# Latency—Why Telegram’s CEO Just Brought It Up, and Why It’s a Big Deal 🔥 If you use Telegram regularly, you might have heard its CEO warning about latency. And you might have shrugged. But latency isn’t just a buzzword — it can make or break user experience. Let’s dig in. --- ## **What Did Telegram’s CEO Say — and Why It Matters** On a recent podcast, Pavel Durov stressed something many founders ignore: *when millions of users open your app a dozen times a day, even 50 ms of extra latency adds up*. ([LinkedIn](https://www.linkedin.com/posts/sukhad007_lex-freidmans-podcast-with-pavel-durov-activity-7387937125322809344-e8Po?utm_source=chatgpt.com)) He isn’t talking about a feature delay or UI bug — he’s talking about raw responsiveness. For a global messaging app with hundreds of millions of users, that delay turns into frustration. That is not acceptable. Durov built Telegram on two principles: privacy and real-time communication. ([Lex Fridman](https://lexfridman.com/pavel-durov-transcript/?utm_source=chatgpt.com)) If your message, notification, or chat takes noticeable time to reach the other side — the whole purpose collapses. That’s why, from him, latency is not a “nice-to-have.” It is the **core metric of trust, speed and reliability**. --- ## **What is Latency — Plain English, Expert View** In engineering, **latency** simply means the time gap between “you do something” and “the system responds.” ([Wikipedia](https://en.wikipedia.org/wiki/Latency_%28engineering%29?utm_source=chatgpt.com)) In context of chat/messaging apps (or any real-time system): * It’s the time between you hit “send” and the other side receives the message (or sees the typing indicator, or gets notified). ([Sceyt](https://sceyt.com/blog/what-is-low-latency?utm_source=chatgpt.com)) * In networking terms, it includes many small delays: * **Propagation delay** (the physical time for data to travel), ([Wikipedia](https://en.wikipedia.org/wiki/Network_delay?utm_source=chatgpt.com)) * **Transmission delay** (time to push bits onto the network), ([Wikipedia](https://en.wikipedia.org/wiki/Network_delay?utm_source=chatgpt.com)) * **Processing delay** (server or router processing), ([Wikipedia](https://en.wikipedia.org/wiki/Network_delay?utm_source=chatgpt.com)) * **Queueing or congestion delay** (when network is crowded). ([Wikipedia](https://en.wikipedia.org/wiki/Network_delay?utm_source=chatgpt.com)) When you add all these micro-delays, cumulative latency can hurt real-time feels. --- ![](https://media2.giphy.com/media/v1.Y2lkPTc5MGI3NjExYmx1cnEzaHNkdjljY3Q1ZDVkcWUzdmk2ZmFwczh3c2R6MW45MWlraSZlcD12MV9pbnRlcm5hbF9naWZfYnlfaWQmY3Q9Zw/P8ef3Dkynk0xLx1h1T/giphy.gif align="left") ## **What is “Good” Latency — How Fast Should It Be** From what engineers and real-time communication designers consider: * For chat or messaging: you want latency to be **very small — ideally so small the user doesn’t notice**. ([Sceyt](https://sceyt.com/blog/what-is-low-latency?utm_source=chatgpt.com)) * For voice/video calls or interactive apps: often target **sub-150 ms one-way** for smooth feel. ([Stream](https://getstream.io/glossary/low-latency/?utm_source=chatgpt.com)) * Above ~200 ms (or more, depending on network & load): delay becomes noticeable → leads to lag, awkwardness, or poor experience. ([Obkio](https://obkio.com/blog/what-is-good-latency/?utm_source=chatgpt.com)) In short: lower latency → faster, seamless real-time response → better user experience. --- ## **Why Low Latency Is Critical for Telegram (Or Any Real-Time Messaging App)** ### ✅ **Instant Communication — The Promise** When you send a message on Telegram: you expect it to reach instantly. No lag. No waiting. No “where did it go?”. That expectation becomes baseline when users are used to lightning-fast chats, instant replies, real-time notifications. If latency is high — even a fraction — users feel it. ### ✅ **Huge Scale — Amplifies Delay** Telegram serves **billions of users**. ([Lex Fridman](https://lexfridman.com/pavel-durov-transcript/?utm_source=chatgpt.com)) When millions of users open and exchange messages every second — even milliseconds of delay get magnified massively. Durov knows that when scale is big, the tiniest delay becomes noticeable, annoying, and harmful to user trust. ### ✅ **Reliability Under Load** At peak time, network congestion, server load, routing delays, distance — all can contribute to latency. If architecture and infrastructure are not optimized for low latency, chats delay. Notifications miss. Real-time features fail. For a privacy-centric messenger, delays kill user confidence. --- ## **What Happens When Latency Is High — The Risks & Real Effects** * **Slow message delivery** — user may see “sent” but the other user receives after delay → “Why didn’t they reply?” confusion. * **Broken real-time features** — typing indicator, message read receipts, live voice/video calls all feel laggy or fail. * **Poor user experience** — frequent delays make app feel sluggish; users may switch to faster alternatives. * **Scalability issues** — as user base grows, delays amplify, system becomes brittle, harder to maintain performance. * **Trust & reputation damage** — for an app promising privacy + speed, high latency means broken promise. --- [![](https://cdn.hashnode.com/res/hashnode/image/upload/v1764345797809/5c096c5a-4885-4e89-b96d-f65b6f065ac8.png align="center")](learnvirendana.xyz) ## **What Builders / Developers Should Learn from This** If you build any real-time system (chat, gaming, live collaboration, notifications): * Prioritize **low latency architecture**. Do not treat latency as secondary. * Optimize network: choose data-centers closer to users, efficient protocols, minimal hops. * Keep message sizes small; avoid bulky payloads for core real-time messages. ([Chronicle Software](https://chronicle.software/comparing-approaches-to-durability-in-low-latency-messaging-queues/?utm_source=chatgpt.com)) * Use scalable backend that handles peak load without queuing — because queueing introduces delay. * Monitor and benchmark **end-to-end latency** (not just server processing) — from user action to delivery. --- ## **Final Word (In My Style)** Latency — call it delay, lag, or slowdown — is the silent killer of user experience. When you build something real-time, you are not just building features. You’re building **trust, speed, responsiveness**. That’s why Pavel Durov and Telegram talk about latency. Because when you serve billions — a 50 ms lag is not negligible. It’s a **deal breaker**. If you build chat apps, gaming apps, real-time dashboards, or anything that demands instant response — don’t treat latency as “nice to have.” Treat it like **core architecture principle**. Because in real-time, if you delay — you fail. ---