Maarten Claes, Developer in Antwerp, Belgium
Maarten is available for hire
Hire Maarten

Maarten Claes

Verified Expert  in Engineering

Bio

Maarten is a seasoned software engineer most familiar with the edtech and event industries. Over the past ten years, he has built products from scratch and scaled them to millions of users and tens of millions in revenue. He has often handled payment and billing flows, working closely with growth and sales teams to hit ambitious revenue targets. Maarten enjoys high-velocity environments with aligned autonomy where goals are achieved effectively and efficiently.

Portfolio

Inflights
Amazon Web Services (AWS), TypeScript, Ruby on Rails (RoR), React, Python...
Datacamp
Amazon Web Services (AWS), Terraform, React, Zuora, Salesforce, Customer.io...
PlayPass (acquired by Weezevent)
Ruby on Rails (RoR), Go, AngularJS, JavaScript, Chef, PostgreSQL, PayPal...

Experience

  • Ruby - 10 years
  • JavaScript - 10 years
  • Python - 9 years
  • PostgreSQL - 9 years
  • React - 6 years
  • Amazon Web Services (AWS) - 5 years
  • TypeScript - 4 years
  • Zuora - 2 years

Availability

Part-time

Preferred Environment

Vim Text Editor, MacOS, Amazon Web Services (AWS), TypeScript, Ruby, Python, React, JavaScript, Continuous Delivery (CD)

The most amazing...

...project I've developed is an NFC-based payment system used by festivals all over the world.

Work Experience

CTO

2020 - PRESENT
Inflights
  • Built out the platform's minimum viable product, which is now used by thousands of drone pilots and 100+ clients to perform drone surveying missions across four continents.
  • Led the development of a drone data quality checking tool, which uses accelerometer and GPS attributes from the EXIF metadata to assess the quality of a set of drone images.
  • Automated the photogrammetry processing pipeline using AWS.
  • Developed an automated pilot matching and quoting engine which takes into account mission-specific requirements, such as airspace regulations, equipment, and flight plans.
  • Created a file management system to make it easy for drone pilots, project managers, and their team members to share large datasets. The system also helped with the product's intra-company virality by encouraging more users to sign up.
Technologies: Amazon Web Services (AWS), TypeScript, Ruby on Rails (RoR), React, Python, Photogrammetry, PostgreSQL, PostGIS, Serverless, AWS Lambda, AWS Batch, Ruby, Terraform, Test-driven Development (TDD), AWS Cloud Development Kit (CDK), REST APIs, APIs, Serverless Architecture, Node.js, Twilio, API Integration, DevOps, SQL, Selenium, Lambda Functions, Docker, HTML, CSS, Mapbox, Next.js, Tailwind CSS, Full-stack, OpenLayers, Sidekiq, Jobs to be Done (JTBD), Agile, Leadership, RSpec, Devise, GitHub Actions, Continuous Integration (CI), Continuous Delivery (CD), Infrastructure as Code (IaC), Heroku, E2E Testing, Cypress, Unit Testing, Amazon S3 (AWS S3), Full-stack Development, Web Development, Software Design, Software Architecture, Back-end, Flask, HTML5, Microservices, Architecture, Swagger, CI/CD Pipelines, CTO, Product Leadership, Elasticsearch, Docker Compose, Requirements Analysis, React Router, Team Leadership, Team Management, Technical Leadership, Scalable Architecture

Engineering Manager

2016 - 2020
Datacamp
  • Started as a software engineer for the core platform, then gradually progressed to manage and coach eight software engineers across the US and Europe.
  • Built the content management UI and API to allow internal teams to launch 200+ courses, organized in version-controlled tracks to 5+ million users.
  • Engaged in hiring tens of engineers as the company grew from 20 to 140 employees.
  • Replaced an internal email service with an event-driven flow via Customer.io, which allowed growth and marketing teams to iterate more quickly over their email campaigns in a data-driven manner.
  • Migrated from multiple payment providers to Zuora for the business to continue to scale and better integrate with Salesforce as it expanded its revenue from B2B.
Technologies: Amazon Web Services (AWS), Terraform, React, Zuora, Salesforce, Customer.io, Ruby on Rails (RoR), TypeScript, Ruby, PostgreSQL, Stripe, BrainTree, PayPal, AWS Lambda, Test-driven Development (TDD), REST APIs, APIs, Serverless Architecture, Node.js, GraphQL, API Integration, MongoDB, Zapier, Stripe API, MySQL, DevOps, SQL, Selenium, Lambda Functions, Docker, Redux, HTML, CSS, Full-stack, Sidekiq, Jobs to be Done (JTBD), Agile, Leadership, RSpec, Devise, Gatsby, Serverless, CircleCI, Continuous Integration (CI), Continuous Delivery (CD), Infrastructure as Code (IaC), Heroku, E2E Testing, Cypress, Unit Testing, Amazon S3 (AWS S3), Full-stack Development, Web Development, Software Design, Software Architecture, Reporting, Back-end, SaaS, HTML5, Microservices, Architecture, CI/CD Pipelines, Elasticsearch, Docker Compose, Requirements Analysis, Team Leadership, Team Management, Technical Leadership, Scalable Architecture

Software Engineer

2013 - 2016
PlayPass (acquired by Weezevent)
  • Developed the payment system's back end and API for use with NFC wristbands worn at festivals worldwide, such as Lollapalooza Berlin and Chile, Clockenflap Music and Arts Festival, and Oktoberfest Mexico.
  • Designed the payment system so it could work offline and synchronize transactions afterward, which was crucial for the system's resilience at remote event locations.
  • Built an easy-to-brand web front end, which event-goers could use to top up their digital wallets before and during events. It was easy to set up for the organizers while reducing the number of top-up stations and personnel.
Technologies: Ruby on Rails (RoR), Go, AngularJS, JavaScript, Chef, PostgreSQL, PayPal, Stripe, BrainTree, Ruby, React, Test-driven Development (TDD), REST APIs, APIs, Node.js, API Integration, Stripe API, DevOps, SQL, Selenium, Redux, HTML, CSS, Full-stack, Sidekiq, Agile, RSpec, Devise, Jenkins, Continuous Integration (CI), Continuous Delivery (CD), E2E Testing, Unit Testing, Amazon S3 (AWS S3), Full-stack Development, Web Development, Software Design, Software Architecture, Reporting, Back-end, HTML5, Microservices, Architecture, Swagger, CI/CD Pipelines, Requirements Analysis, React Router, Scalable Architecture

Full-stack and Mobile Engineer

2012 - 2013
Digiti
  • Introduced behavior-driven development at the company and built several Ruby on Rails apps, including a project management tool, a video hosting service, and a corporate social network.
  • Built an Android application for a 2FA service. Set up automated testing with a mobile device farm and took screen captures while running tests to check for visual issues.
  • Maintained a mobile application integrated with Siebel CRM, which salespeople at a medical company used. Improved stability by fixing multithreading issues in the synchronization logic.
Technologies: Ruby, Objective-C, Android, JavaScript, Ruby on Rails (RoR), Java, Test-driven Development (TDD), REST APIs, APIs, MySQL, Amazon Web Services (AWS), HTML, CSS, Full-stack, Continuous Integration (CI), Continuous Delivery (CD), Heroku, E2E Testing, Unit Testing, Amazon S3 (AWS S3), Full-stack Development, Web Development, Software Design, Software Architecture, Back-end, Architecture, Code Auditing, FFmpeg

Experience

Integration and Migration to the Zuora Subscription Engine

I led the build vs. buy decision to switch to a payments platform that would better integrate with Salesforce and deal with our growing pains. The payment platform chosen was Zuora. I migrated the existing payment flows, subscription data, and payment methods from multiple payment providers without hiccups or disruptions to the business.

Drone Pilot Search Engine

https://inflights.com/
I built a PostGIS-based search engine that could find qualified drone pilots for specific missions, using equipment data, location, airspace information, and project requirements to create proposals with automated pricing, considering all these factors. This made it much more manageable for the company to organize hundreds of drone surveying missions across four continents. It also helped sales win more opportunities by providing quotes much faster.

Payment System for Festival Wristbands

https://www.playpass.be/
I designed a cashless payments API for NFC chip wristbands and various point-of-sale devices at events and festivals. The system was designed to keep operating smoothly during internet disruptions and connectivity issues, which is crucial for remote locations. It also supported various payment providers, allowing event organizers to choose and negotiate rates.

The system is used for festivals and events worldwide, each with tens of thousands of visitors. Customers included Lollapalooza Berlin, Standon Calling, Clockenflap, Oktoberfest Mexico, and Unite with Tomorrowland Barcelona.

Self-serve Quote Flow for Drone Surveying Missions

https://inflights.com/quote
I used TypeScript, React, and OpenLayers to build an interactive map-based interface where customers could order drone flights.

Users can indicate the area of interest on the map and select which deliverables they would like, e.g., a CAD drawing to install solar panels. The application saves this information and matches it with a network of qualified drone pilots. It then creates a quote based on the rates of the pilots and the costs of permits, processing, and travel.

DataCamp's Course Management System

I built out the course management system for DataCamp. The features included flows for releasing courses, the Gamification API for collecting XP, and a version-controlled track management system, which allowed the content team to improve learning paths in a data-driven manner incrementally.

I developed the original iteration of this system and, later, led a team to continue making incremental improvements. The system's features allowed the company to increase learner engagement, which helped learners complete more courses while increasing user lifetime value. More than 200 paid courses have been published to 5+ million users using this system.

Photogrammetry Pipeline for Processing Drone Imagery

https://inflights.com/
I built the photogrammetry processing pipeline at Inflights, which automatically processed drone image datasets uploaded to the platform. I wrote the pipeline's processing logic in Python and deployed it to AWS Batch. The processing jobs were triggered by events coming in via Amazon EventBridge and AWS Step Functions.

Skills

Libraries/APIs

React, Stripe, REST APIs, Stripe API, Devise, Sidekiq, Node.js, OpenLayers, Braintree API, React Router, FFmpeg

Tools

Vim Text Editor, RSpec, CircleCI, Terraform, AWS Batch, AWS Cloud Development Kit (CDK), Jenkins, Docker Compose, Chef, Zapier, GIS, AWS Step Functions, Amazon Elastic Container Registry (ECR)

Languages

TypeScript, Ruby, JavaScript, SQL, HTML, HTML5, Python, GraphQL, CSS, Go, Objective-C, Java, TypeScript 3, Python 3

Frameworks

Ruby on Rails (RoR), Selenium, Redux, Next.js, Tailwind CSS, Cypress, Flask, Swagger, AngularJS

Paradigms

Test-driven Development (TDD), Agile, Continuous Integration (CI), Continuous Delivery (CD), E2E Testing, Unit Testing, Requirements Analysis, Serverless Architecture, DevOps, Jobs to be Done (JTBD), Microservices, REST

Platforms

Heroku, Visual Studio Code (VS Code), MacOS, Amazon Web Services (AWS), AWS Lambda, Docker, Mapbox, Salesforce, Android, Twilio

Storage

Amazon S3 (AWS S3), PostgreSQL, MySQL, PostGIS, MongoDB, Redis, Elasticsearch

Other

APIs, API Integration, Full-stack, GitHub Actions, Full-stack Development, Web Development, Software Design, Software Architecture, Reporting, Back-end, SaaS, Architecture, CI/CD Pipelines, PayPal, BrainTree, Serverless, Lambda Functions, Leadership, Infrastructure as Code (IaC), Learning Management Systems (LMS), Team Leadership, Team Management, Technical Leadership, Scalable Architecture, Code Auditing, Zuora, Customer.io, Photogrammetry, Gatsby, Caching, A/B Testing, Amazon EventBridge, CTO, Product Leadership

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring