Does he like me platonically or romantically?

Start with what the conversation is about. If it is mostly logistics, memes, and shared friends, that fits both possibilities. What separates them is whether he ever steps out of the shared context to ask about you as a person on your own. A guy who is only friendly tends to keep things anchored in group plans, work gossip, or things you both are reacting to. A guy who is interested will ask what you are working on this month, what you thought of something you mentioned, or how your weekend went with you specifically in mind.

Watch for callbacks. If you mentioned a job interview or a sister's wedding two weeks ago and he brings it up unprompted, that is a strong sign he is paying attention to you rather than to the conversation as a whole. Friends remember things too, but they rarely make a point of returning to your personal details unless the friendship is already very close.

Pay attention to whether plans ever happen and who makes them. Someone who is interested in you romantically will usually be the one who moves the conversation toward meeting, and will make the suggestion concrete with a day, a place, and an activity. A friend might say you should hang out sometime and then never pin it down. That vagueness is informative.

Also notice how he behaves in person when you are alone. Does he hold eye contact, stay after the group leaves, offer to walk you to your car, or find reasons to touch your arm while talking? None of these prove anything alone, but together with the texting pattern they form a picture. If the in-person energy is consistently more relaxed and friendly without any lean toward you, that also tells you something.

If you have been watching for two or three weeks and the signals still point both ways, stop collecting data and create a clearer situation. Suggest one specific thing, like getting a drink on Thursday or seeing a film he mentioned. Keep the invitation light enough that it is easy to decline, but specific enough that his answer means something. A friend will usually say yes and suggest a group, or say he is busy. Someone interested will say yes and name a time, or ask what you had in mind.

If he declines or turns the plan into a group thing, you have your answer, and it is fine to let the energy between you cool and treat him as a friend without feeling you wasted a month. If he takes the invitation and gets more specific, you can then decide whether to say more directly that you are interested.