A maxed out GS-13 (step 10) runs 130-140k depending on locality, which is new grad range for private sector tech companies. GS-15 hits the 170k threshold, but it’s rare to find technical, non-management roles at that level. (Source: The OPM pay tables for localities are publicly available, and I was a software engineer for a DoD agency for 10 years.)
I'm still not sure where you're getting 170. The max base for GS-13 is step 10 at $103,309. Adding 30% is nowhere near 170. At the upper end of GS-13 in San Diego (29.77% locality), I was making low to mid 130s. Are you including recruitment/retention incentives?