I write
16 posts / since 2020
I'm Tejas Kumar, and I write about AI engineering, React, and the working life of a software engineer. I'm an AI Engineer at IBM based in Berlin, the author of Fluent React (O'Reilly), and the host of the ConTejas Code podcast. The archive goes back to 2020 and includes a hands on benchmark of frontier models for summarising a conversation, a long piece on how severe hemophilia A shaped my health and my work in developer relations, and a practical model for growing professional relationships.
Elsewhere on this site: Fluent React, the book on how React works inside, every talk I have given, the ConTejas Code podcast, and the workshops I teach for engineering teams.
What Is Good Taste in Software? How to Develop It
Good taste in software is a trainable skill: judging quality against external standards. 6 practice protocols, with the research under each one.
How Long Should a Keynote Speaker Speak?
A keynote runs 20 to 45 minutes, most often 30. What the attention research really says, what conferences schedule, and how to use the slot you get.
What Is an Agent Harness? Harness Engineering Explained
An agent harness is everything around an AI model that grounds it in reality: tools, context, guardrails, the loop and verification. How to build one.
Frontier Models Suck Sometimes (A Benchmark)
Apple Intelligence refused my voice note, so I benchmarked 11 AI models on it. A cheap one beat the frontier and my phone's Qwen made things up.
Biggest Lessons of 2024: Honor, Trauma, and People
Dissecting honor, what it takes to overcome trauma, how to heal from the fear of failure and prioritize relationships.
It's Okay to Code on Nights and Weekends
I love coding on nights and weekends because it's my favorite hobby. It only becomes a problem when it turns into a god or an expectation.
How to Grow Professional Relationships
My TJS model maps professional relationships across seven states, from zero-sum competition to toxic enmeshment, and why collaboration is the peak.
Health, Fitness, DevRel, and Hemophilia
A deeply personal post about my health journey and how it's affected my fitness, devrel work, and more.
Pillars of Impact for Web Engineers
I break down the four pillars of impact for web engineers: emotional, social, creative, and technical, and how to grow each one over time.
Goodbye Facebook
Why I'm deleting Facebook, Instagram, and WhatsApp: FOMO, lost time, and engagement algorithms that radicalize people. I'm moving to Signal instead.
2020 in Review: Still Thankful
A month-by-month look back at my 2020: the friends, family, and small moments that made a pandemic year worth being thankful for.
Why I Don't Prefer Speaking at Remote Conferences
Why I'd rather not speak at virtual conferences during COVID-19: the hallway conversations are the point, and video calls lose that connection.
Why I Think Remote Work is Incredible
Two months into my first fully remote job, I compare it with office life: deeper focus, better health, and the sleep rhythm trap I had to fix.
5 things I love about my website (and how they're built)
I walk through five things I love about my website, including automatic dark mode, Next.js server rendering, whimsy, and GitHub as my backend.
What I Learned From Getting Pushed Off My Bicycle
A blog post about things I learned after being randomly attacked on the streets of Berlin when a stranger pushed me off my bicycle.
Hello World
My first post here: a quick hello world I published to make sure the blog works. The real writing starts after this one.