Speed up your website. Shopify. WordPress. Custom apps. - Aleksandar Kuzmanovic offers many high-quality services. Is your website slow? Whether you need to speed up your Shopify store, improve your WordPress website speed, or optimise a custom web application — I deliver measurable performance improvements that directly impact your rankings and revenue. Key stats: <1s Load times, 100 Lighthouse score, 2566% Traffic growth, +200% Conversion lift. Technologies: Core Web Vitals, Lighthouse, Next.js, WordPress, Shopify, Cloudflare, Redis, AVIF/WebP, Server-Side Rendering, Edge Caching, CDN, Performance Monitoring. Contact: aleksandarkuzmanovic02@gmail.com.
Speed up your website.
Shopify. WordPress. Custom apps.
Is your website slow? Whether you need to speed up your Shopify store, improve your WordPress website speed, or optimise a custom web application — I deliver measurable performance improvements that directly impact your rankings and revenue.
I'm Aleksandar Kuzmanovic, a performance engineer and full-stack developer with 12+ years of experience. I've built Serbia's fastest eCommerce platform with sub-1-second load times and consistently deliver perfect Core Web Vitals scores. I don't just make websites faster — I engineer them for speed at every layer of the stack.
Speed impacts everything: search rankings, bounce rates, conversion rates, and user satisfaction. Google's Core Web Vitals (LCP, INP, CLS) are confirmed ranking factors. A 1-second delay in page load reduces conversions by 7%. I attack performance problems at the root — server configuration, rendering strategy, asset delivery, code efficiency, and caching architecture.
Is your website slow? Whether you need to speed up your Shopify store, improve your WordPress website speed, or optimise a custom web application — I deliver measurable performance improvements that directly impact your rankings and revenue.
Services & deliverables.
End-to-end.
Performance Audit & Report
Comprehensive speed audit with Lighthouse, WebPageTest, and Chrome DevTools. Prioritised list of issues with estimated impact, root cause analysis, and implementation plan.
Core Web Vitals Fixes
LCP, INP, and CLS optimisation — image compression, font loading, layout shift prevention, JavaScript defer, and critical CSS extraction. Every metric moves to green.
Shopify Speed Optimisation
Theme code audit, app bloat removal, image optimisation, lazy loading, script defer, and liquid template optimisation. Measurable speed improvements for your Shopify store.
WordPress Speed Optimisation
Server caching, plugin audit, database optimisation, CDN configuration, image compression, and optional headless WordPress migration for maximum performance.
Server & CDN Configuration
Server-side caching, edge caching, CDN setup, GZIP/Brotli compression, HTTP/2, and preconnect/preload directives. Infrastructure-level speed improvements.
Ongoing Speed Monitoring
Automated performance monitoring, Core Web Vitals tracking, regression alerts, and monthly performance reports. Your site stays fast after optimisation.
Why hire me for website speed optimisation?
Shopify Speed Optimisation
I audit and optimise Shopify stores — image compression, theme code cleanup, app bloat removal, lazy loading, critical CSS extraction, and third-party script management. Your store loads faster and converts better.
WordPress Speed Optimisation
Server-side caching, image optimisation, plugin audit, database cleanup, CDN configuration, and headless WordPress architectures with Next.js frontends for maximum performance.
Core Web Vitals Engineering
LCP, INP, and CLS optimisation through server-side rendering, code splitting, image next-gen formats (AVIF/WebP), font optimisation, and layout shift elimination. Every metric scores green.
Full-Stack Performance
I optimise the entire stack — frontend rendering, API response times, database queries, caching layers, and CDN configuration. Speed improvements are architectural, not superficial.
Image & Asset Optimisation
Next-gen image formats (AVIF/WebP), responsive images, lazy loading, font subsetting, CSS/JS minification, and tree shaking. Every byte matters for load time.
Server-Side Rendering & Edge Computing
Migrate client-rendered applications to server-side rendering with Next.js. Edge functions and middleware for globally distributed, low-latency responses.
My process.
Simple. Transparent.
Speed Audit
Lighthouse testing, WebPageTest waterfall analysis, Core Web Vitals assessment, and third-party script impact measurement. Identify every bottleneck with data.
Quick Wins
Image compression, lazy loading, font optimisation, and critical CSS extraction. Immediate improvements that show measurable speed gains within days.
Architectural Fixes
Server-side rendering migration, code splitting, bundle size reduction, caching strategy implementation, and CDN configuration. Structural speed improvements.
Platform-Specific Tuning
Shopify theme optimisation, WordPress plugin audit, database cleanup, or custom application profiling. Platform-specific fixes that address root-cause performance issues.
Verification & Monitoring
Before-and-after metrics comparison, Core Web Vitals field data validation, and monitoring setup for ongoing performance tracking and regression detection.
Technology Stack
Why website speed is a business metric.
Website speed is not a technical vanity metric — it is a direct driver of revenue, rankings, and user experience. Google has confirmed that Core Web Vitals (LCP, INP, CLS) are ranking factors. Research from Google shows that as page load time increases from 1s to 3s, the probability of bounce increases by 32%. From 1s to 5s, it increases by 90%.
For eCommerce, the impact is even more dramatic. Amazon famously calculated that every 100ms of additional load time cost them 1% in revenue. Walmart found that for every 1-second improvement in page load time, conversions increased by 2%. Aleksandar's own eCommerce results confirm this: sub-1-second load times contributed to a 200% conversion lift for a home goods retailer.
Core Web Vitals measure three specific aspects of user experience. LCP (Largest Contentful Paint) measures loading performance — how quickly the main content becomes visible. INP (Interaction to Next Paint) measures responsiveness — how quickly the page responds to user input. CLS (Cumulative Layout Shift) measures visual stability — whether content shifts around as the page loads. All three must pass for Google to consider your site as having a good page experience.
Most speed optimisation services focus on surface-level fixes: compressing images, enabling caching, minifying CSS. While these help, they rarely address the root causes of poor performance. Aleksandar approaches speed optimisation as a full-stack engineering problem — analysing server response times, rendering strategies, JavaScript execution, database queries, and network waterfalls to find and fix the actual bottlenecks.
The most impactful speed improvement is often architectural: migrating from client-side rendering to server-side rendering, implementing proper caching layers, or moving to a CDN-first delivery model. These changes can reduce load times by 50-80% and are impossible to achieve through plugin-based optimisation alone. Aleksandar's engineering background enables these architectural transformations that marketing-focused speed consultants cannot deliver.
Common questions.
Clear answers.
- How can I speed up my Shopify store?
- Optimise product images (WebP/AVIF), remove unused apps, minimise JS/CSS, implement lazy loading, use a lightweight theme, leverage browser caching, and optimise third-party scripts. I've built eCommerce platforms with sub-1s load times.
- How do I improve my WordPress website speed?
- Use quality hosting, implement server-side caching, optimise images, minimise plugins, use a CDN, enable GZIP, optimise the database, and consider a headless WordPress setup with Next.js for maximum speed.
- Why is website speed important for SEO?
- Google uses Core Web Vitals as ranking factors. Faster sites rank higher, get more traffic, have lower bounce rates, and convert better. A 1-second delay reduces conversions by 7%.
- What Core Web Vitals scores should my website aim for?
- LCP under 2.5s, INP under 200ms, CLS under 0.1. I consistently deliver perfect 100/100 Lighthouse scores and all-green Core Web Vitals.
- How much can website speed improve my SEO rankings?
- Core Web Vitals are confirmed Google ranking factors. Sites that move from failing to passing Core Web Vitals typically see 5-15% traffic increases from improved rankings alone, plus lower bounce rates and higher time-on-site that further boost rankings.
- Can you fix a slow website without rebuilding it?
- Yes. Aleksandar performs targeted performance audits that identify and fix specific bottlenecks — image optimisation, caching, code splitting, third-party script management, and server configuration — without requiring a full rebuild.
- What causes Cumulative Layout Shift (CLS)?
- CLS is caused by images without dimensions, dynamically injected content, web fonts causing text reflow, and ads or embeds loading after the page renders. Aleksandar fixes CLS by reserving space for dynamic elements, using font-display strategies, and implementing proper aspect ratios.
- How do you measure website speed improvements?
- Before-and-after Lighthouse audits, Core Web Vitals field data from Chrome UX Report, WebPageTest waterfalls, and Google Search Console performance data. Every improvement is measured and documented with real metrics.
Ready to start?
Send a message and I'll respond within 24 hours with a clear plan for your project.