Most engineering orgs treat attrition as weather: unpleasant, unpredictable, nothing you can really do about it. But the numbers are not random, and they are not cheap. Senior engineer tenure in US tech now averages somewhere around 18 months. If your team of ten loses a senior engineer roughly every other year per person, you are not building a team. You are running a training program for your competitors.
The 18-month number and what it really costs
When a senior engineer leaves, the recruiter fee to replace them, often 20 to 25 percent of first-year base, is the part everyone sees. It is also the smallest part. The replacement takes three to four months to hire and another three to six to become productive in your codebase. During that ramp you are paying full salary for partial output, your remaining engineers absorb the gap, and the institutional knowledge about why the system is built the way it is leaves the building entirely. Add it up honestly and a single senior departure costs most of a year of that role’s salary, before the new person ships anything that matters.
Counteroffers do not fix the cause
The reflex is to fight each exit with money: a counteroffer, a retention bonus, a spot raise. Sometimes it buys a year. It rarely fixes why the person was interviewing in the first place. In a market where the next 20 percent raise is always one recruiter message away, compensation alone cannot anchor someone who has learned that the fastest way to a raise is to leave. You are bidding against a structural incentive, and you will keep paying that auction every 18 months.
The stability you are not pricing in
This is where a different talent pool changes the math quietly. Engineers in Central Europe average three to four years in a role, not eighteen months. Part of that is culture and part of it is a market that does not reward job-hopping the same way. Whatever the cause, the effect on your team is real: the person who wrote the payments service is still here to explain it two years later. Continuity compounds. The team that keeps its context outpaces the team that keeps re-explaining itself, even when the second team looks faster on paper.
Run your own number first
Before you decide attrition is just the cost of doing business, run the calculation for your own team. Take your senior count, your real replacement cost per departure, and your actual 24-month attrition rate. The figure that comes out is usually large enough to fund a deliberate change in how and where you hire. That is the point at which a stable, lower-churn engineer stops looking like a nice-to-have and starts looking like the cheaper option.
If you want to see what a longer-tenure engineering relationship looks like, and the cost comparison against your current churn, read the full cost breakdown or see who is available.