Growing as a solo dev at startup

This is truly trial by fire, but one of the best things you can do (if you believe in the company) is convince the startup to hire another engineer. You can split your work into distinct categories of proposed ownership and then eloquently describe to your boss what another engineer would do for 40+ hours a week. From there, hope they make the budget for it.

fwiw, I would never expect an intern of all people to do this, so only try it if you're feeling incredibly bold haha. This is Staff Engineer behavior.

One of the best ways to learn is with talented colleagues -- that's one of the main attractions of working at FAANG or a high-caliber startup!

Your situation makes it harder to quickly level up your skill as a software engineer. It's very odd to me that you're the solo dev as an intern. I'd imagine for something as critical as the software for a company, they'd have at least one full-time engineer, or a team of engineers.

You should deeply consider this as part of your decision to take a return offer. Even if the company is competitive with compensation, I'd strongly urge you to take a first job where you have existing people + processes to learn from.

For tracking metrics, this is a good discussion to have with your manager. How will they track success of what you've built?

• Usually, this boils down to revenue, number of users, or engagement
• If you can't reveal precise numbers due to confidentiality, you can talk about the change you led.

Related: Is it normal for a company to track performance related metrics and use it as input for promos/bonuses?