A typical technical screen will be a 60 minute chat with an engineer. You will most likely use some online collaborative IDE like Coderpad, Codepen, HackerRank, etc. The crux of this interview is to complete the technical question. Although the interview is scheduled for an hour, you should only expect 45 minutes to solve the question. In general, for any technical interview you should estimate five minutes for introductions, five minutes for problem exploration and/or setup, and five minutes post-question to ask your interviewer questions about the company. That means if a technical interview is scheduled for 40 minutes you should aim to solve all the problems/parts (expect a problem to have multiple parts) in 25 minutes or less. This means you need to move fast.
For generalist/back-end roles you will most likely be asked an algorithm question. For front-end/UI roles you will likely be asked either an algorithm or UI question. Always clarify with your recruiter on what you should expect. For more information on interview types and success see Algorithm Interviews and UI Interviews
A word about introductions and post-interview questions. Although they play a minor role, both are still important. For introductions, prepare a solid two to three minute summary about your self, your experience, and your career goals. Keep in mind your narrative, the signal you convey, and your target level. For follow-up questions, prepare a list of purposeful questions you want to discuss. Your goal is to get to know the company and gather info on whether this is the right place for you. Ask what you truly want to know. The worst thing to do at this point is to say you have no questions. This communicates a lack of interest on your part. Even if you nailed the technical part, if it seems like you don't care about the opportunity you may not be passed onto the next round.
This pattern of intro, technical questions, and follow-up questions will repeat for all technical interviews, including those during the onsite. After you've done a couple live interviews you will be adjusted to the format. Post-interview, we strongly recommend you log your performance in your internal Progress document. Evaluate your performance, identify what went well and what could be done better. This is crucial for you to improve. You should be confident and near flawless by the time you screen with your top companies.
Timing-wise, We recommend you do all your screens over a two to three week period with at most one screen a day at first and potentially two to three screens in a day later on once you feel confident in your performance. Schedule your screens so that you interview with your top choices last.
If you pass the technical screen the next step is the onsite!