The salary trajectory of a a Senior JavaScript Engineer ranges between locations and employers. The salary starts at $80,136 per year (estimate) and goes up to $155,156 per year (estimate) for the highest level of seniority.
The estimated average salary for a Senior JavaScript Engineer at Fullscript is $125,609 per year or $60 per hour, but some professionals have reported earning up to roughly $173,073 per year (90th percentile). The typical pay range is between $106,102 (25th percentile) and $148,702 (75th percentile) annually. This is based on 9 salaries submitted by Fullscript Senior JavaScript Engineer professionals on Glassdoor, as of Jul 2026.