I am updating my resume, and I'm wondering how to quantify my contributions to a startup where I worked for ~2.5 years.
Most resume advice suggests to quantity your achievements, ie: "Boosted customer retention by 25%", "Contributed to a 12x page speed increase". Unfortunately, I didn't measure many of my achievements. I also don't think the company allowed much time for us to measure our impact.
I do have some facts, for example: I started as the 9th employee, and the 5th engineer, and we had ~10 customers. By the time I left, there were ~50 employees, ~15 engineers, and ~70 customers.
I am highlighting my achievements at the top of my resume, in the summary section. Is it okay for me to say
More than doubled active user growth at startup XYZ
? Of course I didn't do this single-handedly, but I'm not sure how else to highlight my hard work in a quantitative manner.
How do software engineers typically quantify their achievements? How bad is it to offer hand-wavy calculations?