I'm in a company with no senior devs I can look to for mentoring. How do you go about scaling with the company without a developer more senior to guide you during development?

I feel like I'm always second guessing decisions.

Same

Find devs in your community. I go to developer meetups and talk to other devs. One guy is helping me with learning CS better.

Trial and error

- Read books
- Never be satisfied with your code —always try to do smth better

I have news for you. You are the senior dev in this company :)

Second guessing your decisions is an extremely healthy exercise, especially when you feel you need somebody to guide you. Second guessing means lots of independent research to CYA. That's one way to become an experienced, senior-level lead that other people can rely on.

Also: experienced people who know what they're talking about also are aware that there's a lot they don't know (giving ground to second guessing). If you were going into this with no doubt nor worry at all you might be an inexperienced noob who has no business making those decisions. Look up the Dunning-Kruger Effect.

I would add, I’m the senior developer in our company. I can’t even count the number of times I’m thinking “ What da fak am I doing ? Maybe there is a better way ? Should I stop and spend 1 hour searching ? Should I keep going ?”
All part of the process !

Yeah, if you never doubt, if you're never a skeptic, then you live in a delusional fantasy world. The good thing is, it's normal and even healthy, so don't fret about it.

Welcome to the seniors club

Tl;dr : Keep gaining experience by working with the tech you use at work in your personal projects.

Im no longer a junior, but my senior left only few weeks after I joined the company. I had a lot of self taught experience in programming in general and became the "senior" in the eyes of others even though I had very little exp with the particular technologies we used. What I did to maintain this look is start my own private projects using the tech, trying out a lot of ideas on how to use it better while trying to keep it as user frendly as I can. For example I started working on a debugging/logging/profiling/testing tool that I use and still develop that helps me find performance choke points and test the code even now. I learned incredibly deep things about the techs from this project that often come in hand when others ask me for help or explanation... Just test and read a lot and you'll become the teacher, but don't forget you can also learn from other juniors

in the wild company a developer was found mentored by stackoverflow

Well, I'm the only dev in a professional game project with 15 people or so. I'm coming directly from university and I'm one year in this company. We are searching for devs; at the moment I'm programmer, maintainer, tech artist, the IT guy and more. Of course I cannot deliver the quality I want. (help)

Become senior quality developer. Easy.