Learn English – Word/phrase for “time-wise in-between”

Dinner is considered to be the "main" or largest meal of the day. Whether it takes place at noon or in the evening is mostly a cultural thing. For instance, many people who grew up in the American South and/or on farms traditionally ate larger meals at noontime to give them the strength to keep working through the afternoon.

Supper is more specifically a lighter evening meal. Rooted in the word "to sup", it comes, again, from farming traditions — many farming families would have a pot of soup cooking throughout the day, and would eat it in the evening — specifically, they would "sup" the soup.

Lunch is almost the midday equivalent of supper — it's also a lighter and less formal meal than Dinner, but is used specifically when referring to a midday meal. So whether you use lunch/dinner or dinner/supper is heavily determined by when your culture traditionally has its largest meal.

Much Later Edit: I happened across this article discussing the agricultural roots of midday dinner and evening supper, just to add a bit more to the conversation.

I would use the adjective "competent", which means "efficient or capable" without implying a high degree of expertise. Therefore saying "I am a competent developer" would imply that you're pretty good and that you know what you're doing, without sounding immodest or unrealistic. I believe all native English speakers (at least in the UK) would understand exactly what you meant by the this

You can't use this as a noun though - so you need to say "I am competent" rather than "I'm a competent"