Serverless at re:Invent 2016 – Wrap-up

The re:Invent 2016 conference was an exciting week to be working on serverless at AWS. We announced new features like support for C# and dead letter queues, and launched new application constructs with Lambda such as Lambda@Edge, AWS Greengrass, Amazon Lex, and AWS Step Functions. In addition we also added support for surfacing services built using API Gateway in the AWS marketplace, expanded the capabilities for custom authorizers, and launched a reference developer portal for managing APIs. Catch up on all the great re:Invent launches here.

In addition to the serverless mini-con with deep dive talks and best practices, we also had deep customer talks by folks from Thomson Reuters, Vevo, Expedia, and FINRA. If you weren’t able to attend the mini-con or missed a specific session, here is a quick link to the entire Serverless Mini Conference Playlist. Other interesting sessions from other tracks are listed below.

Individual Sessions from the Mini Conference

Other Interesting Sessions

Top 10 algorithms in Interview Questions

In this post “Top 10 coding problems of important  topics with their solutions ” are written. If you are preparing for a coding interview, going through these problems is a must.

Topics :
1. Graph
2. Linked List
3. Dynamic Programming
4. Sorting And Searching
5. Tree / Binary Search Tree
6. Number Theory
7. BIT Manipulation
8. String / Array

Quiet for Android – TCP over sound


org.quietmodem.Quiet allows you to pass data through the speakers on your Android device. This library can operate either as a raw frame layer or as a UDP/TCP stack.

This package contains prebuilt library files for libquiet and quiet-lwip as well as their dependencies. On top of that, it adds Java bindings which closely mimic the familiar interfaces from the* package.

This package is provided under the 3-clause BSD license. The licenses of its dependencies are also included and are licensed under a mix of BSD and MIT.

Quiet comes with support for armeabi-v7a, arm64-v8a, x86, and x86_64. It requires Android API 14 for 32-bit mode and API 21 for 64-bit mode. It requires only the RECORD_AUDIO permission.

For testing purposes, Genymotion is highly recommended over the default emulator. Genymotion provides access to the microphone while the default Android Studio one does not and will throw an exception when Quiet attempts to use the microphone.

Why sound? Isn’t that outdated?

If you are old enough, you may remember using dial-up modems to connect to the internet. In a sense, this package brings that back. While it’s true that this is somewhat of a retro approach, consider the advantages of using sound.

  • Highly cross-platform. Any device with speakers and a microphone and sufficient computational power can use this medium to communicate.
  • No pairing. Unlike Bluetooth, sound can be used instantly without the need to pair devices. This reduces the friction and improves the user experience.
  • Embeddable content. Similar to a QR code, short packets of data can be encoded into streaming or recorded audio and can then be later decoded by this package.

Programming books you might want to consider reading

There are a lot of “12 CS books every programmer must read” lists floating around out there. That’s nonsense. The field is too broad for almost any topic to be required reading for all programmers, and even if a topic is that important, people’s learning preferences differ too much for any book on that topic to be the best book on the topic for all people.

This is a list of topics and books where I’ve read the book, am familiar enough with the topic to say what you might get out of learning more about the topic, and have read other books and can say why you’d want to read one book over another.

Spying on Android events without modifying source code

Let’s say you want to intercept events in an Android app, but don’t want to modify your source code. As a simple example, you want to add logging whenever the user clicks on any button in your app. I got a bit curious about whether it was possible so I spent some time last week figuring out how this might work. This was extra fun because I’ve never written and Android app, and it’s been years since I did anything in the Java ecosystem.

Android Libraries I Wish I Knew About When I Started

There’s no sense in re-inventing the wheel when you’re working on Android apps, especially if you’re just starting out. In this 360AnDev talk, we will cover a range of libraries you can include in your Android apps that will help you tackle the problems other people have already solved. Whether you’re loading data from a web API, showing & caching images, or storing & syncing data, there’s a library you can pull in to help you out!

Kotlin null safety and its performance considerations

Kotlin may seem like a new kid on the block – itʼs been officially released only in February. Its history however dates a few years back and itʼs mature and stable enough to be used for developing solid reliable applications. Therefore at Allegro we decided to give it a chance – we built our new shiny server-side system using Kotlin as its primary language and we do not regret it.

One of the first features a Kotlin developer learns is the languageʼs approach to handling null values. It is quite interesting – especially at times like these when the most popular way of handling this problem is to use some kind of Option monad. As weʼll soon see Kotlin actually does not introduce any new special wrapper type – it uses regular Java types albeit with slight variance.

S3-compatible object storage on Cassandra

In an industry where so many people want to change the world, it’s fair to say that low cost object storage has done just that. Building a business that requires flexible low-latency storage is now affordable in a way we couldn’t imagine before.

When building the Exoscale public cloud offering, we knew that a simple object storage service, protected by Swiss privacy laws, would be crucial. After looking at the existing object storage software projects, we decided to build our own solution: Pithos.

Pithos is an open source S3-compatability layer for Apache Cassandra, the column database. In other words, it allows you to use standard S3 tools to store objects in your own Cassandra cluster. If this is the first time that you’ve looked at object storage software then you may wonder why Pithos is built on top of a NoSQL database but it’s not all that unusual.