Jonathan Holst Résumé

Contact

Email

[email protected]

Website

jonathanholst.com

LinkedIn

jonathanholst

Summary

Senior software developer with 15+ years of experience building and shipping end-to-end products. Proven track record of delivering measurable business impact through product-focused engineering across multiple companies, from startups to established companies. Experience scaling platforms from zero to tens of thousands of users, navigating and contributing to nascent business plans, as well as driving profitability improvements through strategic technical decisions for established platforms.

Current

I am currently working as CTO at GreenMobility A/S.

Skills

Work experience

1. GreenMobility A/S (2023–)

   Formal job title: CTO.

   • Rejoined to take up the role of CTO after a brief stint at GAN Integrity
   • Responsible for the entire tech organisation, including internal product management, software development and IT operations and managing key external technology vendors
   • Part of the executive management team, responsible for setting the overall direction of the company
   • Mentoring developers, including architecture and code reviews and internal knowledge sharing sessions

   Project highlights

   • Set up a remote 2-person development team in Egypt
   • Finalised a stalled project to implement a new invoicing logic, working with key stakeholders in Finance department and outside legal consultants to identify remaining blockers and get those rectified, improving profitability of the company. (In the first full fiscal year after my return, the company went from net losses to net profits)
   • Defined and implemented a project to save the company's use of expensive SMS messages by 90% (~$170,000 per year), with no loss to the customer experience
   • Negotiated a new contract with a key technology vendor that both defined deliverables and improved pricing terms
   • Implemented automated code quality gates in CI pipeline, improving developer experience and reducing code review overhead

2. GAN Integrity (2023)

   Formal job title: Tech lead.

   • Joined as tech lead of the User Management Squad with managerial responsibilities for a team of 3 developers. My tenure was very short, however, as I was headhunted quickly after joining
   • Was part of the cross-organisation tech lead group that helped set the direction for the tech organisation

   Project highlights

   • Implemented automated dependency updates in the CI pipeline
   • Introduced the concept of a technology radar as a technology decision framework

3. GreenMobility A/S (2021-2023)

   Formal job title: Senior backend developer.

   • Joined at the scale-up stage as an experienced hand to contribute to an existing system, serving as a de facto second in command to the CTO (including being effectively interim CTO during his parental leave)
   • Built and maintained backend GraphQL and RESTful APIs for use by internal frontend clients as well as third-party service integrations
   • Built and maintained data pipelines in Node.js ingesting data from key third-party systems into the company's own infrastructure and data warehouse
   • Built and maintained React components and pages in Next.js
   • Mentored junior developers, including architecture and code reviews and internal knowledge sharing sessions
   • Helped institute software development practices such as feature flagging and increased the focus on automated testing.

   Project highlights

   • Architected and implemented a system for rewarding customers charging the vehicles, improving operational efficiency and customer loyalty
   • Architected and implemented the backend of a real-time notification system of vehicle availability in the user's area, saving people with flexible schedules from constantly checking the app for available vehicles
   • Architected and implemented a system that evaluated thousands of trips per day for any relevant bridge/congestion fees, saving on operational costs and improving customer experience by timely and correctly billing for actual use
   • Salvaged a stalled project to implement a new payment logic for company's vehicle reservation system
   • Revamped end-user booking flow for improved usability
   • Split monolithic monorepo into smaller services and libraries with Turborepo

4. Veo Technologies ApS (née Sportcaster) (2016-2021)

   Formal job title: Senior software engineer.

   • Joined as employee no. 7 to head up development of its web properties
   • Built and maintained HTML, SCSS and vanilla JavaScript web pages with Django backend services
   • Built RESTful service-to-service Python backend APIs and consumers

   Project highlights

   • Started and developed on the customer-facing platform (full stack), continually iterating on the best way to make use of an imperfect AI output. The platform grew from 0 to 50,000+ of users during my tenure, and still serves as the foundation of the company's online software offering
   • Enabled remote camera operation via a web app served from the camera
   • Architected and implemented the event-based video processing pipeline that took recordings from cameras through intermediate steps of AI inference, video rendering and transcoding, human QA all the way to final publication in the hands of customers
   • Set up feature flagging system to allow for gradual rollouts of new features
   • Implemented complete CI pipeline with automated testing, coverage tracking and linting, ensuring high code quality across the codebase

5. Ovivo ApS (2011–2013) / PDC A/S (2013–2016)

   Formal job title: Lead developer.

   • Joined Ovivo as employee no. 3, the first developer to get the company off the ground. Continued leading Ovivo development after PDC's acquisition in 2013, while also contributing to other PDC properties
   • Wrote most of the code for the Ovivo platform that captured significant market share in Denmark's primary care sector: A Django-based backend (PostgreSQL database, Redis caching layer, Celery for asynchronous processing) with HTML/CSS/JavaScript (jQuery) frontend using WebSockets (via Socket.IO) for real-time updates
   • Served as lead developer for a small global team of remote developers

6. Early career (2004–2010)

   Web developer at Print2People ApS, ToonPrint A/S, Verk ApS and GMTA ApS

Education