Your Codebase. Your Data. Your Team.
I train engineering teams and agencies to find and fix Core Web Vitals issues independently. Not generic slides. Not prerecorded video. Live sessions on your actual production site, using your real performance data.
Book for Your TeamSee the TracksThe teams I train.
Choose Your Path
Both tracks share the same technical foundation. The difference is what your team does with it afterward.
Engineering Team Training
Your developers learn to diagnose and fix Core Web Vitals on your own platform. After the training, your team handles performance independently. No ongoing dependency on me.
Agency Training
Your team learns to deliver Core Web Vitals audits and optimizations for your clients. Turn performance into a billable service instead of something you outsource.
A question that comes up every time.
"We watched the YouTube videos. We read the web.dev docs. Why are our scores still red?"
Because generic advice does not transfer to your specific architecture. Your third party stack, your framework hydration, your ad setup, your image pipeline. These are unique to you. A video cannot open Chrome DevTools on your production site and show your developers exactly where the 400ms of input delay is coming from. I can.
What Every Session Covers
The core curriculum is shared across both tracks. Agency training adds modules on client delivery, reporting, and selling performance services.
Browser Internals
How the browser parses HTML, builds the DOM, calculates styles, lays out elements, and paints pixels. You understand the machine to master the metrics. This is the foundation everything else builds on.
Advanced Core Web Vitals
Beyond definitions. LCP subparts, INP phases (input delay, processing, presentation delay), CLS session windows. You learn to read CrUX data, compare it against lab results, and understand why they disagree.Real cases from real sites, including client work featured on web.dev.
Performance Profiler Mastery
Chrome DevTools is the most powerful diagnostic tool you have. You learn to read flame charts, trace long tasks, identify LoAF attribution data, and connect what you see in the profiler to what your users experience in the field.
Architectural Strategy
Third party governance, hydration strategies, resource prioritization, performance budgets in CI/CD. You learn to maintain performance at scale and prevent regression after every deploy.
Modules Exclusive to Agency Training
Client Reporting
How to present CWV data to non-technical stakeholders. Translating metrics into business outcomes your clients actually care about.
Scoping and Pricing
How to scope a performance audit, estimate hours accurately, and price the work. What to include, what to exclude, and how to set expectations.
CoreDash for Client Monitoring
Set up Real User Monitoring for each client. Track their Core Web Vitals continuously. Use the data to identify new optimization opportunities and demonstrate ongoing value.
9 Hours. 3 Sessions. Your Real Problems.
Each session is 3 hours. We typically schedule them across 1 to 2 weeks so your team has time to absorb the material and try things between sessions.
Every session follows the same structure:
2 Hours: Theory and Concepts
Deep dive into browser internals, metric mechanics, and diagnostic techniques. I explain the why, not just the what.
1 Hour: Your Real Cases
We open your site in Chrome DevTools and apply what we just covered. Your current performance tickets, your actual regressions, your specific third party issues. We solve them live.
This is a hybrid between training and consultancy. Your team learns the skills while we simultaneously fix real problems on your site.
teams at eBay, Adevinta, KPN, and DPG Media.
Client Success
Don't just take my word for it
Lead Engineer, DPG Media
"Arjen simplifies the most complicated performance issues and he is really passionate about it. It makes learning the hard stuff actually enjoyable."
Senior Frontend Dev, Jamie Oliver Group
"After this training we finally understand exactly why our INP scores were failing and knew precisely which interaction costs to cut."
Engineering Lead, Loop
"It's amazing how simple Arjen can make LCP optimization sound. We applied his framework and saw our metrics improve by 40% within a single week."
Flat Rate. No Seat Limit.
I price per team, not per person. Bring your entire frontend team. Invite your QA engineers. Let your tech lead sit in. The more people in the room, the faster performance becomes part of your culture.
Make Your Team Self-Sufficient
Turn Performance Into Revenue
All prices exclude VAT. Sessions are delivered online via Google Meet. Your preferred tool (Zoom, Teams) works too.
After the Training
Your team will handle 90% of performance issues independently. For the other 10%, the complex edge cases where you need a second pair of eyes, two options exist.
On-call sessions at €150/hr. Book 2 hours when your team gets stuck on something specific. I diagnose, we fix, they ship. Most teams book one or two sessions per quarter after training.
Full consultancy starting at €15,000. If the training uncovers architectural issues that go deeper than your team can handle alone, I embed for 2 to 6 weeks and we rebuild the performance infrastructure together.
Many of my largest consultancy engagements started as a training. The team learned the fundamentals, identified the real scope of the problem, and came back with the full brief.
Training
Build the skill. Your team becomes self-sufficient.
On-Call
€150/hr. When you need expert eyes on a specific problem.
Full Consultancy
Starting at €15,000. I embed with your team and transform the platform.
Book Training for Your Team
Tell me about your team, your stack, and the performance challenges you are facing. I will tailor the curriculum to your specific situation and propose a schedule that fits your sprint cycle.
Book TrainingCurrently scheduling sessions within 2 weeks. No commitment until we agree on the scope.
Frequently Asked Questions
Common questions before booking on scope, depth, logistics, and what your team takes away.
Technical Scope
Is this training for beginners?
No. Your developers need a basic understanding of JavaScript and web development. We skip the fundamentals and go straight into browser mechanics, performance profiling, and real diagnostic work. If your team already knows how to open DevTools but not how to interpret a flame chart, this is the right level.
Do you focus on specific frameworks like React or Next.js?
I focus on the browser. The rendering engine applies the same rules regardless of whether you use React, Angular, Vue, Next.js, Nuxt, Magento, Shopify, or vanilla HTML. That said, since we work on your actual site, the training naturally covers the framework-specific patterns that affect your performance. If your hydration strategy is the bottleneck, that is what we debug together.
Do you cover INP in depth?
Yes. INP is where most teams struggle. We spend dedicated time dissecting the main thread, the event loop, input delay, processing time, and presentation delay. Your developers learn to identify long tasks, trace LoAF attribution data, and break up heavy JavaScript execution to keep interactions responsive.
Do you cover third party script management?
Yes. You cannot simply delete your marketing tags. I teach your team how to govern them: loading strategies, execution timing, yield patterns for tag managers, and how to quantify the performance cost of each script so you can make informed decisions about what stays and what goes.
Format and Logistics
Will we work on our actual website?
Yes. Every session reserves 1 hour for live debugging on your production or staging environment. We take your current performance tickets, the regressions your team has been chasing, and solve them live using the techniques we just covered. This is a hybrid between training and consultancy. Your team learns the skills while we simultaneously fix real problems.
How many people can attend?
No seat limit. Pricing is per team, not per person. Invite your entire frontend team, your QA engineers, your tech lead. The more people who attend, the faster performance becomes embedded in your workflow. For groups above 20, we may adjust the format slightly to keep the sessions interactive.
What is the schedule?
Three sessions of 3 hours each. We typically schedule these across 1 to 2 weeks so your team can absorb the material and experiment between sessions. I am flexible on timing. We find slots that work with your sprint cycle.
Do you provide a recording?
Yes. You get the full recording of every session and the slide deck. Your team can review the profiling techniques and browser mechanics at their own pace. Developers who could not attend can watch the recording and follow along.
Agency Track
What makes the agency track different?
The agency track includes everything in the engineering team training, plus three additional modules: how to present Core Web Vitals results to non-technical clients, how to scope and price performance audits, and how to set up CoreDash for ongoing client monitoring. The goal is for your agency to leave with a new billable service, not just technical knowledge.
Do we use a real client site during the training?
Yes. Pick the client site your team is most familiar with. We use it for the live debugging portions. By the end of the training, your team will have diagnosed real performance issues on a client site and have a concrete optimization roadmap to deliver.
