Johannesburg: Senior SQL Developer (JHB) posted by Datafin

About the Role

Datafin, a dynamic Johannesburg-based Business Process Outsourcer, is seeking a forward-thinking Senior SQL Developer to join their Operational Development team. As a key member of the team, you will help directly support the Call Centre by creating and maintaining solutions leaning heavily on SQL Server to query or manipulate data for in-house developed systems and reports.

Key Responsibilities

• Solve business problems alone and as part of the team by applying good reasoning and logic to use one or more of the following technologies: ASP.NET, C#, Web services, Web APIs and SQL programming. ML.NET would be an advantage and part of the role moving forward.
• Support the deployment of new IT systems and infrastructure.
• Diagnose problems using a logical approach and understanding of the underlying systems.
• Work individually or as part of a team on small to medium sized SQL projects to solve operational business requirements as well as data manipulation when needed.
• Create ad-hoc queries or SQL Server stored procedures, views and jobs based on user requests or to maintain, troubleshoot or improve existing SQL functionality.
• Work on large data sets in a live transactional environment with an awareness of the impact of running demanding queries and the side effects on a busy operational call centre.
• Create and maintain constraints, keys and indexes to improve performance and maintain database integrity and business rules.
• Design and maintain Excel and SSRS reports using stored procedures and views.
• Maintain or improve existing Excel reports using VBA for extended functionality.
• Query and summarise data across multiple servers and databases using linked servers.
• Work with dynamic SQL to solve difficult cross-server and cross-database queries and summaries.
• Apply AI tools such as ChatGPT, Claude, or GitHub Copilot to assist with coding, testing, documentation, and problem-solving while maintaining full ownership and understanding of the final solution.

Requirements

• A minimum of 10 years using and programming in C#, .NET and SQL.
• At least 5 of the most recent years using and programming in C#, .NET and SQL daily.
• A good understanding of SSIS, SSRS and Excel working with SQL Server over the past 3 years.
• Solid understanding of relational databases and database design.
• Excellent knowledge of the T-SQL language including use of stored procedures, triggers, views, data types, keys indexes, constraints, foreign keys, relational design and the related tools and development environments.
• Experience optimising SQL Server queries and stored procs and the use of query analyzer for tuning code.
• Very good general programming skills and a general interest in programming and development using primarily SQL Server and C# and the .NET platform.
• Demonstrated experience using AI tools to enhance development speed and quality. Ability to balance AI-generated assistance with strong personal judgment and deep technical understanding.
• Very good Excel skills as well as a good working knowledge of VBA programming in Excel.
• Sound knowledge of secure development principles.
• Knowledge of SQL environment using tracing tools.
• Experience with Python in the context of AI, APIs, or automation is a strong advantage.
• Web development experience using MVC and the following technologies: ASP.NET / .NET Core / Razor pages / Blazor.
• Knowledge and experience working with HTML, CSS and JavaScript/Typescript.
• Web Service development using .NET.
• Use of and RESTful APIs.
• Use of SOAP Web Services.
• Very logical with good understanding of basic Mathematics and Statistics.

Qualifications

Formal education/certifications: None mentioned

Salary & Benefits

Salary information not provided