Growing Your Brand Beyond Technical Fixes | Sia Karamalegos | ThemeVitals | Bonus Episode
On this bonus episode of Honest Ecommerce, we have Sia Karamalegos. She is a freelance developer and web performance engineer, a Google Developer Expert in web technologies, and formerly worked on the Shopify performance team. We talk about the difference between Lighthouse and Core Web Vitals, why site performance matters for bounce and conversion rates—not just SEO, how ThemeVitals collects and uses real-world data to benchmark Shopify themes, and how both merchants and theme developers can use it to make better performance decisions and so much more!
Honest Ecommerce · Chase Clymer with Sia Karamalegos
Audio is streamed directly from the publisher (prfx.byspotify.com) as published in their RSS feed. Play Podcasts does not host this file. Rights-holders can request removal through the copyright & takedown page.
Show Notes
Sia Karamalegos is a freelance web developer and web performance engineer helping ecommerce brands turn faster load times into real revenue. As a Google Developer Expert in Web Technologies and a former engineer on Shopify’s performance team, Sia brings a unique blend of hands-on experience and deep technical insight to the challenge of building faster, more performant online stores.
With a passion for developer education and community building, Sia organizes the Eleventy Meetup, Durham Social Hack Night, and a new global web performance meetup, connecting engineers around the world to share real-world tactics and tools. She’s also a frequent international speaker and writer, known for making complex topics like Core Web Vitals and JavaScript performance approachable and actionable.
In 2024, Sia launched ThemeVitals, a tool that benchmarks Shopify themes using real user data—not lab simulations to uncover which themes actually perform well across the devices your customers use. It’s a mission rooted in impact: helping merchants and theme developers make smarter, faster decisions that drive conversion and long-term growth.
Through her work, Sia is redefining how ecommerce teams think about performance, showing that real user data, smart defaults, and community-driven tooling can transform the way we build the web.
In This Conversation We Discuss:
- [00:40] Intro
- [01:00] Focusing on real-world site speed fixes
- [02:39] Improving performance metrics for merchants
- [04:22] Translating Google metrics for merchants
- [04:56] Understanding how Core Web Vitals work
- [07:34] Balancing traffic vs technical optimization
- [10:36] Shifting focus from speed to sales
- [13:16] Balancing performance with product experience
- [15:26] Highlighting global device performance gaps
- [16:54] Uploading giant images the wrong way
- [21:04] Auditing your tech stack regularly
- [21:53] Comparing Shopify themes with real data
- [24:11] Balancing features vs speed in theme choice
- [26:00] Avoiding minimalist themes that lack function
- [28:08] Encouraging feedback for future improvements
Resources:
- Subscribe to Honest Ecommerce on Youtube
- Explore real-world Core Web Vitals performance data for popular Shopify themes themevitals.com/
- Web Developer & Performance Engineer sia.codes/
- Follow Sia Karamalegos linkedin.com/in/karamalegos
If you’re enjoying the show, we’d love it if you left Honest Ecommerce a review on Apple Podcasts. It makes a huge impact on the success of the podcast, and we love reading every one of your reviews!