The signal from a hiring standpoint is that you asked and cared about this. Engineers who will just do whatever are less useful/impactful than engineers who push back and care about the value they’re delivering. Even if it’s sometimes fuzzy to estimate.
To me it signals you're probably exaggerating. You better be able to back up your reasoning behind your claim. Bold claims require bold explanations.
It’s okay, even expected, if the answer is probabilistic. What’s not okay is doing stuff for no reason.
Bonus points if you’re able to tell a story like: We did X to achieve Y, but it didn’t work because Z. So we tried ...
We're talking about calculating the impact of your weekly or daily work directly to profit generation. There is a level of granularity and detail to your claim that is likely impossible to realistically calculate, so it would be very hard to accept such claims at face value.
Many teams don't invest in the tooling required to measure this kind of impact, but it's possible to ballpark it.
But it's 20 people working on it, from design to sales to ops to customers relations to devs. How could you possibly pin 20% of the profit (not even the turnover, but the profit) on one guy?
Even if he improved the SQL queries and that immediately led to more sales, making the choice to work on that over other things was probably not his.
It’s a team effort. Being part of the team who did X is enough. You can then talk about your specific individual contribution when appropriate.
Just like everyone in an NBA team “wins the championship” and gets to put “winner” on their resume. Or how hockey players say “I won the Stanley cup”, even though they did it as a team.
There's a big difference between:
1. I optimized SQL queries for Nameless Corp to increase profits 20%
2. I optimized SQL queries for Nameless Corp on a multi-million dollar project.
Most software devs work on tiny fragments of large projects. Let's say I work in Microsoft on Bluetooth stack in Windows 10 - how do I translate that into increased Microsoft profits?
There are definitely people who are impactful enough and deserve to make bold "I" statements but they are in the vast minority.
Also it sounds like a toxic culture if you have to constantly try to tie your day-to-day work directly to how it impacts new revenue and profits or else your work is considered worthless.