I Will Tell You More in 10 Minutes Than Most Can in 2 Hours.
17 years of web performance means I have seen your exact problem before. Book a focused session. Get it solved. Get back to building.
Book 2 Hour Session · €300 Book 4 Hour Session · €600 Book Full Day · €1,200How It WorksThe teams I work with.
Three Steps. One Problem. Solved.
This is not a vague "pick my brain" call. I prepare before we talk, I diagnose fast, and you leave with a fix. Not a report. Not a list of suggestions. A fix.
1. You Book. I Prepare.
When you book a session, you send me your URL and a short description of the problem. Before we meet, I review your Core Web Vitals data, your waterfall, and your rendering behavior. When we start the call, I am not starting from zero. I already know where to look. That is part of the service. That is why I am fast.
2. We Diagnose. Together.
Your developer shares their screen. I walk them through Chrome DevTools, performance traces, LoAF attribution data, and the exact code paths causing the issue. I explain what is happening, why it is happening, and what we need to change. Your team understands the problem, not just the solution.
3. We Fix It. You Ship It.
If the fix is straightforward, we implement it live during the session. If it requires deeper work, you leave with the exact code changes needed and a clear plan your team can execute this sprint. Either way, the problem is solved before you hang up.
problem before. Let me show you where it is.
Currently booking sessions within 48 hours.
Client Success
Don't just take my word for it
Lead Performance Engineer, Subito
"Our search results page had been failing CLS for months. Three different developers looked at it. Arjen opened a performance trace, identified two competing layout recalculations in our listing grid, and walked us through the fix live on the call. Two hours, done."
Engineering Manager, Speak
"We booked a 4 hour block expecting it to take the full day. He diagnosed our LCP bottleneck in the first session and spent the remaining time teaching our team how to use LoAF traces. Our engineers now catch regressions themselves before they reach production."
Senior Frontend Developer, NRC
"We had an INP regression after a deploy that we could not trace. Arjen found the root cause in the first 20 minutes. A single event listener on the document body was re-rendering the entire ad stack on every scroll. Our developers shipped the fix that same afternoon."
Sound Familiar?
Every session starts with a specific problem. Here are the ones I solve most often.
The Ticket That Won't Close
Your team has a "Fix LCP" or "Improve INP" ticket that keeps moving from sprint to sprint. Nobody knows where to start. I open the performance profiler, find the bottleneck in 15 minutes, and walk your developer through the exact fix.
The Launch That Can't Wait
You are about to go live and a Core Web Vitals metric is failing. The deadline is real. I find the fastest path to a passing score and we fix it together before you ship. No panic. Just precision.
The Second Opinion
Agencies often propose €50K frontend rewrites to fix performance. Before you commit, spend €300 to find out if they are right. I will tell you what can be surgically optimized in your current stack, saving you months of unnecessary development.
A question I hear often.
"Why can't our own developers fix this?"
They can build features. Performance debugging is a different discipline. I do this 8 hours a day, 5 days a week, and have for 17 years. The patterns I recognize in 15 minutes would cost your team 3 sprints of trial and error. That is not a criticism of your engineers. It is the difference between a generalist and a specialist.
€150 per hour. No surprises.
I quote a fixed number of hours before we start. You never face open-ended billing. Most problems are solved in a single session.
Focused Session: 2 hours (€300)
One specific issue. Diagnosis, fix, and validation. This is the most common session. It handles the majority of isolated performance problems.
Deep Session: 4 hours (€600)
Multiple related issues or a complex single problem. Enough time to diagnose, implement, validate, and train your team on what changed and why.
Half Day: 8 hours (€1,200)
A comprehensive review of your entire performance stack. Can be split across multiple sessions to fit your sprint cycle. Ideal as a health check before a major release.
Not sure which one you need? Start with 2 hours. I am fast. If we uncover more, we simply extend. You only pay for the time we actually use.
No Commitment
Pay per session. No contracts, no retainers, no minimum engagement.
Fixed Quote
I tell you the number of hours before we start. If I underestimate, I finish at my own expense.
Flexible Scheduling
Split longer blocks across multiple days. Fit the sessions into your sprint.
60 Minutes. Measurable Impact.
Who What Wear is a high traffic media publisher with a complex ad stack. In a single focused session, I identified the exact layout instability sources and LCP bottlenecks their team had been chasing for months.
Their developers implemented the fixes the same week. Core Web Vitals moved from red to green. No multi-week engagement. No PDF report. One session.
This is what a 2 hour block with 17 years of experience looks like.
What 2 Hours Changed
"We booked a 4 hour block expecting it to take the full day. He diagnosed our LCP bottleneck in the first session and spent the remaining time teaching our team how to use LoAF traces. Our engineers now catch regressions themselves before they reach production."
Need Something Bigger?
Some problems run deeper than a session can solve. A JavaScript framework that blocks the main thread. A third party ecosystem with 40+ scripts. A platform with hundreds of thousands of pages that needs a complete performance overhaul.
If we uncover something like that during our session, I will tell you. I will explain exactly what the full scope looks like and what it would take to fix it permanently.
Many of my largest full consultancy clients started with a single on-call session. They booked 2 hours to solve one problem, saw how I work, and came back for the full engagement.
Full consultancy starts at €15,000 for a defined sprint. I embed with your team for 2 to 6 weeks. Deep analysis, hands-on engineering, CoreDash deployment, knowledge transfer, regression prevention. Fixed scope, fixed timeline.
On-Call
€150/hr. Solve a specific problem. See how I work.
Full Consultancy
Starting at €15,000. I embed with your team and transform the platform.
Book Your Session
Send me your URL and a short description of the problem. I will review your site before our call so we can start fixing from minute one.
Book 2 Hour Session · €300 Book 4 Hour Session · €600 Book Full Day · €1,200Not sure which session? Book a free 20 min call
Currently booking sessions within 48 hours. No commitment required.
Frequently Asked Questions
Everything you need to know before booking a session.
The Session
Is this just an audit or do you actually fix things?
I fix things. I guide your developers through the exact code changes needed, or I write the code examples myself. You leave the session with a verified solution, not a PDF.
Can my whole team join the call?
Absolutely. The more developers on the call, the better. I explain every diagnosis and every fix as we go. Your team learns while the problem gets solved. Invite everyone who works on frontend performance.
Can I record the session?
Yes. You are welcome to record the session for internal use. Many teams share the recording with developers who could not attend.
Pricing and Billing
Can I split a block across multiple sessions?
Yes. A 4 or 8 hour block can be spread across multiple days. Use the first session to diagnose and implement. Use a follow-up to validate the impact and refine. You control how the time is used.
What if the issue takes longer than the booked time?
I assess feasibility at the start of every session. If the issue exceeds the booked time, I tell you before we proceed. Once I commit to a resolution within the agreed hours, I own that estimate. If I underestimate, I finish the work at my own expense.
Technical
What technology stacks do you support?
Anything that runs in a browser. The rendering engine works the same way regardless of whether you use React, Angular, Vue, Next.js, Nuxt, Magento, Shopify, WordPress, or vanilla HTML. I debug runtime performance: JavaScript execution, layout thrashing, resource loading, main thread contention. If it renders in Chrome, I can optimize it.
Do I need to give you access to our codebase?
No. We work via screen sharing. Your developer drives, I navigate. This avoids security and compliance overhead completely. We can debug your production or staging environment directly without any access provisioning.
Which video call tool do you use?
I send a Google Meet link with the confirmation. If you prefer Zoom, Teams, or another tool, reply to the confirmation email with your invite link.