Sesan @code_sesan

If you’re preparing for backend engineering interviews or building scalable systems, you need to understand more than just APIs and databases. Here are 22 of the most common System Design concepts and interview questions, explained in plain English. Bookmark this thread. #SystemDesign #Backend

While both secures data, they serve different purposes. Encryption is used to prevent data access by unauthorized party. Hashing, on the other hand, is primarily used to verify data integrity and secure authentication credentials like passwords. #datasafety 🧵 4

Unlike encryption which uses key, standard hashing utilizes a salting algorithm, injecting a unique string (a salt) into the password before hashing. This ensures that identical passwords produce completely different hashes, neutralizing pre-computed dictionary attacks. 🧵 3

Why do we need to encrypt or hash data? To prevent unauthorized access. Data Encryption is a reversible process of transforming readable plaintext into ciphertext using a cryptographic algorithm and a key to prevent unauthorized access. #dataprotection #softwaredevelopment 🧵 1

@EOEboh Database indexing is column-based, mostly using the B-Tree method. How the indexed columns are ordered is very important and key to the index table been used. If the city column had been the first column of the index, that would have worked.

@SahilExec Replace the offset with cursor-based pagination

@EOEboh JWT payload is not meant for sending sensitive data,it should only be used only be used to hold one or two unique identities/data. Any sensitive data needed should be requested from the source after verifying authentication and authorization rights.

Bookmark this tweet right now. Not after reading. Now. At some point, you will build a payment system, work on one, or inherit one that is already broken. When something goes wrong, and it will, you will need exactly what I am about to show you. This is the most complete payment system breakdown I have ever written. Every flow. Every edge case. Every trap. One thread

@Hibeeka23479720 Just did

@Hibeeka23479720 @wakawaka_doctor Hi @Hibeeka23479720 I am interested, how can I get more details about study loan.

@AkinMoses1 Collaboration across borders 🚀

People get hired everyday across the globe. Most of these companies hire directly from their own job boards (ATS) And this is how to find them👇🧵

Meaning of webhooks 👁️

Difference between JWT vs Session Cookies👌💨

Late Tunde Thomas passed away after his wife revealed that her boss at FCMB, Adam Nuru, is the biological father of their two children. Tunde Thomas, known as Tunde Gentle, was 45 years old when he died approximately two weeks ago from heartbreak. It was revealed that the children he believed were his were, in fact, fathered by Adam Nuru, the current Managing Director of FCMB and Moyo Thomas's supervisor. Moyo Thomas (née Ojo) was reportedly involved in a well-known office affair with Nuru, which was common knowledge within the bank. Throughout their marriage, Tunde devoted himself to Moyo and their children, spending significantly on their wellbeing, taking them on vacations to places like London and Dubai, and enrolling them in prestigious schools. When their eldest child was around eight years old, Moyo abruptly resigned from her position at FCMB and traveled to the US with the children, claiming it was for a holiday. It was only when the new school year began in Nigeria and the children had not returned that Tunde inquired about their whereabouts. Eventually, Moyo mustered the courage to break the heartbreaking news that he was not their biological father. In a further twist, she filed for asylum in the US, alleging domestic violence against Tunde, a man recognised for his gentle and easygoing nature. Reports suggest her intention was to secure a Green Card and prevent Tunde from entering the US, thus allowing her to avoid confrontation. After learning this devastating news in 2017, Tunde reportedly suffered a stroke. Although he recovered, he emerged as a shadow of his former self, often crying unexpectedly. As he attempted to rebuild his life, he entered a new relationship with a lawyer. On December 26, he planned to visit her parents with friends. Tragically, on the night of December 15, 2020, Tunde returned home from work, c0llapsed on the staircase of his residence, and d!ed instantly. An autopsy determined the cause of his de@th as heart failure. Tunde Gentle, a former employee of the now-defunct Oceanic Bank, was laid to rest on Wednesday, December 30, 2020.. Credit Public domain

As a developer, have you asked yourself: What is the difference between Multithreading, Concurrency, and Parallelism ?

These three visualizers completely changed how I understood DSA: cs.usfca.edu - This one was incredible for seeing sorting algorithms work step-by-step on actual arrays. csvistool.com - This helped me finally understand how Stacks and Queues actually operate. visualgo.net - This is the most comprehensive one. It has everything from basic structures to advanced Graph and Tree algorithms.

Update on CVE-2025-66478 (React2Shell): An npm package has been released to scan and update affected Next.js apps. Use `npx fix-react2shell-next` to update to patched versions. All users should update as soon as possible. More details our blog: nextjs.org/cve-2025-66478