JSFoo 2016

Tackling speed and performance for JavaScript

##About JSFoo

JSFoo is India’s premier JavaScript conference. We launched JSFoo in 2011 as India’s first JavaScript conference. The JS community in India has grown phenomenally since. JavaScript now pervades every aspect of web development – browsers, apps, front-end, backend, mobile, and IoT.

##JSFoo 2016: Theme

Over the last few years, JavaScript has evolved to become the centerpiece of a complex web stack. Today, it is a prime subject of the obsession that lies with performance and speed. How can you get pages to load faster? How do you work with browser constraints to enhance speed? How do you measure performance? What actually is performance? In what ways do faster response times influence your architecture choices and plans? How is this new focus on faster page loads and apps working offline influencing the development of front-ends and backends as well as server side JS?

The theme for the 2016 edition is tackling speed and performance for JavaScript.

We are inviting full talks (40 mins), crisp talks (15 mins + 5 mins Q&A), and 3-6 hour long (hands-on) workshops from practitioners on the overall theme of speed and performance, including the following topics:

  • Architecting for performance – case studies on how you got faster response times
  • Best practices: debugging and profiling on the web, measuring performance
  • Handling large volumes of data in the browser
  • Building and deploying web apps eg webpack, travis
  • Modern web technology: Angular 2, React
  • Universal JavaScript: meteor js
  • Progressive Web Apps
  • JS off the web – raspberry pi, IoT
  • The cutting edge: elm

This year, JSFoo will feature two days of talks on JavaScript (15-16 September) and a single day of talks on design (17 September) at Meta Refresh (call for proposals will open shortly).

Guidelines for submission

Every proposal MUST be accompanied by:

  • A three minute preview video where the proposer gives an elevator pitch about the talk.
  • Detailed outline of the talk – either in the form of draft slides, mind map and/or textual description.
  • If you are proposing to speak on a topic where the code is not open-sourced yet, the editorial panel will consider your proposal only if the code is made open-source at least three weeks before the conference.

Without the above information, your proposal will not be considered for review.

If you are submitting a Workshop Proposal, you must clearly state:

  • Background knowledge that participants must possess in order to attend your workshop.
  • Details and links to software / packages which participants must install before coming to the workshop.
  • Laptop configuration.
  • Links to background reading material and GitHub repos.
  • Duration of the workshop.
  • Maximum number of participants who can attend your workshop.
  • Instructor’s past experience with conducting workshops.

There is only one speaker per session. Workshops can have two or more instructors.

Entry is free for selected speakers.

Due to budgetary constraints, we prefer speakers closer to home. But if we think you stand out, we’ll provide a grant to cover part of your travel and accommodation to Bangalore. Grants are limited and are made available to speakers delivering full sessions (40 minutes or longer) only.

Commitment to open source

HasGeek believes in open source as the binding force of our community. If you are describing a codebase for developers to work with, we’d like for it to be available under a permissive open source licence. If your software is commercially licensed or available under a combination of commercial and restrictive open source licences (such as the various forms of the GPL), please consider picking up a sponsorship. We recognise that there are valid reasons for commercial licensing, but ask that you support us in return for giving you an audience. Your session will be marked on the schedule as a sponsored session.

Important dates:

Deadline for submitting proposals: 29 August 2015
Conference dates: 15-16 September

JSFoo will be held at the MLR Convention Centre, J P Nagar.

For more information about speaking proposals, tickets and sponsorships, contact info@hasgeek.com or call +91-7676332020.

Hosted by

JSFoo is a forum for discussing UI engineering; fullstack development; web applications engineering, performance, security and design; accessibility; and latest developments in #JavaScript. Follow JSFoo on Twitter more

Prasenjit Sharan


Immutability and JavaScript

Submitted Aug 9, 2016

By definition, immutable means “unchanging over time”. Immutability is one of the core concepts of functional programming paradigm. It finds its roots from languages like Haskell, Clojure, and Scala. It has seen an exponential rise in popularity and adoption in JavaScript application development over the last few years.

This talk is an in-depth analysis of what exactly is immutability and how does it fit in our current JavaScript application development ecosystem. It also discusses how can immutability help in building high-performance JavaScript applications.

The key takeaways from the talk would be knowledge of immutability as a concept and how to apply it in practical use-cases.

The audience can be a group of anyone from beginner to advanced level JavaScript application developers and architects.


Immutability, as a concept, is one of the main pillars of functional programming. In this talk, along with the core concepts, we’ll see how does one use it in practice.

We’ll try to answer the following questions -

  1. What is immutability? What does it really mean for data and data structures to be immutable?
  2. What makes it important? Why should one use immutability?
  3. What are the use-cases for using immutability in an application? What are the anti-patterns?
  4. How to use immutability in JavaScript? What are the relevant libraries and patterns?
  5. How can it lead to high-performance application development? How does it fare against traditional programming approaches?

We’ll see how immutability in JavaScript works using structural sharing, robust and easy handling of persistence, locking, copying, comparison, and maintaining states of data. All this, keeping the simplicity intact.

Speaker bio

I’m a Front-end Engineer, with experience of around 6 years in front-end development. Currently, I’m working with the product team of Helpshift, Pune, on a customer support platform product for mobile apps. I am responsible for end to end architecture and development of features; performance, and optimization of the product.

I’ve had experience in functional programming from my time at Amazon, Hyderabad, and my team here at Helpshift uses Clojure at the back-end and libraries such as React and Immutable.js on front-end.


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Hosted by

JSFoo is a forum for discussing UI engineering; fullstack development; web applications engineering, performance, security and design; accessibility; and latest developments in #JavaScript. Follow JSFoo on Twitter more