Sunday, October 20, 2019

GitHub Markdown

GitHub Flavored Markdown Spec

in GitHub

Summary Goes Here ...this is hidden, collapsable content...
## A collapsible section with markdown
Click to expand! ```python def func(): return 'hello, world!' ```

xkcd: easy vs very hard

xkcd: Tasks

Episode #152 You have 35 million lines of Python 2, now what? - [Python Bytes Podcast]

interactive dynamic web: idyll (!)

A combination of tools and simple syntax for creating interactive web pages

Is this the dynamic web we were promised? with Parametric Press's Matthew Conlen | Hanselminutes - Fresh Talk and Tech for Developers

Idyll | A markup language for interactive and data-driven blogging.

# Hello World
[var name:"x" value:5 /]
The value of x is [Display value:x format:"d" /].
[Range value:x min:0 max:10 /]

Idyll Example Gallery

Idyll @GitHub


Unraveling The JPEG

Idyll Tutorials

Idyll Documentation | An overview.

Idyll Editor

other similar, while custom, sites/pages


Cassini's Grand Tour @ National Geographic

Exclusive: Experience the Best Dinosaur Fossil of Its Kind in 3-D @ National Geographic

Wednesday, October 16, 2019

AWS Kinesis vs. Apache Kafka

Kinesis vs. Kafka

Kinesis works with streaming data.
Kafka works with streaming data too.

Kinesis Streams is like Kafka Core.
Kinesis Analytics is like Kafka Streams.
A Kinesis Shard is like Kafka Partition.
They are similar and get used in similar use cases.

Data is stored in Kinesis for default 24 hours, and you can increase that up to 7 days.
Kafka records are by default stored for 7 days and you can increase that until you run out of disk space. In fact, you can decide by the size of the data or by date. You can even use compaction with Kafka so it only stores the latest timestamp per key per record in the log.


Tuesday, October 15, 2019

AWS: Amazon QLDB: Amazon Quantum Ledger Database

Amazon QLDB

Amazon Quantum Ledger Database (QLDB)

Fully managed ledger database that provides a transparent, immutable, and cryptographically verifiable transaction log. Owned by a central trusted authority.

Monday, October 14, 2019

Databases on AWS & Bookstore demo app

AWS re:Invent 2018: [REPEAT 1] Databases on AWS: The Right Tool for the Right Job (DAT205-R1) - YouTube

AWS re:Invent 2018: Building with AWS Databases: Match Your Workload to the Right Database (DAT301) - YouTube

aws-samples/aws-bookstore-demo-app @GitHub

AWS Bookstore Demo App is a full-stack sample web application that creates a storefront (and backend) for customers to shop for fictitious books. The entire application can be created with a single template.
High-level Architectural Diagram

  • Serverless service backend – Amazon API Gateway powers the interface layer between the frontend and backend, and invokes serverless compute with AWS Lambda.
  • Web application blueprint – We include a React web application pre-integrated out-of-the-box with tools such as React Bootstrap, Redux, React Router, internationalization, and more.
Bookstore Demo online

when you choose Athena, Aurora, RedShift, DynamoDB, RDS etc...? : aws

Relational database in general => probably Amazon Aurora

Specific relational database engine and version => Amazon RDS

Non-relational low-latency high-scale => Amazon DynamoDB

In-memory cache => Amazon Elasticache

In-memory cache for DynamoDB only => DynamoDB DAX

High-scale analytics / data warehousing => Amazon Redshift

Analytics on top of S3 Data => Amazon Athena

Analytics on top of S3 Data if already using Redshift => Redshift Spectrum

Documents with MongoDB Compatibility => DocumentDB

Sunday, October 13, 2019

Timsort : the fastest sorting algorithm

Timsort — the fastest sorting algorithm you’ve never heard of

Timsort is actually built right into Python.
To use Timsort simply write:

Original source code: check it out here.
Timsort is offically implemented in C, not Python.

Kotlin vs. Dart

a nice comparison...

The nosey programmer’s guide to Kotlin and Dart - Snapp Mobile - Medium

In Dart you need to add a semicolon at the end of each expression.
Kotlin by convention is written without a semicolon.

Dart is strongly typed.
Kotlin is statically typed.

China to require facial ID for internet and mobile

China to require facial ID for internet and mobile services - Business Insider
  • "China's 854 million internet users will soon need to use facial identification in order to apply for new internet or mobile services.
  • The Chinese government announced last month that telecommunications companies will need to scan users' faces in order to verify their identities before they can access new services.
  • The new rule will apply from December 1."
AI Weekly: In China, you can no longer buy a smartphone without a face scan | VentureBeat

Thursday, October 10, 2019

Azure Cosmos DB Jupyter notebooks

Built-in Jupyter notebooks in Azure Cosmos DB are now available | Blog | Microsoft Azure

Overview of built-in Jupyter notebooks in Azure Cosmos DB.

Azure Cosmos DB recommendations keep you on the right track | Blog | Microsoft Azure

cloud: C++, Rust, WASM on AWS Lambda; Lambda Layers

Introducing the C++ Lambda Runtime | AWS Compute Blog

Runtime API allows you to write your Lambda functions in any language, provided that you bundle it with your application artifact or as a Lambda layer that your application uses.
As an example of using this API and based on the customer demand, AWS is releasing a reference implementation of a C++ runtime for Lambda. This C++ runtime brings the simplicity and expressiveness of interpreted languages while maintaining the superiority of C++ performance and low memory footprint.

When building serverless applications, it is quite common to have code that is shared across Lambda functions. It can be your custom code, that is used by more than one function, or a standard library, that you add to simplify the implementation of your business logic.
Previously, you would have to package and deploy this shared code together with all the functions using it. Now, you can put common components in a ZIP file and upload it as a Lambda Layer. Your function code doesn’t need to be changed and can reference the libraries in the layer as it would normally do.

A function can use up to 5 layers at a time. The total unzipped size of the function and all layers can't exceed the unzipped deployment package size limit of 250 MB.

Wednesday, October 09, 2019

Engie: Car Maintenance App

app from co-founder of Waze app:

Engie - Your Car Maintenance Solution
Connecting cars with service providers worldwide

Google QUIC protocol vs TCP

QUIC - Wikipedia

"QUIC (pronounced 'quick') is a general-purpose[1] transport layer[2] network protocol initially designed by Jim Roskind at Google,[3] implemented, and deployed in 2012,[4] announced publicly in 2013

While still an Internet Draft, QUIC is used by more than half of all connections from the Chrome web browser to Google's servers. Most other web browsers do not support the protocol.

Among other applications, QUIC improves performance of connection-oriented web applications that are currently using TCP.[2][9] It does this by establishing a number of multiplexed connections between two endpoints over User Datagram Protocol (UDP). This works hand-in-hand with HTTP/2's multiplexed connections, allowing multiple streams of data to reach all the endpoints independently, and hence independent of packet losses involving other streams. In contrast, HTTP/2 hosted on Transmission Control Protocol (TCP) can suffer head-of-line-blocking delays of all multiplexed streams if any of the TCP packets are delayed or lost.

Tuesday, October 08, 2019

Salesforce: AWS vs Oracle?

Larry vs Jeff: An Epic Battle who controls Salesforce, coming at Dreamforce | LinkedIn

Salesforce infrastructure is using old versions of Oracle database, Oracle Exadata and Oracle Linux that are not autonomous.
Problem? Cost, Speed and Performance!

Saturday, October 05, 2019



"AWS IQ enables customers to quickly find, engage, and pay AWS Certified third-party experts for on-demand project work. Experts on AWS IQ can help you get projects started and completed faster by offering hands-on help for a wide range of projects, such as choosing the best architecture for your workload, automating the deployment of your infrastructure, migrating to AWS, or optimizing your AWS spend."

Electric Buses US: 300 : China 421,000

Why The US Trails China In Electric Buses - YouTube

The U.S. Has a Fleet of 300 Electric Buses. China Has 421,000 - Bloomberg

Electric bus - Wikipedia

List of electric bus makers and models - Wikipedia


AC / HVAC SEER Efficiency Savings Calculator

EnergyGuide SEER LabelSEER Efficiency Savings Calculator |

Seasonal energy efficiency ratio - Wikipedia

The efficiency of air conditioners is often rated by the seasonal energy efficiency ratio (SEER)

The SEER rating of a unit is the cooling output during a typical cooling-season divided by the total electric energy input during the same period. The higher the unit's SEER rating the more energy efficient it is. In the U.S., the SEER is the ratio of cooling in British thermal unit (BTU) to the energy consumed in watt-hours.

HVAC Installation Costs - New Air Conditioners - Modernize

SEER (Seasonal Energy Efficiency Rating) Defined

Friday, October 04, 2019

data: largest Internet companies

List of largest Internet companies - Wikipedia

RankCompanyRevenue ($B)F.Y.EmployeesMarket Cap. ($B)HeadquartersFoundedRefs
1Amazon$232.92018647,500$972.34United States Seattle1994[1][2]
2Google$120.82018103,549$791.01United States Mountain View1998[3][4]$67.22018178,000$41.99China Beijing1998[5][6]
4Alibaba$56.152201866,421$432.12China Hangzhou1999[7][8]
5Facebook$55.01201825,105$575.43United States Menlo Park2004[9][10]
6Tencent$44.67201844,796$434.66China Shenzhen1998[11][12]
7Netflix$15.820185,400$140.45United States Los Gatos1997[13][14]
8Booking$12.7201722,900$92.94United States Norwalk1996[15]
9Baidu$12.40201645,887$88.11China Beijing2000[16][17]
10eBay$10.75201814,000$34.45United States San Jose1995[18][19]$10.5201829,000$120.66United States San Francisco1999[20][21]
12Expedia$10.1201720,000$16.17United States Bellevue1996[22][23]
13Bloomberg L.P.$9.60201719,000-United States New York City1981[24]
14Uber$7.5201712,000$74.23United States San Francisco2009[25]