Hi there Diogo from one year ago. You've just got that sweet gig at Sapo and you're super hyped to get started and build all those awesome web applications, I'm really glad for you, you'll have a blast. :)
While we're on that topic, I think it would be cool if I'd share some pointers with you, there are certainly a lot of things that would love to tell 'one year ago me', so listen up - this is going to bail you out from some major headaches.
They're not geniouses
They're just really, really smart. Your co-workers, I mean. They are not CS gods, they just know a lot more than you. So here's the first advice - listen to them closely, learn what you can from them but be aware that you're also entitled to your own opinion.
Sure, most of the time you won't even have a solid opinion on the matter. You probably haven't faced that particular problem yet (you probably will, don't worry). So just listen closely and do think about what you're told. If you happen to disagree with that opinion, formulate very well the reasons why you disagree and please have the courage to raise the subject again - they'll probably give you a hard time at first (just because), but they're cool, they'll listen and they'll make sure they throw every single one of your arguments to the ground. If they don't, congratulations you've just won that argument, give yourself a pat on your back.
Communication is paramount
Guess what, your greatest day-to-day challenge won't be code related. It will be dealing with the product management team. One thing you need to realize right now is that** they don't speak the same language that you do**. So when in doubt, just assume they're aliens and deal with the subject accordingly.
You'll loose hours of sleep because you have misinterpreted a spec. You'll loose hours of sleep because your product manager was too lazy to even write a spec. You'll loose hours of sleep because you thought you've explained the problem clearly (and your product manager went to their place without having a clue).
Assume nothing. Also be very aware that the vast majority of the time, the product manager doesn't have a clue about what they're talking about.
They have a concept, a prototype, but they haven't thought (not even remotely) about all the scenarios, about all the possibilities. You'll be able to get them with conflicting ideas or present them with a logical fallacy pretty easily (just try). Its your job to help them out turn that concept in a concrete, feasible feature - embrace this fact, don't fight it (you'll be that much productive if you do).
Finally if your product manager isn't interested explaining why they want that feature implemented (just do what I've asked kind of person), run away from that project as soon as you can. Believe me when I tell you that if you think that a bad code base is your worst nightmare, to have a uninterested product manager that sends you cryptic emails and doesn't have the availability to explain what he/she wants, that is the absolute nightmare - you'll feel no motivation whatsoever to get up from bed those days. And yeah, these kind of people also exist in Sapo.
Be consistent, be realistic. Give a precise notion of what implies to make that change. I still think that omitting what you can and cannot do is plain wrong (when I'm asked if I can do it, I still tell everyone that I can do everything - I'm that awesome). But do make them see that that small UI change that impacts your database schema and has repercussions deep within three or four domain objects, it needs time to be done. Time, is that simple - make them see the light.
Clean code matters
The deadline absolutely does not justify everything. Always remember that the code that you're writing today is the code you'll be maintaining tomorrow - there's a very thin line separating what is an acceptable shortcut from a bad decision that will shame you while the code of the project is being used.
You'll reach the conclusion that, most of the time, the fact that you're feeling compelled to not do the right thing TM, is a direct consequence of a poor design. For this reason you'll start to understand why a poor design/architecture is a much bigger and deeper problem than a bad implementation.
While we're on the design topic, I'll also warn you that you'll start valuing much more those around you that are able to turn a complex concept into an elegant, simple and modular design. Although those epic code one-liners that solve those micro-problems efficiently and elegantly are awesome, you'll understand that what makes (or breaks) a project is your team's ability to design a solution. Look around you, you have a couple of engineers (with a capital E) that are awesome at this.
Getting back at the code level per se, here are some other more specific pointers: DRY and SRP principles are really, really important (and on the vast majority of times can and should be applied). Also remember that meta- information is one of your absolute best friends - be on the lookout for places in your code that are volatile and turn that variable information into somekind of meta-information. Try not to "hard-code" anything, it'll come back later to bite you in the ass.
Choose well when to refactor
As a programmer you have a major flaw - you don't know when to refactor. Today I look at your one-year-old code and I immediately think that it could be much better. You need to shift that mindset, your code isn't and will never be perfect (right now I'm thinking that if you reach to the conclusion that your one year old code is perfect, then you haven't evolved that much during that past year). Embrace this reality.
Having said that choose wisely when to refactor (either your code or anyone else's code). When looking at a 1300 line controller, you are allowed to shrug and curse a bit - after that (and for God's sake) think long and hard before allowing that "I must refactor this" feeling to kick in.
It will take longer and it'll be harder than it seems. You'll loose days trying to refactor that hyper-mega-super-duper class that does everything (including your breakfast) and you won't be able to finish (something more important will come along). Worst than that you won't be able to justify what you have been doing for the past couple of days (if they can't see it in the UI, it didn't happen you slacker).
Common sense will help you. Does that nasty piece of code impact the application's performance? What exactly will you gain be refactoring whatever you're looking at right now (besides being able to sleep without constantly thinking that you should have implode that class)? Will you be introducing a new feature that will require that you decompose that nasty class into a more modular solution? Bottom line - don't refactor just because.
Testing your code is great, but...
Don't give in to the hype. Yeah unit/behavioral testing is great, but don't write a test for every fart you take. I know that right know you're thinking I'm wrong (I remember when I used to think that I had to test absolutely everything, one year old me).
Some code desperately needs you to write extensive tests, some code is simply not worth it. Having said that, do make an effort to write more tests - looking back I can clearly tell you that I haven't tested my code as much as I should - you'll also learn this the hard-way (you'll cut pretty much all the articles of the new Meo website in half because of some untested regexp base replaces that you'll throw against the database on the site's launch day - you'll shit yourself as you never had before).
Oh and another thing, keep in mind that you won't be able to test your code with every possible input dataset that the code will have to handle in production. As always people have a way to surprise you regarding on how creative they can be inserting new data into your application. So do try to spot places where your code has a probability to break and deal with the problem accordingly (log relevant information and guarantee that no data is lost/gets corrupted).
There'll be always someone that'll make you feel dumb, don't worry. They'll mention some ancestral design pattern book you've never heard of, or try to discuss a new technology you have absolutely no clue about - when this happens, keep doing your thing and pick up a book to learn something new (this is one of the few things that I can compliment you about).
Also if someone on your team picks up a new technology, don't get behind - that's a freaking golden opportunity to piggy back on that guy knowledge and get some sense of what they're doing, you'll even feel that you're having kind of a free ride (just by talking with the guy next to you, you'll probably save 2 hours of banging your head agains your table and cursing to whoever wrote, whatever you're trying to learn).
One 'not-so-good' aspect of what you'll be doing is that you'll work pretty much with the same technological stack for the whole year. This won't be a problem at first, you have a lot to learn about scaling an application and maintaining an infrastructure able to maintain the websites you'll be working on. But as time passes, you'll feel kind of stuck using the same tools over and over again.
So if you happen to have an opportunity to look at some Python code, do it. If you happen to have to write a small script to do whatever, write it in Python. If you have to provision a machine, go learn Puppet or Chef. Make a personal thing to break the (technological) routine.
Trust your team
Another thing that you'll learn is that is absolutely essential to trust your team. Its a very bad feeling delegating something to someone and not being
80% sure that the output will be enough (or even worse immediately get that refactor tingling feeling that we've talked about above).
If you're dealing with an hard problem, discuss it, you'll receive a lot of valuable input. When you do ask help, run things thoroughly through your mind, think really hard about you're about to ask - if you need to, write a quick prototype before asking for help.
I'm telling you this because what seems a big question to you, will probably have a very obvious solution to the guy next to you. Most of the time this will purely be a (lack of) experience thing. Try running through some already made code that might address a similar problem, before asking - you'll loose some additional time, but you won't make a fool of yourself and you might learn something else during the process.
Finally see that guy that's right next to you and pretty much wrote the whole framework you work with on a day-to-day basis. Yeah, that guy... He'll be gone. And sooner or later most of the guys you look up to will also be gone, so exploit the shit out of them while you can - absorb every piece of knowledge they have to offer before its too late. You'll learn stuff that doesn't come in your precious books and you'll learn stuff much faster.
It'll be a great year, so lay back and do your thing. You'll be A-OK (trust me on this). :)