full-time

Work Location: On-site

Schedule: Monday through Friday

ABOUT THE POSITION

We are seeking an experienced Senior Full-Stack C#/.NET Developer to continue

developing, supporting and improving our custom ERP and business-management

software.

The selected candidate will receive training on our business processes and how

employees use the system. The developer must be capable of learning a complex

existing application and translating business requirements into dependable software

solutions.

CURRENT TECHNOLOGY

- C#
- .NET Core and ASP.NET Core
- Microsoft SQL Server
- Microsoft Azure
- REST APIs
- Git source control

RESPONSIBILITIES

- Review and understand the existing C#/.NET application.
- Develop new features and improve existing modules.
- Diagnose and correct software bugs.
- Improve application performance, security and reliability.
- Maintain and improve the Microsoft SQL Server database.
- Write complex SQL queries and optimize database performance.
- Develop and maintain APIs and third-party integrations.
- Create reports, dashboards, PDFs and Excel exports.
- Maintain user permissions, roles and audit trails.
- Collect and analyze requirements from technical and nontechnical employees.
- Translate business requirements into functional software solutions.
- Test all changes before releasing them to users.
- Deploy application and database updates through Microsoft Azure.
- Maintain technical documentation and backup procedures.
- Support multiple projects and priorities simultaneously.
- Communicate with employees in Mexico and the United States.
- Protect company information, source code and intellectual property.

REQUIRED QUALIFICATIONS

- Bachelor’s degree in Computer Science, Software Engineering, Information
- Technology or a related field.
- Five or more years of hands-on professional software-development experience.
- Strong experience with C#, .NET Core and ASP.NET Core.
- Strong Microsoft SQL Server skills.
- Knowledge of relational databases such as Microsoft SQL Server, MySQL or Oracle.
- Experience with database design, complex queries and performance optimization.




- Experience developing and supporting multi-module business applications.
- Experience with Microsoft Azure services and application deployment.
- Experience developing and integrating REST APIs.
- Experience with JavaScript or TypeScript, HTML and CSS.
- Experience with a modern front-end technology such as Angular, React or Blazor.
- Experience with Git branches, commits and pull requests.
- Familiarity with software-development life-cycle methodologies.
- Experience collecting, documenting and analyzing software requirements.
- Knowledge of Agile and Scrum concepts.
- Strong debugging, critical-thinking and problem-solving abilities.
- Ability to understand and improve a large existing codebase.
- Ability to manage multiple projects simultaneously.
- Professional working ability in Spanish and English.

OPENAI CODEX EXPERIENCE REQUIRED

- The candidate must be highly proficient with OpenAI Codex and capable of using it as part of the daily software-development workflow.
- The candidate must demonstrate the ability to use Codex to:
- Analyze and understand an existing C#/.NET codebase.
- Investigate and correct software problems.
- Develop features from written requirements.
- Create and improve automated tests.
- Refactor existing code safely.
- Review proposed code changes.
- Work with Git branches, commits and pull requests.
- Create technical documentation.
- Identify risks or errors in AI-generated code.
- Verify, test and take responsibility for all Codex-generated work.
- Codex experience does not replace programming knowledge. The candidate must have
- strong independent development skills and be capable of recognizing and correcting
- inaccurate, inefficient or unsafe AI-generated code.

PROFESSIONAL SKILLS

- Excellent attention to detail.
- Strong communication and collaboration skills.




- Ability to explain technical information to nontechnical employees.
- Strong customer-service and teamwork skills.
- Ability to understand complex system workflows.
- Ability to determine how changes may affect other parts of the software.
- Ability to identify risks, investigate problems and recommend practical solutions.
- Ability to remain calm and professional in high-pressure situations.
- Flexibility to adapt to changing priorities and requirements.
- Strong ownership, accountability and documentation habits.
- Commitment to delivering secure, reliable and high-quality software.

PREFERRED QUALIFICATIONS

- SolidWorks API or other CAD-software integration experience.
- Experience reading bills of material and custom properties from CAD files.
- Experience with document-management systems.
- Experience with barcode scanners, printers or label-generation systems.
- Experience modernizing existing C#/.NET applications.
- Experience with Python, PowerShell or Shell scripting.
- Familiarity with organizational change management.
- Experience with automated testing and deployment processes.

TECHNICAL INTERVIEW

Selected candidates will complete a practical technical evaluation that may include:

- Reviewing and explaining a C#/.NET project.
- Identifying and correcting a software problem.
- Using OpenAI Codex to assist with developing and testing a solution.
- Writing or modifying a SQL query.
- Explaining how the change would be tested and deployed.
- Identifying risks created by the proposed change.

HOW TO APPLY

Submit your résumé through Indeed and include a brief explanation of:

- Your experience with C#, .NET Core, SQL Server and Azure.
- The types of business applications you have developed or maintained.
- How you use OpenAI Codex in your development workflow.
- An example of a difficult software problem you solved.
- Your experience gathering requirements from nontechnical users.
- Your English proficiency level.

Sueldo: $1.00 - $2.00 al mes

Ventajas:

- Estacionamiento de la empresa
- Estacionamiento gratuito
- Opción a contrato indefinido

Lugar de trabajo: Empleo presencial

📌 Senior Full Stack .Net Developer (México)
🏢 POLLUX ONE MX
📍 México