Software Engineer

Senior C Developer (Legacy Systems / Performance Optimization)

Remote | Full-time | B2B Contract | 

We are looking for an experienced Senior C Developer to join a project focused on optimizing the performance of a legacy data processing system.

The existing platform processes large volumes of data through ETL pipelines and loads the results into a relational database (Db2). As data volumes increase, the system experiences performance degradation.

Your main responsibility will be to identify performance bottlenecks, optimize existing C code, and improve the scalability and efficiency of data processing.

We are also open to experienced C++ developers with strong C knowledge who are comfortable working primarily with C.

Responsibilities

• Analyze and optimize existing C code in a legacy production environment.
• Identify and resolve performance bottlenecks in data processing and ETL workflows.
• Improve application performance and scalability as data volumes increase.
• Work with relational databases and SQL queries.
• Optimize multithreaded and parallel processing using Intel OpenMP and related technologies.
• Investigate CPU, memory, and database performance issues.
• Maintain and improve existing system components while ensuring stability.
• Use AI-assisted development tools, including Claude, in daily engineering workflows.
• Collaborate with an international engineering team.

Requirements

• Strong commercial experience with C programming.
• Solid knowledge of C++, with readiness to work primarily in C, is also acceptable.
• Experience with performance optimization, profiling, and debugging.
• Hands-on experience maintaining or modernizing legacy systems.
• Good understanding of multithreading, concurrency, and parallel programming.
• Experience with Intel OpenMP or comparable parallel programming technologies.
• Strong SQL skills and experience with relational databases.
• Understanding of memory management and low-level application performance.
• Experience using AI coding assistants or AI-assisted development workflows.
• English B2+/C1 — confident technical communication.

Nice to Have

• Experience with IBM Db2.
• Knowledge of Embedded SQL / SQL embedded in C.
• Experience optimizing ETL or large-scale data processing systems.
• Experience with high-volume batch processing.
• Experience with performance-sensitive enterprise applications.

Project Details

• Engagement: Full-time
• Duration: Several months
• Location: Remote, excluding Russia and Belarus
• Rate: Up to $18/hour
• Start: To be discussed

Why Join?

• Work on challenging performance engineering problems.
• Optimize a production system processing growing volumes of data.
• Apply your expertise in C, concurrency, SQL, and low-level optimization.
• Work in an engineering environment using modern AI development tools.

Interested? Apply with your CV