Research and practice in web development.
I’m Juho Vepsäläinen, a web developer and researcher. In recent years, my focus has been on web rendering, performance, and the role of AI in development and education. My research builds on years of writing books, contributing to open source, and teaching developers.
Architecture · 2026
What changes when HTML becomes the starting point for an application? This paper examines implications for codebase complexity, maintenance, and performance, while identifying questions that still need investigation.
Energy consumption · 2026
A study of 100 websites examines how caching, cookie choices, scrolling, and data volume affect energy use. The results suggest that page weight alone does not adequately explain front-end energy consumption.
AI in development · 2026
Interviews and a survey explore how developers use AI. The study reports gains in efficiency alongside concerns about code quality, security, and the need to validate generated output.
Doctoral dissertation · 2025
My dissertation examines hybrid rendering models and edge computing, and their implications for web performance and developer experience. I also advise MSc and BSc theses at Aalto University.
I bring research and development experience to architecture reviews, performance questions, and technical investigations. I also share ideas through open source projects, talks, and hands-on teaching.
SurviveJS began with books and interviews about JavaScript. That material remains available, but parts of the books are outdated as my focus has shifted toward research. Each book’s overview explains its scope and limitations.