#Response 200

Cache Control is not something browser sends first. It is a response header sent by the server along with the API response. Server is basically telling browser or CDN how to treat that data. Example User hits GET /api/profile Server sends profile JSON + Cache Control header Now what happens next depends on the type of Cache Control 👇 1️⃣ no-cache This does NOT mean do not cache. It means you can store the response, but before using it again you must check with the server if it is still valid. So browser keeps a copy, but every time before reuse it revalidates. Perfect for dashboards or data that changes often but not every second. 2️⃣ no-store This means do not store this response anywhere. Not in browser memory. Not on disk. Not in CDN. Used for login response, OTP verification, bank details or anything sensitive. Every single request must hit the server again. No shortcuts. 3️⃣ private This means browser can store it, but shared caches like CDN cannot. Very important for authenticated APIs like user profile. It ensures one user’s data is not cached and accidentally served to another user. 🚨Real production mistake 🚨 If you accidentally send public with max-age on an authenticated endpoint, CDN may cache it based on URL. Now imagine User A hits /api/profile CDN caches it User B hits same URL CDN serves User A’s data Boom. Data leak !!!!! Like, Share and Follow for more !! And save this reel for later :) #apis #backend #api #systemdesign

In the simplest way👇🏻 This usually happens because Postman and browsers behave differently. Browsers enforce more security rules. Here are the common reasons: 1️⃣ CORS Issue Browsers block requests from different origins. Backend must allow the frontend origin. 2️⃣ Preflight Request Browsers send an OPTIONS request first to check permissions. If the server doesn’t handle it → request fails. 3️⃣ Missing Headers Headers like Authorization or Content-Type might be sent in Postman but missing in the frontend. 4️⃣ Authentication Problem Token or cookies may not be attached properly in browser requests. 5️⃣ HTTP vs HTTPS If frontend runs on HTTPS and API is HTTP, browsers block it. 6️⃣ CSRF Protection Some backends require a CSRF token for browser requests. 7️⃣ Cookie / SameSite Policy Browsers enforce strict cookie security rules, Postman doesn’t. 8️⃣ Wrong Environment URL Frontend might be calling a different API endpoint than Postman. 🔎 How to debug: Open Browser DevTools → Network Tab → compare request with Postman → find the difference → fix backend or frontend config. 💡If you understand this, API debugging becomes much easier. Follow- @priforyou._ for more!! #backend #webdevelopment #api #backenddeveloper #softwareengineer #learning #fyp #viral #explore #systemdesign #coding #programming

🔥 𝗜𝗡𝗧𝗘𝗥𝗩𝗜𝗘𝗪𝗘𝗥: “If both GET and POST send data to a server… why is sending passwords via GET a bad idea?" 🧠 𝗕𝗘𝗚𝗜𝗡𝗡𝗘𝗥 𝗘𝗫𝗣𝗟𝗔𝗡𝗔𝗧𝗜𝗢𝗡 Imagine writing your password: • On a postcard (visible to everyone on the way) • Or inside a sealed envelope GET is like a postcard. Data is attached directly in the URL. POST is like an envelope. Data goes inside the request body. The difference isn’t just visibility in the browser. It’s where the data travels. ⚙️ 𝗧𝗘𝗖𝗛𝗡𝗜𝗖𝗔𝗟 𝗕𝗥𝗘𝗔𝗞𝗗𝗢𝗪𝗡 🔹 GET • Data is sent in the URL • Visible in browser history • Stored in server logs • Can be cached • Has length limits Used for: Fetching data only. 🔹 POST • Data is sent in request body • Not visible in URL • Not cached by default • No strict size limit Used for: Creating or modifying data. Important concept: GET is idempotent → Repeating it should not change data. POST is not idempotent → Repeating it may create duplicate actions. Sending sensitive data via GET is risky because: • URLs can be logged • URLs can be cached • URLs can be bookmarked • URLs can leak through referer headers Even over HTTPS. 🚀 𝗦𝗬𝗦𝗧𝗘𝗠 𝗟𝗘𝗩𝗘𝗟 𝗜𝗡𝗦𝗜𝗚𝗛𝗧 Security doesn’t come from POST. Security comes from HTTPS. But protocol design matters: GET = safe, read-only, cacheable POST = state-changing, not cache-friendly Wrong method choice can: • Break caching • Cause duplicate actions • Leak sensitive info It’s not about “form submission.” It’s about semantics. 🎯 𝗜𝗡𝗧𝗘𝗥𝗩𝗜𝗘𝗪 𝗙𝗟𝗘𝗫 GET transmits parameters in the URL and is designed to be safe and idempotent, while POST sends data in the request body and is intended for state-changing operations. Sensitive data should avoid GET due to logging and caching exposure risks. 🔥 𝗙𝗜𝗡𝗔𝗟 𝗧𝗥𝗨𝗧𝗛 GET asks. POST acts. Choose wisely. 👉 Follow @darpan.decoded Save this for Backend fundamentals. #coding #computerscience #systemdesign #backendlogic #javascript

Do you know what HTTP Methods are? 🤔 If you want to understand how APIs handle data, save this video now 🔖 In just 30 seconds, you’ll learn: GET – Fetch data POST – Create new data PUT & PATCH – Update data DELETE – Remove data Using the right HTTP method helps you build clean, scalable APIs and think like a real developer 💻🔥 📄 I’ve also created a free PDF on HTTP Methods. 👉 Comment “PDF” and follow the page to receive it in your DM 📩 #HTTPMethods #API #APIDevelopment #RESTAPI #WebDevelopment #Frontend #Backend #FullStackDeveloper #Coding #LearnCoding #CodingForBeginners #SoftwareDeveloper #DeveloperLife #Programming #TechShorts #YouTubeShorts #InstagramReels #ITCareer #Zendev

Comment “blog” & I’ll share the blog link & my notes with you in your DM 🤝🏻 (Make sure to follow else automation won’t work) Topic: HTTP (HyperText Transfer Protocol) Save for your future interviews 📩 #dsa #systemdesign #tech #coding #codinglife #http #webdev #api [dsa, system design, HTTP, tech]

Stop Googling error codes every time something breaks. 🛑 Here is the ultimate 101 breakdown: ✅ 400s = You made a mistake (Client side). ✅ 500s = They made a mistake (Server side). Hit SAVE so you’re ready for your next troubleshooting session! 💾 #TechTips #SoftwareEngineering #WebDesign #LearnToCode #ComputerScience

401 means authentication failure, 403 forbidden, 404 path not found, 499 client canceled the call or closed the connection. #ErrorCode #Authentication #WebDev #ErrorHandling #Debugging #TechTips

401 means authentication failure, 403 forbidden, 404 path not found, 499 client canceled the call or closed the connection. #ErrorCode #Authentication #WebDev #ErrorHandling #Debugging #TechTips

🚨Mistake: If you say “upgrade server” here… you already failed. Global latency is a system design problem. Let’s solve it properly 👇🔥 You may not see this again.. follow this first 🚀 🌍 𝗣𝗥𝗢𝗕𝗟𝗘𝗠: 𝗗𝗔𝗧𝗔 𝗜𝗦 𝗧𝗥𝗔𝗩𝗘𝗟𝗜𝗡𝗚 𝗧𝗢𝗢 𝗙𝗔𝗥 If your server is in the USA, every request from India travels thousands of kilometers. More distance = more delay. Physics beats code. ⚡ 𝗨𝗦𝗘 𝗖𝗗𝗡 (𝗖𝗢𝗡𝗧𝗘𝗡𝗧 𝗗𝗘𝗟𝗜𝗩𝗘𝗥𝗬 𝗡𝗘𝗧𝗪𝗢𝗥𝗞) Move static data closer to users. Images, JS, CSS served from nearby servers = instant speed boost. This alone can cut seconds. 📦 𝗔𝗗𝗗 𝗥𝗘𝗚𝗜𝗢𝗡𝗔𝗟 𝗦𝗘𝗥𝗩𝗘𝗥𝗦 Deploy your backend in multiple regions. USA users hit US servers. India users hit India servers. Less travel = faster response. 🔁 𝗟𝗢𝗔𝗗 𝗕𝗔𝗟𝗔𝗡𝗖𝗜𝗡𝗚 (𝗦𝗠𝗔𝗥𝗧 𝗥𝗢𝗨𝗧𝗜𝗡𝗚) Use geo-based routing. Requests automatically go to the nearest healthy server. No manual selection needed. 🧠 𝗨𝗦𝗘 𝗖𝗔𝗖𝗛𝗜𝗡𝗚 Frequently requested data should NOT hit database every time. Use Redis / in-memory cache / edge cache. Faster reads = faster APIs. 📉 𝗢𝗣𝗧𝗜𝗠𝗜𝗭𝗘 𝗣𝗔𝗬𝗟𝗢𝗔𝗗 𝗦𝗜𝗭𝗘 Smaller response = faster transfer. Remove unused fields. Compress JSON. Send only what frontend needs. 🚀 𝗣𝗥𝗢 𝗜𝗡𝗧𝗘𝗥𝗩𝗜𝗘𝗪 𝗔𝗡𝗦𝗪𝗘𝗥 Fix global latency by combining: CDN + multi-region servers + geo-routing + caching + smaller payloads. Not one trick. A full system strategy. Share it with your coding buddy ✨ 🔥 Fast APIs aren’t built. They’re architected. 👉 Follow @darpan.decoded for real system design breakdowns 💾 Save this before your next interview 🧠 Share with someone deploying global apps ⚡ This answer makes interviewers smile. Save it. #computerscience #systemdesign #backendlogic #fyp #foryou

Each method is chosen based on the action required and its impact on server data, ensuring APIs remain consistent and predictable. ➡️ GET: Retrieves data from the server without making changes. Used for reading information. ➡️ POST: Creates a new resource on the server. Ideal for submitting new entries or data. ➡️ PUT: Fully updates an existing resource. Used when replacing the entire resource. ➡️ PATCH: Partially updates a resource. Useful for making small changes without affecting other data. ➡️ DELETE: Removes a resource from the server. Used for permanently deleting data. #tech #api #softwareengineer #dev

Here’s how to approach such follow up system design question where interviewer want to understand the depth of your technical expertise. Identify the real bottleneck Cache fixes only one layer. Latency can come from network, database, serialization or third-party calls. Example: cache fetch is 5ms but network time is 300ms. Check cache hit ratio Low hit ratio means most requests still hit the database. Cold cache or wrong keys are common issues. Example: only 40 percent traffic is served from Redis. Verify cache placement Caching API responses does not fix inefficient internal queries. Example: API is cached but still executes multiple DB calls internally. Look for N plus 1 queries Multiple database calls per request kill performance and cache cannot hide bad query design. Example: one order fetch triggers ten item queries. Reduce payload size Large responses increase serialization and transfer time even when cached. Example: returning 200 fields when frontend needs 10. Check database contention Locks, missing indexes or exhausted connection pools slow requests regardless of cache. Example: reads waiting on long write transactions. Consider user location Application cache helps servers. CDN helps global users. Example: users far from your region see higher latency. Takeaway Such questions don't have a fixed answer like cache. It is one optimization in system design. 👉 Save this for interviews 👉 Share with a dev who keeps saying “just add cache” 👉 Follow for real system design breakdowns system design interview, backend performance optimization, API latency, caching strategies, distributed systems, scalable backend, database performance, web application performance #systemdesign #backendengineering #softwaredeveloper #techinterviews #developers

HTTP vs HTTPS: The Real Reason 🔐 --- In interviews, we often say “HTTPS is secure, HTTP is not” — but the real reason is rarely explained properly. In HTTP, data travels as plain text, which means anyone in between (like attackers or intermediaries) can read or intercept the packets. In HTTPS, data is protected using TLS encryption. TLS encrypts the communication between the client and the server, so even if someone captures the packets, they can’t understand the data. This video explains: • Why HTTP is insecure • How plain-text data can be read in transit • How TLS encryption makes HTTPS secure If you’re a developer, student, or preparing for interviews, this is the explanation you should actually give. Save it. Share it. Understand it. 🔐🚀 --- #HTTPS #SystemDesign #DeveloperLife #TechExplained #CodingInterview