Available for assignments

Jeroen Wever

Freelance staff-level engineer. Almost 20 years of building web products people actually use. I build products that ship.

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About

Curious, autodidactic engineer with almost 20 years of building web products people actually use, from the Benelux's biggest news and entertainment brands to real-time sports betting. I go deep where it matters most: server-side rendering at scale, analytics and experimentation that turn opinions into decisions. Everything I build is meant to stop needing me, whether that's a casino platform or an engineer. It usually ships sooner than the budget assumed.

Experience

Freelance Full Stack Developer · Nederlandse Loterij (TOTO)

Jan 2023 – present

Three engagements on TOTO's gambling platforms: a brand integration into the legacy casino, a ground-up casino rebuild, and the new TOTO Sport sportsbook. All real-time, all under strict gambling regulation, peaking at 100,000 active users a night.

  • Shipped the Winn-It brand into the legacy casino platform in six weeks, against a six-month budget
  • Rebuilt the casino from scratch on Vue 3 and .NET, then handed it over to newly hired in-house developers. The team chose a custom SSR stack over Nuxt: no vendor lock-in, and every dev learns what a meta-framework does under the hood
  • Owned the initial SSR implementation for both casino and sportsbook. Researched the hard parts (memory leaks and state leaking across requests) and coached the team on preventing both
  • Turned a three-month sportsbook proof-of-concept into a green light at the halfway demo. With four devs, reached closed beta in a year and replaced the legacy product six months later, handling peaks of 4,000 logins and 2,000 bets per minute
  • Built the custom Google Analytics enhanced-ecommerce funnel for betting, plus the sportsbook's custom A/B-testing setup. A betslip is not a shopping cart
  • Made both products webview-ready for the iOS/Android apps, debugging the not-quite-a-browser quirks side by side with the app developers
  • TypeScript
  • Vue 3
  • Pinia
  • Node.js
  • Express
  • .NET (C#)
  • Azure
  • Cloudflare
  • GTM
  • Google Analytics

Freelance Full Stack Developer · DPG Media

Mar 2018 – Jun 2022

Built and ran entertainment products: video, puzzles, casual games, quizzes and podcasts. They served roughly 1.5 billion views a year across DPG's biggest brands (AD, HLN, de Volkskrant), with advertising, paywalls and tracking built in, under a "you build it, you run it" principle.

  • Built the embed system end to end: the loader script, the data-attribute element API, and the embeds themselves in vanilla JavaScript, CSS and HTML. Nearly all of it mine, with the team as sparring partners. Carried video from 4 to 20+ titles, then puzzles, games, quizzes and podcasts
  • Implemented the complete Snowplow analytics integration on the front-end: plays and playthrough, profile-based recommendations, and daily-puzzle notifications that knew whether you'd already played
  • Built the web side of the "wall" product: a brand sets up one route with its own header and footer, and we render everything in between. One lightweight integration per label
  • Worked in continuous back-and-forth with the app teams on webview integration; later ported the products to React alongside the React Native apps
  • Ran what we built: containerized hosting in AWS, caching and WAF in Akamai, monitoring and alerting
  • TypeScript
  • React
  • Node.js
  • Elixir
  • PostgreSQL
  • AWS
  • Akamai
  • Snowplow
  • Google IMA

Team Lead Front-End · DigitasLBi

May 2016 – Dec 2017

Led front-end development (75% hands-on, 25% leading) for a team of about 8 front-end developers in a fast-paced B2C campaign environment, for clients such as Audi, Renault, Dutch Railways (NS) and the Ministry of Health.

  • Stepped into the front-end-lead gap from day one. The sitting lead announced his departure the day I started, so in practice I took on the estimations and the back-and-forth with PMs and traffic
  • Defined the common front-end stack and coding standards used across projects and teams
  • Gave a trainee his first production project, trainbooking.com, with direct client contact included, and guided him through it
  • Encouraged a developer to take campaign sites to React, then guided him in building our reusable campaign tooling. In effect our own meta-framework, before Next.js existed
  • Delivered under hard campaign deadlines, including a multilingual Audi site live within four weeks
  • JavaScript
  • React
  • Vue
  • Nuxt
  • Node.js
  • Azure
  • AWS

Full-Stack Web Developer · Hot ITem

Sep 2008 – Apr 2016

Started full-stack in the ASP.NET and jQuery era, building business web applications for clients including PostNL, ING, Rijkswaterstaat, KPN, Ziggo and de Persgroep.

  • Claimed the front-end spot nobody wanted and grew it into a UX practice: user sessions, client presentations, and sparkling interfaces on top of server-rendered pages
  • Kept de Persgroep's news platforms running at 35M pageviews a month, a big number in 2010
  • JavaScript
  • C#/.NET
  • PHP
  • Java
  • SQL

Skills

Expert
  • TypeScript / JavaScript
  • HTML
  • CSS
  • Node.js
Specialties
  • Server-side rendering (custom-built, at scale)
  • Analytics & experimentation (GA, GTM, Snowplow, A/B testing)
  • Embeds & webviews
  • Monitoring & alerting
  • Accessibility (WCAG)
Comfortable
  • C#
  • Elixir
  • SQL
  • Any language with an expert on the team. I ask, I learn
Frameworks & platforms
  • React
  • Vue
  • Next.js
  • Nuxt
  • .NET
  • Phoenix
  • Azure
  • AWS
  • Cloudflare
  • Akamai
Beyond code
  • Explaining technology to non-technical people
  • Translating abstract ideas into structured processes and UX
  • Data modeling
  • Refining requirements
  • Mentoring & sponsoring engineers
  • Working in agile teams

Education

  • MSc Information Science: Human Centered Multimedia, University of Amsterdam · 2015
  • BEng Business Engineering, Inholland University of Applied Sciences · 2007

Off the clock

Right now I'm building a log cabin in the backyard, my team of three kids and I report to my wife, and I'm over-engineering a meal planner, because deciding at 17:00 what's for dinner is the mental equivalent of driving your car into a ditch.