The salary trajectory of a a Software Developer Engineer I ranges between locations and employers. The salary starts at £50,488 per year (estimate) and goes up to £113,665 per year (estimate) for the highest level of seniority.
The estimated average salary for a Software Developer Engineer I at CSG is £51,729 per year or £25 per hour, but some professionals have reported earning up to roughly £91,066 per year (90th percentile). The typical pay range is between £40,135 (25th percentile) and £68,481 (75th percentile) annually. This is based on 3 salaries submitted by CSG Software Developer Engineer I professionals on Glassdoor, as of Jul 2026.