A job interview is a two way street. The employer gets to evaluate your skills and determine if you are fit for the position, and you get to evaluate the employer and decide if they would provide a satisfying job for you.
On the surface, this is easy to understand - employers will ask questions about skills, and employees typically focus on easy to understand things like what salary and benefits they will get.
Typically, most people perceive that the employer has the upper hand, and the candidate needs to always give the right answer to every question, in order to increase their odds of being hired. On the one hand, this can be a good technique for obvious reasons - it's a good thing to increase your odds of getting hired. But there's a subtle problem with focusing only on increasing your chances of getting hired - if it causes you to gloss over important considerations, or flat out lie, it's not such a good thing any more.
Simply put, you need to focus on getting the right job for you, not just on increasing your chances of getting hired by whomever you're interviewing with. You want a job that's a good fit - one where you'll be happy. Not just any job you can get an offer for.
While other answers do a good job of focusing on giving safe answers, you must always balance the value of a safe answer against being sure that your answers are accurate and meaningful for you.
I'm making this point because you said the following:
I talked freely about how I don't like my work environment - small, isolated team. I also talked quite openly about wanting to work with more up-to-date technologies. But in retrospect even these reasons can discourage people from hiring me if they think they can't provide exactly what I'm asking for.
You are correct - saying those things might mean you don't get hired by an employer who can't provide the environment you're looking for. But here's the important truth: if those things are important to you, not getting hired by that employer might be the best possible outcome.
I can't emphasize this enough: Don't be afraid of being rejected over things that are important to you. Before you proceed with your job search, do the following:
- Take a big step back. Consider the things that are actually important to you. Some people will be happy to work anywhere, as long as they're making a certain amount of money. Other people (like you, maybe) will want to work on a certain size of team, or will want to always work on the newest tech.
- Once you have your list of important factors, divide them into show stoppers and nice-to-haves.
- From that list, reverse-engineer a "company description." Pretend you're trying to advertise for companies to hire you, instead of the other way around - write our what your ideal employer looks like.
- As you apply to jobs, do research to understand if the companies you're applying to meet your requirements. Often, for softer things like culture or team size, this might be hard to determine ahead of time. But, usually, you can at least rule out some employers.
- As you are preparing for interviews, remind yourself of your must-haves and your nice to haves. When you consider how to answer questions like the one you've posed here, don't be afraid to be honest about both types of requirements.
- Take that even one step further - prepare a list of questions for the company, and make sure you at least cover your must have requirements. All too often, candidates have no serious questions ready to ask the employer. Don't be that candidate! Show that you are prepared to ask about things that are important to you.
Consider ways to phrase your answers (and your questions) that focus on the positive, show that you've done research, and show that you're a good fit. For instance, regarding your specific scenario, if you've found that a company has the characteristics you're looking for, you could say,
I left my last job because they worked in small teams and focused on tech that I didn't feel was a good fit for my skills or interests. I know from looking at your website that you've got a large dev team and you use technologies X and Y, which is what I'm really interested in.
You don't want to only speak negatively about your past employer, but it's okay (in fact, it's a good thing) to show that you decided your past employer wasn't a good fit, and it's a great thing to show that you understand specific reasons why they weren't a good fit, and you now know what will make you happy. And - it's totally excellent to show that you know that this current opportunity will offer you those things! Talk about a slam dunk!
Of course, if you don't know if this employer offers the exact things you're looking for, you can hedge your bet and give a softer answer, but make sure you're not talking yourself into a job you won't be happy with. If something is important to you, make sure it gets brought up! Yes, that may mean you don't get an offer, but unless you're desperate, that might be the best possible outcome between you and a specific employer.
Hiring managers will appreciate your honesty, and they will appreciate that you are prepared. As a hiring manager, just about the worst thing that can happen is hiring someone who is quickly unhappy - then you need to figure out what to do with an unhappy employee, which usually means you're just repeating the entire process all too soon and effectively wasting time and resources.