The value of improving an engineer is directly related to the fully loaded cost of an engineer, that is, salary and the overhead of employing said engineer.
Salary in 2018 for a low experience engineer doesn’t get much lower than $80,000/year while a senior engineer with 8-12 years of experience goes for about $120,000/year on average.
The overhead of employing an engineer is often measured as a multiplier. While some things such as office costs don’t scale with salary, other things such as software licenses scale much faster than salary since a more experienced and more valuable engineer is much more productive and makes more effective use of software thereby providing better returns for the employer. Thus even for an expensive engineer the overhead is at least a x1.5 multiplier for very lean companies while most go by the x2 rule of thumb.
In total, this makes the fully loaded cost of an engineer between $120,000/year to $240,000/year or $10,000/month to $20,000/month. Improving the performance of an engineer by 10% thus saves the company $1,000/month to $2,000/month or $12,000/year to $24,000/year.
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