René Weteling

CV - René Weteling
Freelance | Tech lead | Fractional CTO | Problem solver | Full-Stack development

Naam René Weteling
Adres Johannes Geradtsweg 47, 1222PM Hilversum
Telefoonnummer +316 (0) 55 128 199
Portfolio www.weteling.com
E-mailadres rene@weteling.com
Geboortedatum 04-12-1986
Geboorteplaats Capelle a/d IJssel
Nationaliteit Nederlands

Over mij

Van jongs af aan ben ik altijd geïnteresseerd geweest in computers, scripting en automatiseren. Dit begon toen ik klein was met het maken van menu's in MS-Dos, gevolgd door zakgeldberekeningen in Works Sheets, en later het bouwen van een digitaal roostersysteem voor de pizzeria waar ik werkte toen ik 16 was. Logischerwijs heb ik dit pad voortgezet en ben informatica gaan studeren, waarna ik bij een design agency terechtkwam.

Het leuke aan het werken bij een design agency is dat je projectmatig werkt en met veel verschillende aspecten van IT in aanraking komt. Dit voedt mijn brede interesse: van teamdynamiek en programmeren tot devops en advies; ik doe het allemaal graag.

Maar de echte sprong in mijn ontwikkeling kwam toen ik ben gaan freelancen. De verantwoordelijkheid die je voelt voor een project zorgt ervoor dat je scherp bent en wilt presteren. En deze mindset is uniform voor freelancers, je pusht elkaar echt naar een hoger niveau.

Vaardigheden & Kennis

Hier heb ik mijn meest prominente vaardigheden uitgeschreven.

Talen & Frameworks
- De Nederlandse taal
- De Engelse taal
- Elixir (Phoenix)
- Ruby (Ruby on Rails, Sinatra)
- Javascript (ES6, Typescript)
- Python (vooral nog hobby, maar zou er graag meer mee doen)
- Front-end frameworks (VueJs, Pinia, Ionic, React, Turbo, Stimulus)
- Databases (MySQL, PostgreSQL, SQLite, MSSql)
- Message queues (Kafka, RabbitMQ, Redis)
- NoSQL databases (MongoDB, PouchDb, DynamoDB, Redis, ElasticSearch)
- Styling (Sass, Scss, Less, Css)
- Git flavors (Github, Bitbucket, Gitlab, Azure DevOps)
- Projectmanagement (Scrum, Agile, Clubhouse, Flow, Asana, ClickUp, Jira, Azure DevOps, etc.)

DevOps
- Terraform (AWS-flavor)
- Hosting platforms (Heroku, Dokku, Docker, AWS, K8s, GCloud, Azure)
- AWS (Fargate, S3, Route53, Beanstalk, EC2, RDS, ECR, etc.)
- CI/CD (Github Actions, Gitlab, CircleCi, Travis)

Architectuur en ontwerpprincipes
- C4 model architectuurontwerp
- Reactive programming
- Gedistribueerde high-load applicaties

Educatie

The Coding Gnome
2019 Elixir for programmers

Bureau Spraakwater
2018 Cursus spreken in het openbaar

Hogeschool Rotterdam
2004 - 2010 Bsc, ICT

IJsselcollege
1999 - 2004 Havo, Natuur en Techniek

Werk, projecten en ervaringen

Lektor B.V.
Technical lead
01-02-2026 - Heden

Leading the (re)build of Lektor.nl, taking the strongest elements of the current platform and re-architecting them into a future-proof, scalable system. The focus is on creating a flexible foundation that enables new product ambitions while remaining robust under growing demand.

Responsible for technical direction, architecture decisions, and implementation using Next.js, Zenstack, Zod, and shadcn/ui — building a modern, maintainable SaaS platform designed for long-term evolution.

Bravoure B.V.
Interim Technical director
01-08-2025 - 30-11-2025

Bravoure is a digital agency focused on crafting pixel-perfect, impactful digital experiences for well-known clients.

When the team ran into capacity challenges and decided to separate development from strategy and design, I stepped in to help drive that transition. I managed the process, help solve acute delivery challenges, set up practical processes that stick, and provide hands-on technical direction for new and existing projects.

WAT.WORKS - Beschikbaarheidswijzer.nl
Principal Developer
01-02-2025 - Heden

I support Wat Works as a part-time technical coach, helping their internal team design and set up a production-ready SaaS platform. Drawing on 20 years of experience, I guide the initial architecture, coach developers on modern practices, and provide hands-on feedback — focusing on building a team that can sustainably develop and evolve the product themselves.

Truely Travel eSim
Sr. Elixir developer
01-10-2025 - 20-02-2026

Truely is a quickly growing e-SIM company, providing connectivity for people on the go. The backend is written in Phoenix, and this is where I come in. Helping out with fortifying the code-base, building new features, optimizing flows etc etc.

TommyTomato
Delivering healthy hot school lunches
12-04-2024 - 17-08-2024

TommyTomato has a mission to turn all children into lifelong vegetable eaters. Plant a seed, harvest a healthy generation. They achieve this by bringing healthy, hot, and above all tasty lunches to schools. This involves a considerable amount of logistics; all lunches must be delivered hot and on time.

TommyTomato is growing rapidly, so much so that the current IT landscape cannot handle this demand. That's where I come in.

From a Ruby monolith with performance issues, we are transitioning to a monolith prepared for a reactive event-based services structure, with the ultimate goal of rewriting everything into Python microservices driven by a queue (Kafka).

My tasks include making the Rails app future-proof, rewriting it into a services architecture, setting up CI/CD, deploying pipelines, and setting up AWS infrastructure with Terraform. And many more things.

Beam
Integrating gaming with blockchain
01-08-2024 - 31-07-2025

Beam is a blockchain platform focused on supporting a diverse ecosystem of projects spanning gaming, AI, and decentralized finance (DeFi). The platform features a Layer 1 blockchain secured by Beam Nodes, and incentivizes participation through staking and validation rewards, resulting in a thriving community of developers, users, and projects.

As Head of Engineering, I led a team encompassing engineers, DevOps, QA, and support, prioritizing rapid iteration on new concepts driven by emerging market and community opportunities. This involved periods of intense activity followed by periods of rest. While the team was comprised of both senior and junior engineers, already possessing strong best practices, my role focused on providing guidance where necessary, removing unnecessary constraints, coordinating with stakeholders on design and rollout plans, and maintaining team morale and motivation. This was an exceptionally rewarding and enjoyable assignment.

Semmie.nl
Asset management simplified
02-10-2023 - 11-04-2024

Semmie is an asset manager where clients can easily open an account. Through a smart questionnaire, the associated risk profile is determined, and Semmie actively manages the investments. Clients can control everything through the app or online portal.

Semmie also offers the option for advisors to set up all of this through the advisor portal.

In the vast landscape of Semmie's tech infrastructure, I find my focus within the intricate layers of the CRM backend, API, (Mobile) App, and Advisor portal – essentially, the tech heartbeat of our operation. My current playground is the backend, where I'm actively shaping and enhancing features for the Rails API and App. Simultaneously, I'm deeply immersed in setting up DevOps resources, collaborating seamlessly with Azure.

Addressing the historical separation between the frontend and backend teams, my goal is to close the gap, encouraging cross-functional collaboration, and ultimately forging a cohesive, unified team. Let's seamlessly merge these tech realms into a singular, synergistic force.

Odido / T-Mobile
TSC - Business router gui's
01-11-2021 - 28-09-2023

Odido, formerly known as T-Mobile, has a digital realm that extends beyond what meets the eye. As a developer in the company, I have the opportunity to think like an architect, considering responsibilities, data storage, and optimal placement. It's an engaging and enriching experience.

I am currently a member of the Red team in the Operational Support Services department, consisting of three RGB teams. Our primary focus is to create, manage, and support operational services to ensure the seamless functioning of our entire service portfolio. With over 18 applications to oversee, ranging from Node.js and Ruby on Rails to Elixir and Bash scripting, my team plays a critical role in maintaining their uninterrupted operation.

DPG
Media backbone for media outlets
01-11-2019 - 29-10-2021

MyChannels is a division within DPG Media group that is responsible for all digital content on all digital outlets of DPG. Ad.nl, Volkskrant.nl, Hln.be, Trouw.nl, Parool.nl and so on. The team is compact, senior and knowledgeable. We are responsible for more than 5 million video plays each day. Creating services to supply the media outlets with videos, games and entertainment. Providing the mobile API for the apps of the papers. And so on.

As a full-stack developer I've worked on the backend, mainly in Phoenix and Ruby on Rails, created new interfaces inside of the videoplayer using React, Svelte and Typescript. Changed styling for new brands. Added schema changes. In the last 6 months my focus was on infrastructure, moving from manually created infra to Terraform, implementing security best practices and making the whole infra more robust and flexible.

Re:turnista
Parcel return software
01-02-2019 - 28-02-2019

Re:turnista is an app where clients of webshops can return items they bought. Using a mobile first app, the user is guided through a couple of questions and the package is ready for pickup.

As a full-stack dev, I was tasked to give the current architecture some love to make it more performant. We removed all the custom form logic and implemented a package called Formik, changed the event structure to work more with reducers. Overall cleanup and modularizing of the system.

Zwitserleven
Client portal for pensions
01-03-2019 - 31-03-2019

Vivat is the mother company of Zwitserleven. Vivat has a "My" environment where clients can log in and see information about their products. My team was responsible for the Pension funnel.

As a front-end developer, I changed the loading system (basically the system contained multiple systems so a dynamic loader was needed, especially with varying backend services). Created small updates, and fixed some tickets.

DigiB
Chemical e-trading system
01-04-2019 - 31-10-2019

DigiB is a division of Brenntag. Brenntag is market leader in the supply of raw chemicals. DigiB is tasked with the digital transformation of Brenntag by bringing an e-commerce system, internal trading and couplings between all offices.

As a front-end developer I've worked with the front-end team to expand the e-commerce system built in React, with Next.js and a Node.js middleware. I've also been working on the "target architecture", an overcoupling system that is able to connect multiple ERP systems like Oracle, SAP, Salesforce etc. This design was Reactive using a message bus.

Ace & Tate
Backend ecommerce system
28-05-2018 - 31-01-2019

Ace & Tate sells glasses online and offline, they have "currently" over 30 stores world wide and they use an e-commerce platform (Solidus) to process all orders. Since the company continues to change, the backend also needs to be quite versatile.

As a full-stack dev, I was tasked to optimize and add features to the Solidus powered Ruby on Rails backend. For the consumer and POS facing this was mostly an API. For the internals there was an Admin section and for the internal Friends and Family there was a complete suite with admin panel implemented. I helped maintain over 30 gems, used Elastic Beanstalk for running the app, and increased the test coverage overall.

Tankey
Admin interface including API for gasoline loyalty program
22-01-2018 - 27-04-2018

Tankey is a loyalty platform (LP) created by Essent for their other brand EnergieDirect. The first version of the LP was built within Essent. Meaning that linking other companies proved to be difficult, that's why they split up Tankey from Essent and started building a new and better version of the app.

As a backend developer I was tasked to build an API for the Tankey Android app, build an admin interface where the business can see KPIs, create exports and get the correct insights in what the app is doing. Build a stable and auditable system concerning the new GDPR ruling. Create API couplings between Firebase for in-app notifications. Create a discount calculator module. And integrate loyalty partners through our API.

ABN Amro
Cybersecurity awareness app
04-12-2017 - 25-01-2018

The Main Ingredient was tasked to help out the CyberSecurity department of ABN Amro with creating more awareness for cyber threats for small companies. Think of phishing emails, certain new techniques that they have spotted or even social engineering. TMI came up with Veiligzondermoeite.nl, an initiative to inform the general public.

As a full-stack developer, I was asked to lead a team of highly skilled developers and designers to create in just 6 weeks a working POC of the app. The app was built in ReactNative, the backend in Node.js using Express as server layer and deployed on BeanStalk using a CloudFormation template. We also hooked up an RDS instance for our persistence. My main focus was in creating the backend and helping out with the ReactNative app. The team was excellent in styling / creating components, my assistance was most needed in hooking up the APIs.

BotSquad
React - Webpack - Jekyll
16-10-2017 - 17-11-2017

With the BotSquad bot, you can create bots for the web, mobile and chat interfaces like facebook, slack, twitter etc. There is a beautiful studio where you can create bots using a friendly and semantic DSL. And preview the bot in real time.

- React coding on the Chat client
- Creating the API
- RnD on the bot itself
- Adding features

HalloRoos - SNS experiment
Rails - Roos API - Heroku
11-10-2017 - 08-11-2017

HalloRoos is a contract alarm platform where users can set alarms for contracts that will expire in the future so that they can switch providers on time. HalloRoos was looking to extend their functionality and needed a developer to help them reach their goals. The subject itself is somewhat sensitive, but it comes down to a pretty selection then order flow with alot of validations and constraints. Each step is communicated to an API provided to store and manage the data.

- Build the pages as described in Rails using Slim, Sass, and CoffeeScript
- Connect the pages to virtual models so that we can apply validations
- Persist the validated models to the provided API

Van Ons B.V. - Carpet App
React - LibVips - OpenVc - DeepZoom
02-06-2017 - 13-09-2017

Van Ons is a really cool WP design agency based in Amsterdam. For some projects, they contract out for special features and this was quite special. They wanted to create a web interface were clients can cut out a portion of a really big image (30 by 30 meters at 76 dpi approx 46GB per image). So I've developed a React frontend where the users can walk through the image using DeepZoom. And cut out a shape and then sending the coordinates to a worker server, cutting out the piece and mailing it to a carpet printer. Pretty heavy stuff.

Everything was new, everything was exciting, it was an awesome project.

- Build a react app to define the area that needs to be sliced
- Create a slice worker server that slices the image according to the dimensions provided by the react app
- Figuring out how to slice images as big as 46GB each

Revolve Music
CTO - Rails - AWS - CI - rSpec
03-04-2016 - 15-09-2017

Revolve Music is a SAAS platform where users (Artists mostly) can create a website, a digital presence in just a few minutes. Connecting to filled content providers like SoundCloud, BandsInTown, LinkedIn, Twitter etc your site is filled with content and you are ready to go.

- Clean up and rebuild existing code (the overall quality was very poor and not very robust)
- Create a Continuous integration environment using CircleCi and AWS container service
- Creating a global scaling web server setup using: Route53, AWS EC2, AWS EC2 container service, Cloudfront, RDS, S3 and Docker
- Being responsible for the Technical day2day, building team culture, applying standards, laying out technical roadmaps etc. CTO stuff.

Leaplines
Onboarding software for large companies
01-05-2015 - 01-02-2016

Leaplines is a SaaS that helps companies with their on-boarding process. Providing a curriculum based on the employee's role within the company, with a clear hierarchical method of stimulating the users through there managers.

We made use of the following: Rails, PostgresSQL, CircleCI, Github, Rspec with Capybara ( TDD ), jQuery, React, Rails UJS

- Going to clients, getting feedback from the source
- Building new features, mainly onboarding exercises in for form of a game
- Scrum plannings etc

Horyon innovaties B.V.
Android process app, Rails backend
15-10-2015 - 01-09-2022

Horyon innovaties B.V. is an asbestos removal company. Asbestos has a bad reputation and that's why there is a lot of legislation. They are required to have all data on premise at all times. This is just not possible on paper, so we have created a Rails backend with a Restful api connecting an Cordova Android app. The app started out as a simple hour measuring platform, but now it has over 18 main functions and one of them is drawing on a photographed map.

- Design the product matching the needs of the business
- Creating a Rails backend, with role based authorisation
- Ops: it runs on my own High availability cluster powered by Flynn.io
- Creating the React Cordova android app

Click.nl - employed
iOS, cordova and react development
01-07-2012 - 01-04-2015

Coming back to click felt really good. They had so much faith in me that they wanted to set up a new office in Amsterdam with the main focus on Mobile. We had some really great clients. We have build an app for KPN where users can view the last goals in a soccer league. Build an app for a recruitment agency and many more.

Overstappen.nl - employed
Symphony - Php - Less
01-08-2011 - 01-07-2012

This is the first time i got in contact with a proper framework. Symphony. It's mature, it has a rich plugin ecosystem, its consistent. I liked it allot. Learned a lot here, the main issue was that i was the only dev in the company so i got a bit bored and moved on. Great experience though.

Click.nl - internship then employed
Perl - CaretCMS - Scripting - Discovering
01-12-2008 - 01-08-2011

My internship at Click.nl was great, a young team, cool founders, nice environment and Dirk the dog. I've learned so much here, multiple languages, dynamics in the company's themselves. Learned about budgets, stakeholders, planning etc. It was a great experience.