It may seem old school, but a phone call is much better than an email when looking for information or following up.
Within 12 hours of any point in the interview (phone screen, submitting an assignment where applicable, and especially after on-site interviews), follow-up with a sincere thank you message. In this case, it’s suitable to use email, and send a quick thank-you note for taking time to speak with you or meet with you in person.
Once an interview stage is over and you’ve sent a thank-you note, sometimes there will be a delay in hearing from the company. Wait about a week before following up with your point of contact, but don’t be annoying about it. If you send a reminder and still don’t hear back, wait another week before sending another thank-you message, but unless your point of contact is on vacation or something, if your second response is also met with silence, it may be best to consider that job opportunity closed and to move on.
One piece of advice we give students at Turing is to follow up with a company a day after the interview to send a simple thank-you, then follow-up a week later asking for an update. Many companies will “ghost” you at this point and not even respond, but some are just busy with hiring and may overlook your message.
Keep asking for feedback or an update, but no more than once a week. Keep the tone of your message calm and upbeat. “I’m still excited about the opportunity” comes across much better than “why won’t you answer my messages?". Be sure that every follow-up message you send is uniquely written. Perhaps ask if there’s someone else within the company you can contact to get a status update.
You don’t want to be a “pest” about this follow-up though, and there is a practical limit. If you don’t hear back from them within a month or more, it’s probably not going to work out.
Just because they haven’t answered yet does not mean you should stop interviewing and wait for their response. Keep interviewing at other companies in while you wait. You can start to change your follow-up messages to something along the lines of “I’m interviewing over at ___ tomorrow. I’m still hoping to work for you, and hope to hear from you soon.”