I know exactly what you mean, and I’ve been in your shoes. The portfolios always look perfect until you actually start working with the team. In my experience, the best filter is talking to previous clients directly (not just reading curated testimonials). That gave me a clearer idea about how companies deal with setbacks. I also suggest checking how flexible they are with scaling teams up or down, because projects rarely stay the same size from start to finish. For one of my projects, we started with just 2 developers and later needed 6, and the company we chose was able to adjust within a couple of weeks, which saved us from serious delays.

Another thing I learned the hard way: pay attention to their approach to testing and QA. Some companies rush coding and leave bugs to pile up, which ends up more expensive later. A company that insists on structured testing cycles may sound slower, but in reality it speeds up delivery because you’re not fixing things endlessly.

If you want a broader picture, this article lists some of the top Click here and explains why they stand out — not just the big names, but also firms with good niche expertise: Top 10 .NET Development Companies. I found it useful as a starting point before I even reached out to candidates.