Tejas Kumar

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80 talks / 64 events / 2012 to 2026

I have been on a stage since 2012 and at conferences since 2018. Here is what I speak about, where I have spoken, and how to get me to your event.

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80 talks at 64 events, 2012 to 2026. Here they all are.

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What do I speak about?

I'm Tejas Kumar, a conference speaker and an AI Engineer at IBM, based in Berlin, Germany. I have given 80 recorded talks at 64 events between 2012 and 2026, including React Summit, React Advanced London, React Day Berlin, JSConf EU, CityJS London, GOTO, CascadiaJS, RenderATL, AI Engineer Europe and TEDxYouth@Doha. I speak about AI engineering, React internals and Server Components, developer health, and the JavaScript platform, and I write live code on stage. I am also the best selling author of Fluent React, published by O'Reilly, and the host of the ConTejas Code podcast, so a talk comes with a book and a weekly podcast archive of the same material behind it. Booking enquiries go by email.

AI engineering

Large language models, retrieval, agents, the Model Context Protocol, and what it actually takes to ship them. This is most of what I have spoken about since 2024.

React

Server Components, Suspense, concurrent rendering, streaming, and the tradeoffs React makes underneath. The same material as Fluent React, compressed into a conference slot.

JavaScript and the web platform

WebAssembly, data at scale, infrastructure, design systems, and the older parts of the stack that still decide how fast a page feels.

Developer health

What building software does to a body. I have severe hemophilia A and have been building on the web for over 25 years.

Documentation and developer experience

Writing docs people finish, and treating developer experience as an engineering problem rather than a marketing one.

Do I give inspirational or non technical keynotes?

Yes. Alongside the technical talks there is a keynote of my own story, and it needs no technical audience at all. I was born with severe hemophilia A, a blood disorder that killed me once before I was 5. I got about 19 days of school a year, taught myself to build the web on the family computer in our dining room, and used that to leave a country where my medicine cost more than most people there earn. It exists as a full length keynote and as a 20 minute version, and the whole account is on my story page.

Read the whole thing: 1992 to today, in chapters, written by me.

Do I preach at churches and Christian conferences?

Yes. I became a Christian at 15, and I have served in my church as a youth leader, a worship leader, a men's ministry leader, a deacon and in care ministry. In a church the work is preaching, not a talk about myself: a sermon out of the Bible, with the things I have lived through as the illustration rather than as the subject. That includes the healing at 19 that I still cannot account for, which is a better argument for the text than it is a story about me. A Sunday service, a church conference, a camp and a youth event are all the same work. The account of what I have lived through is on my story page.

Read the account, or write to me about a service or a conference.

Where have I spoken?

I have given 80 recorded talks at 64 events between 2012 and 2026. Those events include React Summit, React Advanced London, React Day Berlin, React Paris, React Miami, React India, React Norway, RenderATL, JSConf EU, JSConf Budapest, JSConf Armenia, JSNation, CityJS London, CascadiaJS, DinosaurJS, GOTO, Build Stuff, Next.js Conf, SmashingConf New York, Infobip Shift, WebCamp Zagreb, How to Web, Frontend Nation, Future Frontend, AI Engineer Europe and TEDxYouth@Doha. Three of the 64 are meetups and one is a podcast, so 64 events is the accurate number rather than 64 conferences.

The full archive is at the bottom of this page. My calendar has the dates: every event I'm booked at, where it is, and which days are still open.

What is one of my talks like?

A talk of mine is usually built around live code: I write it on stage rather than showing a finished screenshot of it. I have given lightning talks, conference talks, meetup talks, a TEDx talk, and live streamed sessions. Here is what other speakers have said about it.

  • Josh W. Comeau
    Josh W. Comeau@JoshWComeau

    I’ve said it before, but @tejaskumar_ has the most amazing energy when he speaks (and also in real life!). Amazing talk as usual about the tradeoffs React makes and why they’re really pretty good compromises.

    Jun 1, 2023View on
  • Mark Dalgleish
    Mark Dalgleish@markdalgleish

    .@tejaskumar_ is such a charismatic speaker.

    Oct 20, 2023View on
  • David K 🎹
    David K 🎹@davidkpiano

    Whenever @tejaskumar_ live codes in a presentation, it's absolutely stunning. Feels like he can turn almost anything into a 2-minute demo.

    May 7, 2022View on
  • Cassidy
    Cassidy@cassidoo

    This talk by @tejaskumar_ is so inspiring. He’s got hemophilia, and he built an app that has a data visualization of the half life of his medicine! #DinoJS

    Jun 20, 2019View on
  • Francesco
    Francesco@FrancescoCiull4

    I met Tejas Kumar !!!!

    An amazing speaker and a super friendly, funny person in real life!

    Thanks for wearing my sticker @tejaskumar_!!

    Nov 20, 2022View on
  • swyx
    swyx@swyx

    dude. i wish i had your energy, technical, and speaking skills! I dont know how you do it.

    Sep 26, 2019View on

What formats do I speak in?

I give conference keynotes and conference talks, lightning talks, meetup talks, live streamed sessions, and podcast interviews. The archive below covers all five, from a TEDx talk in 2012 to conference talks in 2026.

  • Conference keynotes and conference talksMost of the archive: React Summit, JSConf EU, GOTO, Build Stuff, CascadiaJS, RenderATL and the rest.
  • Lightning talksShort slots at dotJS and JSConf EU.
  • Meetup talksReact Berlin, TypeScript Berlin and React Universe Berlin.
  • Live streamed sessionsCityJS London and Serverless in the Park were streamed live.
  • Podcast interviewsRecorded conversations, such as the LogRocket podcast.

What language do I speak in?

I speak and present in English. My talks, my book Fluent React, and every episode of the ConTejas Code podcast are in English, and I am based in Berlin, Germany.

How do you book me to speak?

Email is the fastest way. I'm based in Berlin, Germany, and I travel for events. Include the date, the city, the audience size, the topic you want, and how long the slot is, and you will get a straight yes or no.

Send a speaking enquiryOr reach me on LinkedIn

Speaker bio, ready to paste

Tejas Kumar is an AI Engineer at IBM, based in Berlin, Germany. He is the best selling author of Fluent React (O'Reilly) and the host of the ConTejas Code podcast. He has been building on the web for over 25 years and has given 80 recorded talks at 64 events since 2012.

One line version

Tejas Kumar, AI Engineer at IBM, best selling author of Fluent React (O'Reilly), host of ConTejas Code.

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Every recorded talk, 2012 to 2026

80 talks / 64 events

Titles and years come from the recordings themselves. Where only an event name is known, that is what is printed, because a title nobody can check is worse than no title. Every row here opens the recording on YouTube, and 23 of them also have the full transcript on this site, so what was said can be read.

Elsewhere

There is Fluent React, the O'Reilly book on how React works inside, ConTejas Code, the podcast, and more about me. If you are organizing a remote event, read why I do not prefer speaking at remote conferences first.