Jorrik Klijnsma
Senior Front-end Engineer @ Sopra Steria | AI Enthusiast
Veenendaal, The Netherlands
Actions
Creative developer Jorrik bridges the gap between design and functionality. With 8+ years in front-end, he's now exploring AI's potential. At Sopra Steria, he builds innovative web solutions and shares his tech journey through public speaking.
Area of Expertise
Topics
VR-First Web Development: Rethinking the Web for Immersive Browsing
Dive into the cutting-edge world of VR-first web development! As VR headsets revolutionize web browsing, we'll challenge the assumption that VR websites must be 3D and spatial. Instead, we'll explore how to adapt 2D websites for immersive experiences. From eye tracking to hand gestures, we'll uncover the key considerations that set VR-first apart from traditional and mobile-first approaches.
Learn essential design principles and development techniques to create VR-friendly websites. We'll discuss optimizing page flow, rethinking navigation, and adapting existing sites for VR. Plus, get exclusive insights from hands-on testing with Apple Vision Pro! Whether you're a seasoned dev or VR newbie, you'll leave equipped to build the future of web experiences.
This talk is designed to be both informative and interactive. I plan to include:
- Live demonstrations of VR web browsing challenges and solutions
- Before-and-after examples of websites optimized for VR
- A brief Q&A session to address audience queries and foster discussion
The content is adaptable and can be tailored to fit various time slots between 25-45 minutes. I'm happy to adjust the depth of technical details based on the expected audience expertise.
I've been actively developing and testing VR web applications for the past year, including hands-on experience with the latest VR devices. This talk synthesizes lessons learned from real-world projects and cutting-edge research in the field.
While the talk doesn't require any special equipment, I can bring a VR headset for demonstration purposes if the venue setup allows for it.
Lastly, I'm passionate about making web technologies accessible to all users, including those with disabilities. This talk will touch on important accessibility considerations for VR web experiences.
AI-Driven Code Refactoring: Improving Legacy Codebases Automatically
Ready to give your old code a makeover? Step into the world of AI-powered code refactoring, where smart algorithms take on the challenge of sprucing up cluttered codebases. See how AI deciphers code DNA, performs digital reconstructive surgery, and scales from small scripts to sprawling systems. Explore real-world success stories, understand the current limits, and discover tools that'll make your development process smoother than a freshly refactored function.
This talk will include live demonstrations of AI-driven refactoring tools in action, giving attendees a hands-on understanding of the technology. I plan to provide a balanced view, discussing both the potential and limitations of AI in code refactoring.
The content is adaptable to various skill levels, from junior developers curious about AI in coding to seasoned professionals looking to optimize their workflows. I'm happy to adjust the technical depth based on the expected audience.
To enhance engagement, I'm preparing a GitHub repository with code samples and resources that attendees can access during and after the talk. This will allow for continued learning and experimentation beyond the conference.
Lastly, I'm open to participating in panel discussions or Q&A sessions related to AI in software development if the conference schedule allows.
Prompt Injection Attacks: Understanding and Mitigating Risks in LLM-Powered Web Apps
Dive into the wild world of prompt injection attacks in LLM-powered web apps! As AI chatbots and assistants become ubiquitous, a new breed of security vulnerabilities emerges. In this hands-on adventure, we'll dissect vulnerable chatbots, craft sneaky exploits, and explore robust defense strategies.
Get ready to break (and fix) things as we create a simple LLM-powered app, then systematically exploit its weaknesses. You'll learn to identify common vulnerabilities, understand the anatomy of prompt injection attacks, and implement effective countermeasures. Perfect for devs who want to build safer AI-driven interfaces and stay ahead in the AI security game!
This talk is designed to be adaptable to different time slots (30-50 minutes) and audience levels. I can adjust the depth of technical content and number of live demonstrations based on the conference schedule and attendee profile.
I plan to provide a GitHub repository with code samples and resources for attendees to reference after the talk. This will include examples of vulnerable chatbots and secure implementations, allowing developers to continue learning and experimenting on their own.
The presentation will include interactive elements where audience members can participate in identifying vulnerabilities and suggesting mitigation strategies. This approach helps reinforce learning and keeps engagement high throughout the session.
While the talk focuses on front-end development, the principles discussed are relevant to anyone working with LLMs in web applications. I'm happy to tailor the content to emphasize aspects most relevant to your conference's focus areas.
I'm open to participating in panel discussions or Q&A sessions related to AI security if that aligns with your conference format. My background in both frontend development and AI security could bring a unique perspective to such discussions.
Ctrl+Alt+VR: Create VR-First Websites for the 2D Web
Imagine a world where your favorite websites float in mid-air, responding to your gaze and hand gestures. No, this isn't science fiction – it's the future of web browsing in virtual reality. But here's the plot twist: these websites aren't 3D models or immersive environments. They're the same 2D websites we use every day, reimagined for a VR-first world.
In this eye-opening talk, Jorrik challenges the notion that VR web development means creating complex 3D spaces. Instead, they explore how traditional websites need to evolve to meet the unique demands of VR browsing. From rethinking navigation without keyboards to optimizing layouts for eye-tracking, this session dives deep into the principles of VR-first web design and development.
Attendees will gain practical insights into creating VR-friendly websites, backed by Jorrik's hands-on experience with the Apple Vision Pro. They'll learn how to build a compelling business case for VR-first development, ensuring their skills remain cutting-edge in this rapidly evolving landscape. Whether you're a seasoned developer or just starting out, this talk will equip you with the knowledge to elevate your web projects into the VR realm – no 3D modeling required.
This talk explores adapting 2D websites for VR browsing, covering practical design principles and development techniques. Using an Apple Vision Pro I will share a demo, offering insights into next-gen web experiences. The session will be interactive, with audience participation and live VR website examples. It's relevant for developers of all levels, bridging current web practices with future VR trends.
Examples of previous experience:
Code & Comedy 2024 (Utrecht): Your LLM is so fat, it doesn't even need prompting.
JSConf Colombia 2023 (Medellin): JSON Schema Validation; A dating show between backend and frontend.
Frontmania 2023 (Utrecht): JSON Schema Validation; A dating show between backend and frontend.
https://www.youtube.com/watch?v=1vW7qT9oxxw
Nerdearla 2023 (Buenos Aires): JSON Schema Validation; A dating show between backend and frontend.:
https://youtu.be/v2t1N3g64Lk
JSNation 2023 (Amsterdam): Create AR face filters with the Chrome Face Detection API:
https://youtu.be/SYZCmKSvKlw
The Art of Waiting: Fixing Loading Spinners That Suck
We've all been there, staring at a spinning wheel, wondering if the app crashed or if we should just refresh. But here's the thing: that little spinner is doing way more psychological heavy lifting than you think.
In this talk, we'll dive into the surprisingly deep world of loading states. Jorrik will show you how to build everything from basic CSS spinners to jaw-dropping skeleton screens, and why a well-crafted loading experience can make your app feel 2x faster without changing a single line of backend code.
We'll cover the psychology behind why some loading states feel endless while others fly by, explore accessibility considerations you probably haven't thought of, and build progressively complex loaders. Plus, Jorrik will share some battle-tested patterns for handling everything from API calls to streaming responses, because in 2025, your users expect more than just a spinning circle.
By the end, you'll have a toolkit of techniques that'll make your loading states actually enjoyable to watch. Yes, really.
This talk combines practical front-end development with UX psychology in a way that's immediately applicable to any developer's daily work. I'll be sharing several different live loading implementations, from CSS-only solutions to more advanced techniques using modern web APIs.
The talk includes interactive elements where I'll demonstrate how different loading patterns affect user perception using the same underlying timing, it's quite eye-opening when you see it in action.
I've structured it to be valuable for both junior developers (who'll learn solid implementation techniques) and senior developers (who'll appreciate the performance optimization strategies and accessibility considerations). The psychology aspects make it engaging for designers and product people too.
Demo requirements: Just need to plug in my laptop and show code/browser. No special setup required.
Building Karaoke in the Browser: Web APIs That Actually Rock
What if you could build a fully functional karaoke app using nothing but modern web technologies? No native apps, no desktop software, just HTML, CSS, and JavaScript.
In this talk, Jorrik will show you how to create a karaoke experience from scratch using Web Audio API, Canvas, and a bunch of other web APIs you probably haven't played with yet. We'll tackle the fun stuff: syncing lyrics to audio, creating that bouncing ball effect, building visualizations, and making it all perform smoothly at 60fps.
But here's the twist, while we're building something fun, we're actually learning techniques that'll make you a better developer in your day job. The timing precision needed for karaoke? That's the same stuff you need for smooth animations or data hadnling in enterprise apps. The audio processing? Perfect for building better video conferencing tools.
Jorrik will take you through the core features, show you how to handle the tricky bits (audio sync is harder than it looks), and share some battle-tested patterns for high-performance web apps. And if the conference is up for it, we might just end the day with an actual karaoke party using the app we built.
This is a hands-on technical talk that uses a fun, engaging project to teach serious web development concepts. I'll be showing a working karaoke app during the presentation, demonstrating Web Audio API, Canvas animations, performance optimization, and modern JavaScript patterns.
The karaoke theme makes complex topics like audio processing and real-time synchronization more accessible and memorable. Attendees will leave with practical knowledge about browser APIs they can apply to media apps, dashboards, games, data processing, and other interactive experiences.
Optional add-on: If you're interested, I'd love to host a karaoke session using the app at an after-party or end-of-day event. It's a great way to let people actually experience what has been shared on stage and creates a memorable conference moment. (This is totally optional and the talk stands on its own!)
Demo requirements: Audio output capability, microphone access preferred but not required. I'll bring backup audio files and handle any technical setup.
Prompt Engineering for Developers: Build Tools That Actually Work
Let's be honest, most developers are still treating AI like a fancy search engine. Copy-paste some code, ask it to debug something, maybe generate a quick function. But what if with using the right prompting techniques, you could build custom AI tools that actually solve your daily development problems?
In this hands-on workshop, we'll go way beyond "write me a React component." You'll learn how to engineer prompts that consistently produce the results you need, build simple but powerful AI-powered tools for your workflow, and create multi-step processes that handle complex development tasks.
We'll cover role-specific prompting for different types of development work, techniques for building context that leads to better code generation, and strategies for chaining prompts together to tackle bigger challenges. Plus, we'll dive into the practical stuff, how to validate AI-generated code, handle edge cases, and avoid the common pitfalls that make AI tools unreliable.
By the end, you'll have a toolkit of techniques and actual working tools you can use immediately. No more fighting with ChatGPT/Claude/Gemini to give you what you want, you'll know exactly how to ask for it.
This workshop takes a practical, developer-focused approach to prompt engineering. Participants will work through real coding scenarios and build actual tools they can use in their development workflow.
The workshop is structured around hands-on exercises where developers create:
- Custom code review prompts tailored to their tech stack
- AI-powered debugging assistants
- Documentation generators that understand their codebase
- Multi-step workflows for complex development tasks
I've designed it to be immediately applicable, everyone leaves with working tools and techniques they can implement the next day. The focus is on engineering reliable, repeatable results rather than just getting lucky with prompts.
Workshop requirements: Participants should bring laptops and have access to an AI tool (ChatGPT, Claude, Gemini, etc.). No special software installation required.
NDC Melbourne 2025 Sessionize Event
Prompt Engineering Bulgaria 2024 Sessionize Event
Prompt Engineering Conference 2024 Sessionize Event
DevFest London 2024 Sessionize Event
DevFest Bari 2024 Sessionize Event
Full-Stack Summer Sessions
There will be a variety of subjects, such as Monadic-style coding, Intro to NX, and others. We have four confirmed speakers during two-time slots. There will be food and drinks in between the two sessions. More information will be shared as soon as possible.
Front-end Festival
On the 5th of September, Sopra Steria will be hosting the second iteration of the Frontend Festival! Join us for an evening of drinks, talks, and workshops about various topics in the world of opensource Frontend development.
Azure AI Summer Jam Sessionize Event
JSConf Colombia 2023 - 10th anniversary and Final edition Sessionize Event
Frontmania 2023 Sessionize Event
Nerdearla 2023 Sessionize Event
J-Fall 2022 Sessionize Event
Frontmania 2022 Sessionize Event
Jorrik Klijnsma
Senior Front-end Engineer @ Sopra Steria | AI Enthusiast
Veenendaal, The Netherlands
Actions
Please note that Sessionize is not responsible for the accuracy or validity of the data provided by speakers. If you suspect this profile to be fake or spam, please let us know.
Jump to top