Hi, my name's Jack.

I'm a senior fullstack developer with more than 7 years experience. I live in Berlin, have founded my own successful startups, and worked for Silicon Allee's biggest brands. I'm currently considering contracts in Berlin.

Hall of fame

SoundCloud, Fullstack

Senior fullstack developer. Used Scala, NodeJS, Golang, React and Rails to serve over 50k requests per second and 150million users.

GoEuro, Backend Lead

Backend developer working on APIs and Payments using Java, Scala, Spring, Play, Mongo and Postgres.

EyeEm, Fullstack Lead

Planned and implemented a fullstack rewrite of the EyeEm web platform building a responsive isomorphic React app for 20million users.

Notable contracts

Boston Consulting, Senior Backend

Took a lead role with BCG's Digital Ventures division building backend application for realtime farm analysis. I wrote software in Go, Spring, and Node that directed self-driving tractors and analysed the chlorophyll count of crops via satellite imagery. It was a fantastic experience.

Croove, Senior Backend

Senior backend for Daimler's car sharing service Croove. Built using Scala, AKKA, NodeJS, Golang, AWS SNS and Lambda.

Geeny, Backend

Backend developer at Telefonica's German IoT branch, Geeny. Built an IoT gateway using Scala, AKKA, NodeJS, Golang, AWS IoT and Lambda.

Main skills

Java, Scala, Spring, AKKA, NodeJS, ES6+, Vue, React, Angular, Golang, Rails, Python, AWS, Docker, SQL, Mongo, CSS3, HTML5, UNIX, Android, communication, pragmatism, confidence, and learning new systems.

Companies founded

Invoicing for developers

After 4 years of consulting and freelancing, I felt that invoicing was broken. That's why I created CommitSheet, a free invoicing service for developers. Devs already leave a detailed history of their work in Git; why not convert that to detailed invoices automatically each month? It saves developers hours and gives recruiters and clients exactly what they want.

I'm super proud of CommitSheet as I built every aspect of it over a 2month period and see it as a culmination of everything I've learned in the industry. The stack is Vue, Typescript, Node, Spring, Java and runs in Docker containers via AWS ELB. It uses Stripe for payments, Github for user integration, Postgres for data storage, and Sentry, Mixpanel, and GA for tracking. I also handle design, media, SEO, and support for this project and have learned a lot in the process. These days however the company runs itself and I simply handle support and bugfixes. That means it will not affect my productivity in contract roles.

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E2E email testing API

Born from a problem I encountered during a contract role, MailSlurp is a free email testing API that let's users send and receive emails from randomly generated inboxes on demand. It relies heavily on AWS SES, SQS, S3, Cognito, and Lambda. The API itself is written in Spring Boot and the webapp is Node ES6+ Express.

The service has been a hit with users and has tested my dev ops skills. It handles a lot of requests and performs several cron tasks so uptime was very important. With Lambda and ELB MailSlurp achieves 99% uptime.

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3D modelling is my hobby. I built a paid Saas 3D rendering service in Scala AKKA and Play with Firebase and Stripe. It let's users upload 3D files and render them on AWS EC2 GPU instances through a web interface. It then saves rendered imagery to S3 and syncs with the user's Dropbox.

I made every aspect of 3DRC, from the design and development to the marketing and legal paperwork. It took a lot of planning and skill to pull off and was profitable. I have since paused development on 3drendercloud in order to release a more generic version that supports a wider range of 3D software.


A free, private, secure VPN for Chrome. When enabled it routes requests through American and British servers so that users can browse from those countries. It is profitable via affiliate linking.

I designed MakeMe's look and message, built the website and Chrome extension, and developed the infrastructure. MakeMe VPN is currently available in the Chrome store and has received great reviews.

View project


AtFarm (BCG DV), Senior developer (Contract)

Java, Spring, GoLang, AWS

In 2018 I joined a Boston Consulting Group Digital Venture called AtFarm. This was my most exciting venture to date and involved programmatic analysis of satellite imagery to improve crop yields on farms.

I was in charge of bootstrapping the API in Spring Boot and also implementing instruction sets for self-driving tractors in GoLang. I had to read a full ISO specification of a closed-source tractor instruction system and then write code to convert our farm analysis data into driving commands. I was even trusted with flying to Norway to test out the code on a real tractor.

February 2018 - May 2018 (Contract)

GLS Labs (GLS), Lead developer (Contract)

Java, Spring, React, Typescript, AWS, SES, SQS

I was hired as a lead developer for an experimental project at GLS Postal Service's tech venture GLS Labs. I bootstrapped the project, hired other developers and managed a team of three. The project itself involved a SPA, API, and email parsing technology. Details are covered by NDAs but it basically aimed to replace mail rooms at large companies. It was a great challenge.

October 2017 - January 2018 (Contract)

Croove (BCG / Daimler), Lead backend developer (Contract)

Scala, AKKA, NodeJS, GO, AWS, Firebase, Postgres, Mongo, SNS

I worked as a contractor for Daimlers mobility startup Croove. letscroove.com allows people to rent cars from other users in Germany. I wrote APIs for payments, bookings, and customer service using AKKA, AWS SNS, Go, Scala, and NodeJS (Flow). I also assisted in hiring. The company was acquired by Turo in October.

July 2017 - September 2017 (Contract)

3drendercloud.com, Founder

Scala, AWS, Firebase, Postgres, Windows Server

I left startups to start my own. I built a profitable online 3D rendering service called 3drendercloud. I created every aspect of it, including design and marketing campaigns. The infrastructure is built in Scala Play and AKKA. It dynamically allocates AWS EC2 GPU machines to customers and remotely runs rendering software on them. It was a fantastic learning experience. I advertise with Google Adwords, Facebook, Youtube and Twitter. I handle payments via Stripe and logins via Firebase. Everything else is done programmatically in AWS.

April 2017 - ongoing

Geeny (McKinsey /Telefonica), API and IoT developer (Contract)

Scala, Java 8, AKKA, NodeJS, AWS IOT, Firebase, Postgres, Mongo, Lambda

I worked as a contractor for Telefonica Germany's R&D offshoot Geeny. I wrote APIs in Scala and Node that managed a complex IoT ecosystem of custom hardware built on the Amazon IOT platform.

January 2017 - April 2017 (Contract)

SoundCloud, Fullstack Engineer

Scala, Java, NodeJS, Golang, Ruby

I wrote Scala APIs and Node applications on an epic scale at SoundCloud. With over 150million users and hundreds of microservices, code had to be well tested and of the highest quality. I learned invaluable skills in communication, code quality, infrastructure, and debugging large applications. I became the lead developer on the Core Web team responsible for 150 servers and the code behind soundcloud.com.

April 2016 - January 2017

GoEuro, Senior Java API Developer

Java, Scala, Spring, Play, AKKA

GoEuro is an agile and energetic Berlin startup that brings bus, train, and air travel together in one place. I worked as a senior backend Java engineer designing and building a brand new RESTful API, which was consumed by many applications and thousands of users daily. It also handled tens of thousands of euros in payments and had to be extremely secure and robust. It called many external parties, and dealt with sensitive information such as addresses and payments. It was a critical system, so bullet-proof testing and clear code planning were paramount.

February 2015 - October 2015

MoreSleep, Tech Lead (Contract)

DevOps, Wordpress, Docker

I served as Tech Lead at the Berlin digital agency MoreSleep. I assisted in hires, managed the developer team, scoped projects, and lead development. I also used my experience in larger companies to modernize the studio's workflows and implement new development and deployment architectures.

October 2015 - March 2016

EyeEm, Fullstack Node Engineer

NodeJS, React, ES6, Flux, PHP

EyeEm is one of the most famous startups in Germany. I worked there as a full stack engineer building a NodeJS-React isomorphic single page web app to serve 20 million users. It was a complex project with many challenges around responsive imagery, page load times, and asset size. We succeeded in making a fast and responsive application on all platforms.

June 2014 - February 2015

Monkii, Lead Frontend Developer

Backbone, Angular, C#, PHP, jQuery, Android

Monkii is a leading digital agency in Melbourne were I worked for two great years as lead front-end, mobile and Wordpress developer.

May 2012 - May 2014

Instinct, Frontend and Wordpress Developer

Backbone, jQuery, PHP, Wordpress

Instinct are the makers of the famous WP-eCommerce plugin. I worked on the plugin and gained a deep understanding of Wordpress core and the plugin ecosystem.

December 2011 - April 2012

Computers For People, Android Developer

Android, Java, C#, PHP, Wordpress

Built four enterprise Android apps along with several Wordpress projects.

May 2011 - April 2012

Paperkite, Android Developer

Android, Java

Helped build the official All Blacks Android app in New Zealand.

January 2011 - May 2011

BSc in Molecular Biology with Computer Science

Studied at Victoria University in Wellington New Zealand.

January 2007 - January 2011