Apasionado por el desarrollo de productos de software
Ecuador 🇪🇨
Joined January 2012
- Tweets14.5K
- Following4.2K
- Followers697
- Likes60.8K
Roberth retweeted
¡Esto es absolutamente impresionante!
Un libro de texto estático de física convertido en una experiencia de aprendizaje inmersiva e interactiva en 3D.
Puedes explorar realmente los conceptos en lugar de solo leer sobre ellos.
Imagina si más libros de texto se construyeran así.
Roberth retweeted
موقع رهيب ..
اذا ودك تتعلم البرمجة و التصميم للدوائر الالكترونية بدون ما تشتري لوحة؟
موقع Arduino يشرح دورة تفاعلية مجانية في المتصفح 👇
🧪 وش فيها؟
• لوحة Arduino Uno ثلاثية الأبعاد 3D توصّل عليها المكونات وتشغّل الكود وتشوف النتيجة قدامك
• 16 درسًا وقت فحصي اليوم، من «تعرّف على اللوحة» و«شغّل LED» إلى الحساسات والمحرك والسيرفو ومشروع كامل
• بدون تسجيل، وواجهتها بالإنجليزي
🎓 لمن مفيدة؟
• للمبتدئ قبل ما يشتري عدة
• للمعلم اللي ما عنده أدوات لكل الطلاب
• تربط سطر الكود بما يصير فعليًا على اللوحة
⚠️ المحاكاة ما تغني عن لمس القطع اللكترونية
🧠 رأيي: ممتازة لتعليم الإلكترونيات للمدارس اللي ما عندها معامل، وأتمنى نشوف نسخة عربية منها @arduino
🔗 learn-arduino-red.vercel.app
(تصميم Dilum Sanjaya)
📹 @0xKapri
Roberth retweeted
Repeat just two moves, R then U, on a solved Rubik's Cube. After 105 repetitions, it's perfectly solved again.
Roberth retweeted
¿cómo escalás una app a miles de usuarios? (explicado fácil)
todo empieza con un cliente haciendo una request a un servidor. al principio, 1 solo puede alcanzar. a medida que crece el tráfico, puede empezar a saturarse.
ahí tenés 2 opciones para crecer:
1) verticalmente: le agregás CPU o RAM al servidor. tiene un techo.
2) horizontalmente: agregás más servidores para repartir el trabajo.
si elegís la segunda, aparece una pregunta: ¿qué servidor atiende cada request?
para eso necesitás un load balancer: recibe el tráfico y lo reparte entre los servidores disponibles. si detecta que A se cayó, deja de enviarle requests y las dirige a los demás.
cada servidor corre una copia de tu app. así podés atender más tráfico sin concentrar todo el trabajo en uno solo.
hasta acá, bien. ahora todos esos servidores consultan la misma base de datos. ¿qué pasa si empieza a saturarse?
además de optimizar las consultas, podés usar:
> réplicas de lectura: copias de la base que también responden consultas.
> caché: guarda temporalmente datos que se piden seguido para evitar consultar la base cada vez.
con eso reducís la carga sobre la base. también aparece otra pregunta: si un dato cambia, ¿cuándo se enteran las demás copias?
acá entra la consistencia. las réplicas y la caché pueden quedar desactualizadas por un tiempo. necesitás definir cómo se actualizan y en qué casos podés tolerar esa demora.
y hay más conceptos que entran en juego:
> colas: para procesar tareas en segundo plano.
> CDN: para servir imágenes y archivos sin cargar todo sobre tu servidor.
> rate limiting: para limitar las requests y proteger la app de sobrecargas.
> monitoreo: para entender dónde se está trabando todo.
entonces, ¿cómo escalás una app a miles de usuarios? medís qué parte está llegando a su límite y buscás cómo aliviarla: optimizando, repartiendo el trabajo o sumando capacidad.
esto es diseño de sistemas: entender cómo encajan las piezas y qué consecuencias tiene cada decisión.
y en mi opinión, cada vez es más importante.
Roberth retweeted
50 legendary internet rabbit holes you can spend hours exploring👇
1. zoom.earth — Watch the world via live satellite imagery
2. flightradar24.com — See every plane currently in the sky
3. marinetraffic.com — Track all ships at sea in real time
4. windy.com — Live map of winds and storms
5. lightningmaps.org — Watch lightning strikes hitting Earth in real time
6. earthquake.usgs.gov — Live list of recent earthquakes
7. submarinecablemap.com — Ocean cables carrying the internet
8. globalforestwatch.org — Watch forests disappear from space
9. worldometers.info — The world's statistics, second by second
10. internetlivestats.com — Current number of tweets and searches being posted
11. thetruesize.com — Compare the true sizes of countries
12. oldmapsonline.org — Maps from centuries ago
13. davidrumsey.com — Archive of 150,000 historical maps
14. openstreetmap.org — World map drawn by volunteers
15. window-swap.com — Look out the window of a random person around the world
16. virtualvacation.us — Virtual walks through cities
17. mapcrunch.com — Teleport to a random spot on Earth
18. atlasobscura.com — Catalog of the world's strangest places
19. neal.fun — Interactive knowledge experiences
20. htwins.net/scale2 — Scale journey from atom to universe (Updated HTML5 link)
21. eyes.nasa.gov — Explore the solar system in 3D
22. stellarium-web.org — Real sky map in your browser
23. apod.nasa.gov — NASA's astronomy picture of the day
24. images.nasa.gov — NASA's entire visual archive, free
25. pudding.cool — Visual articles told through data
26. ourworldindata.org — The state of the world with real data
27. gapminder.org — What we mistakenly think we know about the world
28. informationisbeautiful.net — Visualizing complex data
29. data.worldbank.org — World Bank's open data
30. data.tuik.gov.tr — Turkey's official statistics database
31. archive.org — Archive of millions of books, films, and software
32. gutenberg.org — 70,000 free books whose copyrights have expired
33. openlibrary.org — Record of every book in the world
34. loc.gov — U.S. Library of Congress digital archive
35. europeana.eu — Europe's cultural heritage archive
36. dp.la — America's digital library collection
37. artsandculture.google.com — Tour museums from home
38. rijksmuseum.nl — Download artworks in high resolution
39. wikiart.org — Archive of 250,000 artworks
40. publicdomainreview.org — Forgotten visual treasures of history
41. openculture.com — Free archive of culture and education
42. metmuseum.org — Met Museum's open collection
43. musicmap.info — Family tree of music genres
44. radiooooo.com — Pick a country and decade to listen to that era
45. listen.hatnote.com — Turn Wikipedia edits into audio
46. wikipedia.org — Random knowledge well
47. timeanddate.com — Time, sunrises, and sky events
48. sciencedaily.com — Live stream of science news
49. arxiv.org — Free preprints of scientific papers
50. observablehq.com — Visualize data with live code
Save this. You’ll definitely need some of these later. 🔖
Comment something 😊
Follow @bytecarter_x for more useful websites, AI tools & tech resources.
Roberth retweeted
Any finite sequence of numbers can be represented exactly as a combination of complex oscillations, even when the original data looks nothing like a wave.
This is the mathematics behind the Discrete Fourier Transform (DFT), one of the fundamental tools of digital signal processing.
When engineers record sound, measure vibrations, or collect data from sensors, they obtain a sequence of samples. The DFT provides a different way to represent those same measurements, using complex exponentials at discrete frequencies.
The mathematics relies on a remarkable property called orthogonality.
For N samples, the DFT uses N orthogonal complex exponentials. Each frequency component has a corresponding complex coefficient, and the complete set of coefficients contains enough information to reconstruct every original sample.
When a complex sinusoid aligns exactly with a DFT frequency bin, its contributions reinforce at that bin and cancel at the others.
When its frequency falls between bins, the finite observation window causes its contribution to spread across multiple frequencies. This is known as spectral leakage.
These properties have enormous practical value in engineering.
In audio processing, Fourier analysis helps identify frequency components and design digital filters. In mechanical engineering, it helps detect periodic vibrations in rotating machinery. In wireless communications, OFDM systems use Fourier transforms to generate and recover signals carried by orthogonal subcarriers.
The mathematics also simplifies certain computations. Circular convolution in the sample domain becomes pointwise multiplication in the frequency domain.
The Fast Fourier Transform (FFT) makes these calculations efficient by exploiting mathematical symmetries, reducing the computational work from the quadratic cost of direct evaluation to roughly N log N for standard FFT algorithms.
There is one important distinction.
The DFT preserves all the information in the original sequence of samples, but it cannot recover information already lost during sampling.
It is an exact change of mathematical representation, not a way to recover frequencies that sampling has made indistinguishable.
Roberth retweeted
𝗠𝗖𝗣 𝘃𝘀 𝗔𝗣𝗜 𝘃𝘀 𝗦𝗸𝗶𝗹𝗹𝘀.
An 𝗔𝗣𝗜 defines how software systems communicate through specific endpoints, requests, and responses. It gives applications a structured way to access data or trigger functionality in another system.
𝗠𝗖𝗣 (Model Context Protocol) standardizes how AI applications discover and interact with external tools, data, and resources. Instead of building custom integrations for every AI client, MCP servers expose capabilities through a common protocol that agents can use.
𝗦𝗸𝗶𝗹𝗹𝘀 package reusable instructions, workflows, and resources that guide agents through specific tasks. Rather than providing new connections to external systems, they give agents task-specific procedures and know-how they can load when needed.
Together, they help agents connect to systems and use those capabilities to complete tasks.
But building all these integrations and workflows from scratch takes time.
Precisely AI Studio helps builders build faster with 𝗿𝗲𝗮𝗱𝘆-𝗺𝗮𝗱𝗲 𝗔𝗜 𝗮𝗴𝗲𝗻𝘁𝘀, 𝗮𝗽𝗽𝘀, 𝗮𝗻𝗱 𝘀𝗸𝗶𝗹𝗹𝘀 𝗰𝗼𝗻𝗻𝗲𝗰𝘁𝗲𝗱 𝘁𝗵𝗿𝗼𝘂𝗴𝗵 𝗠𝗖𝗣. Builders can explore and test them using sample data, then bring agents and skills into their existing AI stack.
Explore Precisely AI Studio → lucode.co/precisely-ai-studi…
What else would you add?
——
♻️ Repost to help other learn AI.
🙏 Thanks to @PreciselyData for sponsoring this post.
➕ Follow me ( Nikki Siapno ) to improve at AI and system design.
Roberth retweeted
🐘 Introducing Postgres Internals in 3D.
🌟 pgrun.dev/pi
Stop reading boring diagrams. Start exploring PostgreSQL.
An interactive 3D map to understand how Postgres actually works.
100% free. Built for developers.
teapawt.net/alxshp/status/21100494…
Introducing PGSync 🐘
Real-time PostgreSQL replication. FREE. OSS
Built in Rust. 🦀
Postgres 16 / 17 / 18.
No extensions. No triggers. No complex setup.
→ snapshot
→ replicate
→ stream changes
→ track WAL
→ recover from crashes
→ resume automatically
→ keep databases in sync
~15 MB RAM during streaming.
Built for developers. Built for AI agents.
Open source.
teapawt.net/alxshp/status/21078790…
Roberth retweeted
Este libro de algoritmos y estructuras de datos es espectacular y te lo recomiendo mucho.
Muy completo, ilustraciones detalladas, con pseudo código y temas desde lo más básico a avanzado.
Disponible en PDF totalmente gratis
→ jeffe.cs.illinois.edu/teachi…
ALT Portada de Algoritmos de Jeff Erickson
ALT Ejemplo de árboles binarios de profundidad 3
ALT Ejemplo de Towers de Pisa
Roberth retweeted
舊手機免費製作一個數字加密貨幣冷錢包 實操教學不是紙上談兵 見真金白銀
冷錢包很貴，教用家裡閒置手機製作一個免費的冷錢包。
大方實際轉入以太坊並且演示如何轉出錢包，
不是紙上談兵，真金白銀，
仔細看影片仔細思考！彩蛋在哪裡？
時間戳：
00:00 如何用舊手機免費製作一個加密貨幣冷錢包
00:22 加密貨幣冷錢包熱錢包基礎知識
01:25 前提條件重置舊手機
01:46 更新到最新版本
01:56 下載Imtoken app
04:40 在另一部手機安裝app設置觀察錢包
05:57 在觀察錢包添加冷錢包
08:44 從metamask轉eth到自製的冷錢包
09:42 從自製的冷錢包轉出加密貨幣
⚠️ Ledger 发布安全警告，东南亚部分用户出现资产被盗事件！
10 月 9 日，Ledger 官方表示，正在调查东南亚部分用户的资产被盗报告。这些用户有一个共同点：他们都曾通过名为 CryptoBillis 的经销商购买 Ledger 硬件钱包。
目前调查还在进行中，具体原因尚未确认。
出于安全考虑，Ledger 已要求 CryptoBillis 暂停所有 Ledger 设备的销售和发货，并建议：
过去 90 天内从该经销商购买设备、尚未初始化的用户，暂时不要使用。
已经初始化并使用的用户，考虑将资产转移至使用全新助记词的安全硬件钱包。
如有疑问，通过 Ledger 官方客服渠道联系。
我在以往所有关于硬件钱包的视频中，都反复提醒大家：一定要通过品牌官方网站购买！
不要为了省一点钱，不要为了方便，去第三方电商平台、网店或者经销商网站购买。即使对方声称是授权经销商，我个人依然建议直接从官网下单。
硬件钱包保护的是我们的数字资产，购买渠道的安全非常重要。
Ledger 官方购买地址：
shop.ledger.com/?r=6ce1458cb…
希望大家重视这次事件，也请转发给身边正在使用硬件钱包的朋友。
Roberth retweeted
I curated 223 free physics textbooks, written by the physicists who teach the courses and shared on their own pages, university sites and open archives. No sign-up, no paywall, no pirated copies. From high school mechanics to string theory. 👇
abakcus.com/book-lists/free-…
Roberth retweeted
Tu passphrase es una capa que eleva tu custodia.
He armado este paso a paso para 30 wallets: matheybtc.github.io/Tutorial…
Cuando paso lo de Coldcard me propuse armar esto para la comunidad.
Un listado de tutoriales simples de como activar tu Passphrase BIP39.
Ya son 30 wallets, entre hardware, desktop, mobile & browsers.
Un recurso vivo, si encuentras un error (me avisas), si quieres otras opciones deja en los comentarios.
matheybtc.github.io/Tutorial…
Roberth retweeted
This is all you need for your next System Design interview.
Bookmark these 👇
github.com/liquidslr/system-…
pagefy.io/system-design/syst…
Roberth retweeted
Here are the 2 equations, my friend! (*)
The only real trick to your puzzle was uncovering that "camouflaged" right triangle.
If you want to calculate "r", you can do it yourself... that's just mechanical work.
If the mechanics get a bit tricky, no worries, you can always use a Casio calculator (you know, the symbolic math ones from over 20 years ago!).
Formulating the problem is where the real brainpower is; the rest is just putting down bricks.
Casework closed!
Tip: The result for “r” is an exact fraction: 3125 / 1000. Think about it!
(*) The two equations (this is the gold...):
a) 3^2 + (x + r)^2 = 5^2
b) 3^2 + x^2 = r^2
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