17. TCP vs UDP

Episode 17 of 34 | System Design: From Fundamentals to Interview Mastery An original collaboration app compares reliable ordered byte streams with datagrams, including message framing, loss, deadlines, flow control, congestion, QUIC and application acknowledgements. It separates real-time media from durable edits and avoids treating UDP as automatically faster or TCP as a guarantee of eventual business success. Original script, worked examples, diagrams and animation. Adapted educational presentation; no endorsement implied. Voice generated locally with the speaker's authorization. Chapters 0:00 Welcome and what we will cover 0:11 One collaboration app has several delivery needs 1:29 TCP orders bytes, not your business operations 2:50 A missing stream segment can delay later bytes 4:09 UDP preserves datagram boundaries, not delivery guarantees 5:39 Real-time media chooses a deadline, not perfect late delivery 7:02 Flow control and congestion control solve different limits 8:17 QUIC shows why UDP does not mean unreliable application data 9:44 Choose transport by useful application outcomes 11:09 Recap, practice and thank you