First, I see you asked "how can I get them to see things my way" not "how I can see things their way/am I missing something." There's a chance it's more efficient than you realize. At least believing this possibility will help your interactions. Because then you won't come across as a know-it-all. (Not saying you do come across that way, but you might.) So approach from a perspective of you learning.
On that note people usually don't want to understand what you have to say until you understand what they have to say. So make sure you explicitly understand, then paraphrase, etc., so that people know you understand them.
To not sound like a superior - don't view yourself that way. That's probably the most important part. If you view yourself as superior, it will come out subtly in your emotions - little things you say and do. I could give you specific tips but that would just be masking the problem. View yourself truly as an equal and the right subtle behavior will flow out from you.
How to approach depends on the scope of the inefficiencies.
Case 1 - The inefficiencies directly affect you. To address these, first talk to the developer(s) about it. If that doesn't work, talk to your manager about it. Make a succinct compelling case. Since it affects your work, keep pushing until you are not negatively impacted.
Case 2 - The inefficiencies do not directly affect you.
I could be wrong, maybe it's impossible. Some people might be completely complacent in their work. They might not care to grow or change. Even if you're right. (Maybe they're threatened by someone who knows better than them - or maybe they have everything they want - who knows.) It's healthy to accept this possibility. If you force people to change, you might resort to manipulative or controlling behavior. It may work, but it's not ideal. Instead, accept that some things are beyond your control.
Your best bet is to either gain formal authority - management - or informal authority by building relationships with people.
To gain formal authority, present a compelling business case to management. Give them a problem, your solution, and how it achieves the goals/mission/objectives of the business. (Therefore learn what they are first.) They probably care about money, so make sure the focus is on their bottom-line. There's a lot more to be said, but if you need a lot of help here maybe you're not ready for management.
To gain informal authority, approach people who want to be helped. Be sure to be encouraging and not overly critical. I could say a lot here, too, but there's so much, so I'll just give the general principle: basically act in the benefit of their interests, and not your interests (I guess more accurately act in the intersection of the two). Once you've done this people will solicit your advice and follow it. Of course you have to keep acting in their interest.
Honestly, if you think know better than most of the people in a big company, you should seriously consider working for a startup or starting your own company. You'll probably be happier. While you can influence large organizations from the bottom, it's easier to effect change from the top.