Suggest me a good monitor for development

AOC Q27P1

I've been using a 24inch Dell ST2410 since 2010, still going strong. I'll endorse Dell monitors based on that experience.

27 inch, 1440p. The holistic display: if you can display most of your code on a single monitor, you'll see how everything is connected

Rather two cheap ones than one expensive. No need for fancy stuff. High(er) refresh rate can be good on the eyes, but may be troublesome with videos (e.g. sync issues of a 30Hz video on a 75Hz screen), though multiples of 60Hz won't make a problem obviously. High DPI can be good, if all the software scales well. Size depends on the distance, 24 to 27 inch are usually good.

Personally, I got one 29" 21:9 and three 23"/24" FHD monitors. The DPI is almost the same on all (0.5 margin).