Back in November, I, along with some colleagues from Wingify went to Singapore to attend CSSConf and JSConf Asia. A part of DevFest Asia, it is the best way to meet and connect with front-end designers and developers in South East Asia. It was the first time CSSConf was happening in Asia, and our own Kushagra Gour had the opportunity to speak at it. He talked about 10 Commandments for efficient CSS architecture. The conference venue was Hotel Amara Sanctuary, on the island of Sentosa, Singapore.


The day began with boarding the MRT and the Sentosa Express to get to the venue, and meanwhile being mesmerized by the marvelous Singaporean skyscrapers. A sip of coffee at the Jimmy Monkey Cafe made our eyes open wide, and began Thomas’ introduction to Asia’s first CSSConf. It is commendable for a small bunch of people to organize conferences for the community at such large scale, working part time.

The quality of the talks at the conference was way above our expectations for a first-time event. The speakers and the topics they spoke about were pretty interesting. Below are the talks that I found really intriguing, and I recommend everyone to go through the videos and slides for them:

No More Tools by Karolina Szczur

Her talk made an interesting point: with all the rapid development happening in the front-end realm, we’re making use of tools more than ever, which when mixed with biases and preferences, do more harm than good. She explained what puts apart good tools from the bad ones, and the telltale signs of a tool doing more harm than good.

Build Scalable, Automated CSS Both You and Your ’Back-End’ Coders Can Love by Christian Lilley

As front-end developers, we have been conditioned to live and breathe CSS, both good and bad parts, beckoning a love-hate relationship with it. But it is rather cumbersome for someone new coming in ease into the concept of cascading style sheets, and that coupled with misused practices makes people think of CSS as some sort of dark magic. Christian’s talk separates the good parts from the bad ones, and points the listeners into a direction everyone can take to make CSS a language everyone can love.

Inside the AirBnB brand evolution by Fiona Tey

AirBnB’s product is so simple, yet efficient to use, especially their mobile app that it makes you feel a sense of satisfaction competing products or even luxurious hotels couldn’t match. Booking for a stay with the locals via AirBnB has always been exciting inspiring for me. And today it was a fortunate time to see the face behind such great product design.

What are we doing, anyway? by Ben Schwartz

If you’re like me, perhaps you ask yourself this question as the sun rises each morning. Recall a time when that wasn’t really the question? Ben’s talk took the listeners on a nostalgic ride to the years of hacking around and creating things from the past. Recall spending nights working on creating things as the first ray of sun hits the window, the pride of showing around your project in your peer group, hours upon hours of creative brainstorming to build something exciting? Ben extracts out the secret sauce for that feeling of happiness that stems from creating something and how to hold on to it to keep treading that road.

Words of Wisdom


JSConf had multitude of interesting talks. Below are the ones I found rather inspiring to attend:

Bad Form by Chris Lienert

“Your password must contain an uppercase and a lowercase letter, a number, a dinosaur’s name and your grandmother’s maiden name”: do sights of such messages make you cringe? Or perhaps you recall the frustration of filling out a large form and you missed out checking those terms and conditions and the page complains by asking you to fill everything over again? If you do, this talk will let you share your frustrations and learn about what you as a developer can do to create better forms for a better web.

Fun with JavaScript and Sensors by Jan Jongboom

In terms of what JavaScript can do on the browser and on mobile devices, Firefox OS is the best example of openness and accessibility to the lower language features. Jan, in his talk introduces several sensor APIs, primarily for Firefox OS that you could make use of to create your next big innovative app or game. Perhaps you could even mix and match the data from various sensors, or perhaps from a set of devices put together to create something awesome!

Translation Workflow and Formatting Complex Translations by Tingan Ho

Tingan goes about solving the problem of i18n and l10n by introducing concepts like CLDR, pluralization, and ICU’s message formats. He also publishes his localization module l10ns at the end of his talk. If you’re planning to translate your app into multiple languages, especially east-Asian ones, this is a must see talk.

WebTorrent by Feross Aboukhadijeh

BitTorrent is a great protocol to share data between users across the world. Feross introduces the underlying functionality of BitTorrent and the advantages of a distributed network when compared to a centralized one. He also highlights certain shortcomings of the protocol that are centralized, like torrent files and tracker servers, and how we could solve these problems. Finally he describes WebTorrent, a project that makes use of WebRTC and special “hybrid clients” to connect to the BitTorrent network.

Gibbering at Algoraves - JS in Live Audiovisual Performances by Charlie Roberts

Possess certain skills like the ability to play music and you have the chance to perform it live in front of an audience. But writing code, especially JavaScript isn’t that way. That’s what we thought before this talk. Charlie introduces Gibber, a creative coding environment that lets you create music and visuals on the fly. Be ready for a trippy ride of a JavaScript live coding performance towards the end of the talk!

It might seem like I’ve described every talk at both the events, but the truth is that the quality of the talks was so impressive that it is hard to not praise the speakers for the efforts they have put in to prepare a stellar presentation. Looking forward to the next installment of DevFest Asia in 2015!

Last week, we announced that Wingify would be sponsoring the JSFoo 2014 conference in Bangalore. We have always been looking out for opportunities to give back to the community, and what could have been better than hosting a run-up event for JSFoo in Delhi. We got in touch with HasGeek and expressed interest in hosting the Delhi run-up event. They were more than happy to let us do so.

Since it was the first time we hosted such a big event, we were both excited and nervous. We had started preparing for the event about a month in advance. To market the event, we spread out information about the event on meetup groups we were connected with, and also created a Facebook event for it. In total, we received about 100-120 signups for the event. Of all the signups, we expected about one-third of them to actually turn up for the event, for whom we started to arrange for food and logistics.

What’s exciting is that more than 50 external external guests from 30 different companies and colleges showed up. We were really humbled with such great turnout and would like to thank each one of you who joined us for the event.

The event started on time (10:30am) with Suchit Puri taking the stage. He welcomed us to the event and introduced the first speaker Rudi M.K., who was about to speak on “A new approach to scientific computing using JavaScript“. He talked about the possibilities of using JavaScript for mathematical and scientific computing. He had a few examples of using JavaScript on the server side for complex mathematical computation. It was really enlightening to see so many libraries coming up in support of scientific computing in the JavaScript ecosystem.

Rudi speaking on “A new approach to scientific computing using JavaScript”

Next was the workshop on “Learning JS concepts/techniques by implementing jQuery” from our very own Kushagra Gour . He had created a very interesting web based system specially for this workshop which he called “Prayas”. It allows the organizer to set JavaScript test cases and the participants to enter the JavaScript code which is evaluated against these test cases. It also has a very good UI which updates in real time giving you a good idea of how many of the participants have submitted in the code correctly.This made the workshop really interactive wherein the participants implemented some basic jquery methods in javascript.

Kushagra Gour taking workshop on “Learning JS concepts/techniques by implementing jQuery” with his awesome "Prayas" system on screen

The workshop was followed by lunch after which we had Shwetank Dixit talking on “Understanding WebRTC: A Whirlwind Tour”. Shwetank introduced WebRTC and then went in-depth on the topic, explaining how the technology works and how are different network related problems addressed. He also showed some really cool WebRTC demos. was one of them. We hope that attendees would have gone back and tried WebRTC.

Shwetank giving demo of WebRTC

Next was our very own Himanshu Kapoor talking on “Managing API Resources and Their Relationships on the Front-end“. This was indeed a very interesting talk wherein Himanshu talked about how we handle RESTFul resources on the front-end. The talk was primarily about our learnings of maintaining API resources and their relationships with using our internal project called ResourceManager for AngularJS (soon to be open sourced).

The last talk of the day was presented by Ankit Rastogi on “Ten Useful JavaScript Tips & Best Practices”. It was a very interesting interactive presentation on JavaScript optimizations tips and tricks. The presentation had a lot of questions which asked the audience to find whats wrong with the code, this made everyone really interested in the presentation. Everyone was really amazed by how implementing very simple things you can get many folds of processing/speed improvement in your code.

The day ended on a high note with everyone really appreciating the speakers and the organizers for all the hard work everyone put in. There were a lot of discussion after the event on organizing more such events for different communities in Delhi NCR region. Wingify as a company believes in engaging and giving back to the community and we would be more than happy to host more such events in future. If you feel that there is any technology related community which needs a place to host the event, please write to us at

Presentation slides from the event:

  1. A new approach to scientific computing using JavaScript - Rudi M. K.

  2. Learning JS concepts/techniques by implementing jQuery - Kushagra Gour

  3. Managing API Resources and Their Relationships on the Front-end - Himanshu Kapoor

  4. Ten Useful JavaScript Tips & Best Practices - Ankit Rastogi

  5. Understanding WebRTC: A Whirlwind Tour - Shwetank Dixit

Wingify Engineering on Twitter

Also, we are happy to announce that Wingify’s engineering team is now on Twitter! Follow us on @wingify_engg to get updates on awesome things being cooked here.

The front-end has become the heart of today’s web application development, and JavaScript drives a core part of it. New technologies, libraries, frameworks and the likes come up each day, and the existing ones continue to grow and evolve as time goes by. There is so much to learn, and so many learnings of your own to share, that community involvement becomes indispensable.

Our single-page application, VWO, is powered by a nifty combination of web technologies on the front-end, ranging from Grunt to AngularJS. The development process of the new version of the application was very rapid and full of challenges. We had dabbled into the previously unexplored territory of single-page application development at such a large scale, and having pulled it off in a relatively short span of time has been quite a feat.

Sponsoring JSFoo

For the very reason of community involvement being indespensable for better development, we are sponsoring JSFoo 2014 in Bangalore this year. Our engineers will be present at the conference. Should you be interested in our work, and would like to know more about what we do, want to work with us, or just want to say Hi!, drop by our booth (B1), or catch any of our team members at the event.

JSFoo Run-up Event (Delhi)

We’re also hosting a run-up event at our office in Pitampura, Delhi on 6th September 2014. There will be talks and a workshop too.

Join us at the run-up event. RSVP here.

As a part of the run-up event, we’re organising an online JavaScript competition.

Online JavaScript Competition - Visualize

The premise of this competition is simple - to use JavaScript and HTML5 canvas to create something visually appealing. The theme of the competition is Squares. You are free to create anything with JavaScript, canvas and squares.

If visualizations, particle effects, fractals, interactivity, JavaScript and canvas are some of the words that excite you, this is the competition for you. Below are some examples of JS creativity:

Below are some valid sample entries:

Making Submissions

Submissions for the competition need to be done as a deck on CSSDeck. Read here to know about submitting on CSSDeck. Optionally, you can also submit your entry via another code submission site like Codepen, or by uploading it on your server. Once you are ready with your submission, please tweet it using the following template:

I submitted an entry for Wingify-JSFoo online competition: <CSSDeck link here> @wingify @jsfooindia #wingifyjsfoocompo #js

Let the submissions begin!


  1. The deadline for the compeition is 20th September 2014, 23:59 IST.
  2. Your entry should use Javascript, HTML5 Canvas and Squares to create something visually appealing.
  3. CoffeeScript is allowed.
  4. Judgement will primarily be based on visual appeal. Secondary parameters include code quality and smoothness.
  5. Multiple entries by a single participant are allowed.
  6. Bonus points for using vanilla JS.
  7. The results will be announced after 20th September 2014 here on the blog as well as on our twitter account: @wingify.
  8. You must be living in India to be eligible for this competition.

If you have any questions or suggestions, comment on this post or send us an email.


The best two entries in the competition will be rewarded with prizes. There are three consolation prizes as well.

Winner Prize

Runner-up Prize

Consolation Prizes

  • Software licenses of Sublime Text or JetBrains WebStorm.

Wingify @ JSFoo

Our engineers will be present at the conference. If you are interested in our work, want to know more about what we are doing, want to work with us (we’re hiring), get some cool goodies or just want to say Hi!, please visit our booth (B1) or catch any of our team members. We’d love to talk to you!

We look forward to meeting in Delhi for the run-up event and in Bangalore for the conference!

Edit - 23rd September 2014

Results for our JS competition are out!

You will be contacted individually for further process. Congratulations!

DOM Comparator is a JavaScript library that analyzes and compares two HTML strings, and returns back a diff object. It returns an output which is an array of operation objects.

DOM Comparator on Github

Here’s a simple example:

var stringA = '<ul><li class="active">list item 1</li><li>list item 2</li></ul>';
var stringB = '<ul><li>list item 1</li><li>list item 2</li></ul>';

// Compare the two strings
var result = VWO.DOMComparator.create({
    stringA: stringA,
    stringB: stringB

// Expect an array of VWO.Operation objects to be returned,
// the first one of which looks like below:
    name: 'removeAttr',
    selectorPath: 'UL:first-child > LI:first-child',
    content: {
        class: 'active'


The Campaign Builder is one of the core components of our A/B testing software VWO. It allows you to make changes to any website on the fly. Assuming the target website has a small snippet of VWO Smart Code (Javascript) inserted, the changes made by the user are applied when the A/B test is run. These changes are little snippets of jQuery operations that are applied on the client-end.

One of the major problems faced when applying such changes that they did not regard for dynamic content that might have been rendered by the client’s website’s backend. Let us consider a simple example:

Imagine somebody wanting to run an A/B test on all the product pages of an eCommerce website. He wants to modify the “Buy Now” button on all such pages and make it appear bigger and bolder, so that it captures the end-user’s attention better. He navigates to some product page, selects the button and tries to edit it. Assume that that button has markup that looks like below:

<a href="javascript:addToCart(16);" class="add_to_cart">Add to Cart</a>

The Campaign Builder provides an “Edit” operation, that opens up a rich text editor for the user to make changes to any element with ease. Assuming, he makes the text of the button bolder and changes the color to a bright red, here’s what the resulting markup would look like:

<a href="javascript:addToCart(16);" class="add_to_cart" style="font-weight:bold;color:red;">Add to Cart</a>

Internally, an Edit operation is identified by the element the operation is applied on, and the new markup provided by the user, which in this case is the above code. It means that if a Buy Now button is found on any page, it will be replaced with the above code. The jQuery code for such an operation would look something like this:

// A unique selector path to identify the element
var selector = '#product_description > P:first-child + P > A:first-child';
$(selector).replaceWith('<a href="javascript:addToCart(16);" class="add_to_cart" style="font-weight:bold;color:red;">Add to Cart</a>');

Notice how this would not only add the styles to that element, but also change its href to always execute addToCart(16); regardless of the product page the user is on. Essentially, the dynamic content rendered by the client’s backend has now been replaced with static content.

DOM Comparator to the Rescue

With DOM Comparator in place, the initial markup of the Edit operation above will be compared with the final one, and a differencewould be returned. The difference would contain the minimal changes necessary to be made to the target element, thereby impacting dynamic content as less as possible.

For the above example, here’s what the list of resulting operations would look like:

    "name": "css",
    "selectorPath": "#product_description > P:first-child + P > A:first-child",
    "content": {
        "font-weight": "bold",
        "color": "red"

Live Demo

Click here to view a live demo.

What’s Next

The library is currently in a pre-alpha state. It works well for a good number of cases, but does not for a lot of others. And for certain complex cases, it might not be performant enough.

Our current plans are focused on improving the library as per the below priority list:

  • Correctness: For almost all the cases, the first priority is to get the output as correct as possible to the expectation. This has been our prime focus thus far.
  • Performance: Once we ensure the cases perform correctly, the next task is to profile and optimize for performance. Since tree comparison is a pretty complex operation, we will be looking into possibilities like spawning a worker for performing tasks, or delegating to a Node.js server for comparison.
  • Readability: For a complex algorithm, it is equally important for the code to be readable. In the coming versions, certain complex logic, especially in the classes VWO.DOMMatchFinder and VWO.StringComparator will be refactored from the point of view of readability.
  • Documentation: Writing a documentation is as hard as writing code, if not more, is what I have realized when documenting this project. Over time, we will spend some time improving the documentation, and also release a reference manual for the classes used.


If you are interested in contributing to the project, we would love to hear from you. Just fork the repository and submit a pull request.

Further Reading

Head over to the documentation if you’d like to know more.

The Fifth Elephant is a popular conference in India around the Big Data ecosystem. It happened last week in Bangalore. And we were proud to sponsor the conference. To represent Wingify at the event, Ankit, Varun and I (Vaidik) attended the event. This blog post is an account of what we did at the event and what we learned by sponsoring, attending and being present at the conference as an organization.

The conference

The organizers reported that there were 960 registrations for the conference - quite a big number for a conference around something like Big Data. It seems most of the attendees were from Bangalore and not many had come from Delhi. There were talks around infrastructure for big data systems, machine learning, data mining, etc. A few talks out of the ones we attended were really good. There were a few that we wanted to attend but couldn’t because we were busy talking to people who wanted to talk to us and know more about us. Well that’s what conferences are about - attend a few good talks and meet a lot of people. Fortunately, HasGeek will put out the recorded videos of those sessions soon. Some talks were around interesting topics and some not so much. Shailesh’s talk on The Art of Data Mining was certainly the best talk out of all the talks that I managed to attend (personal opinion).

There were poster sessions for talks that the editorial panel found interesting but not interesting enough to select them for sessions. My proposal for Using Elasticsearch for Analytics (presentation slides) was selected for a poster session, which I presented on the 2nd day of the conference. It was interesting to see that multiple teams within Flipkart, Red Hat, a couple of other product startups and services companies were interested in doing the same. So we ended up having long discussions about how are using Elasticsearch for analytics it at Wingify and how they can use Elasticsearch to solve similar problems.

Our presence at the conference

We had a desk/booth which we managed to prepare nicely to catch everyone’s attention. We got a display next to our desk on which we played our super cool video that we put on (a few people expressed that they really liked the video). I think that caught a lot of people’s attention. We also strategically placed our standees at places where it was clearly visible. Looking at other standees, I think ours was one of the best in design if not the best. We distributed our t-shirts and stickers, which seemed to attract a lot of people (more than once for the free t-shirt). A few people gave us compliments for the A-4 insert we distributed to all the participants at the time of registration. Thanks to Paras for helping out with the content and the design.

On the first day, an overwhelming number of people walked up to our booth. They were mostly unaware of our and our product’s existence. Many were blown away by the idea. Some not so much. But after talking to so many people, we figured that we were not absolutely correct about ignoring this conference as a place to promote the product and get prospective clients. Other than engineers, there were decision makers from large companies like Amazon, Citibank, Ebay and Lenovo who Ankit got a chance to speak with.

We were primarily at Fifth Elephant for the purpose of establishing the Wingify engineering brand and hiring. We were able to spread the word about what we do and got people interested about product and work. So on the front of establishing our engineering brand, we were somewhat successful - this was evident from the kind of conversations we had with people at our booth and the number of people who shared their contact details with us (this is not always very conclusive as free goodies attract people and the number can be deceiving). A lot of people were interested in understanding what kind of roles we are hiring for. These people were interested in data science and software engineering. Fingers crossed - we might get some applications soon and opportunity to work with some amazing people. People found our product cool - many did not know that something of this sort existed. I think this was one of the things that got them interested. However, some were sad to know that we are based out of Delhi instead of Bangalore, as I initially said that it seemed like most of the attendees were from Bangalore. That just says that the community in Delhi needs to work together to make Delhi more exciting for engineers.


We engaged with the community through our booth and at other moments like lunch during the conference. We got the opportunity to make connections with different startups and individuals like Jabong, BloomReach, SupportBee, Inmobi, Flipkart, GlusterFS (and Red Hat), Qubole, Myntra, Aerospike and Slideshare. I might have missed some unintentionally. We got to learn about what they are doing and we shared what we are doing. Discussions were usually about the product, engineering, our tech stack, specific engineering problems, the team, work culture, community in Delhi, etc. People were exited to know our stack and what we are doing with it. We always knew that our tech stack is not the conventional stack but we realized that it’s uncommon and cool.

In the process, we had good some good discussions and connected with good people who we think will hopefully help us with solving some problems we are trying to solve - making friends of Wingify :)

We learned about new things

We have not always been very focussed at doing a lot with collected data. With our latest release, we have come up with a number of features that make use of large amount of data our systems collect and our solutions to these problems were rather unconventional. With the latest release and our plans, we will be making more and more use of collected data for deriving useful insights for our customers and building new features that will help our customers optimize and increase their conversions. Since we have plans to work with data, The Fifth Elephant was an important conference for us to learn about what exactly is going on in the Big Data universe and how we can make use of all that at Wingify. Aerospike NoSQL Database, Cachebox, Imobi’s Grill project are just a few things that we got introduced to and we may explore them in the future for our varied use-cases. It was interesting to see people are trying to leverage SSDs for solving different kind of problems. Aerospike is a NoSQL database optimized for SSD disks and claims to be extremely performant (200,000 QPS per node). CacheBox is an advanced caching solution that leverages flash storage for improving performance for databases.

Other than these systems, there were some learning around building big data infrastructure, real-time data pipelines and data mining. There was a talk on Lessons from Elasticsearch in Production by Swaroop CH from Helpshift. We have been using Elasticsearch at Wingify and it was interesting to see that we were not facing similar problems as they were. We took that as a sign to be cautious and be prepared for firfighting such problems. These were around using Elasticsearch’s Snapshot and Restore API (they say it doesn’t work) and performing rolling upgrades (which is the recommended way of doing upgrades). We never had such problems but we are now aware that others have had such problems and we can be better prepared.

To sum up

It was a great experience being at this conference. It was for the first time we attended a Big Data conference. This ecosystem in India seems to be big and growing and hopefully there will be better content at conferences like these in the future. Thanks to HasGeek for taking the initiative. We hope that the conference will continue to happen in the years to come.

If you were present at the conference and met us there, please do not hesitate to connect with us. If you have any questions to ask regarding our experiences, go ahead and leave comments and we will get back to you. If you like what we do at Wingify and want to join the force, we will be happy to work with you. We are hiring!

Photo Credits

The beautiful photopgraphs in this post have been provided by HasGeek. You can find more photographs of The Fifth Elephant at the following links: