As an engineer, product manager, engineering manager, architect, CTO (phew), I’ve been involved in building a fair few projects in my career. Linkedin profile here:

Jonathan Holloway on Linkedin


I spent a fair amount of time in the eCommerce world building the following: Booking engines for travel, online ordering of products - fair amount of front-end; Integration (Java/Python) for product information management (PIM), search engines (Bloomreach, Endeca), order processing and warehousing. Mixture of hand-rolled as well as Camel and Mule. Storefont integration (too many times) for Magento, Elasticpath. I did training for Commerce Tools in 2020 on the platform. Most of this was Java based. ERP system integration at scale for 1500+ businesses with Brightpearl. High-scale order processing with Java, Spring, several database vendors including optimisation with caching, orchestration of workflow/state machines, failure handling and backoff. General systems architecture - what to do (monoliths rock, limited service archtectures) and most of the time avoiding or rebuilding micro-service architectures that have become peoples playgrounds for learning (Don’t do it unless you really really have to in short).

Assessment & Education

Pedagogy, assessment and education were the original components of my research degree, initial PhD then writeup as an MPhil. As part of that, much of the research around “how we learn”, “what works for individuals” and “how we assess individuals” on taught subjects was built out in a piece of software and a founding company in the education space. That was enterprise software (Java, Postgres, JEE) offered to high-level educational institutions - universities etc…. In retrospect, it should have been much more lightweight and focused in the data space. I’ve also built out several skills analysis and visualisation tools in Python (Jinja, Flask), Javascript (Express, Node.js) to look at career growth within the software industry for engineers and managers.

Financial Services

Most of my financial services work has been Java based involving integration platforms or hand-coded Java/Spring stacks. This has included: Archiving, compliance and search software in the banking space for legal and trading purposes; Financial services messaging platform with ethical walls etc… Open Banking platforms (Plaid et al…) and nifty data work parsing transactions with Python, Docker and BigQuery. Payment Service Provider integration (via aggregators or direct) having to implement several financial services standards and protocols (standard pre-auth/auth, 3D Secure). This also included building several desktop applications to allow internal staff to manage payments/refunds/alterations.


Various projects including building out drug modelling and analytic platforms for Merck, J&J, Bayer and Boehringer. Built out workflow and integration engines for statistical tools (NONMEM, PsN, R, SAS, Matlab) and distributed grids and load schedulers (Sun Grid Engine, LSF etc…). Most of the integration work was in Python (good choice), Java and Bash were ultimately the wrong choice here due to bloat, development efficiency and escaping processes to run shell commands. Insight into Patient Record System (mostly ERP for healthcare) and integration with several back-office systems. Warehousing etc… Built out a mental health platform attempting to use Cognitive Behaviour Therapy to treat people online in the German market. Short story - they didn’t validate the idea, couldn’t sell it and spent waay too much money on poor SEO keyword choices. Shipped the first product in six weeks on Wordpress, Zapier, PHP and Zendesk (with lots of glue). Rebuilt that in Kotlin services with a React frontend then they ran out of money.


Lots of projects involving mostly data-engineering, but also a reasonable amount of data-science work. Spent a fair amount of time of this on the Google platform (GCP), did the data-engineering training and BigQuery architecture and administration training. Built some things on Tensorflow and pipelines based on Beam. Most of this was Python and Java. Lots of reporting dashboard builds and moving customers off Excel and SAS onto modern day tooling. Javascript dashboards and custom builds with Chart.js and Plot.ly. Built tools in Python and R for statistical data work. Built a performance and load testing analysis tooling in R , Python and Bash.


Re-architecture and re-platforming of a prop-tech/insurtech platform and various integrations with insurance systems. Most of the work was Javascript/Typescript based with a data-platform written in Python utilising BigQuery, Firebase and pipelines on GCP.


Brief foray here (around six months) overseeing a team and platform in the ad-tech world that integrated with various real-time bidders (mostly C), data platform written in Scala (don’t ever use it). Wasn’t that hands-on with the architecture given the problems going on, but good understanding of how geo-location, data pipelines, real-time bidding and time-series, column family, relational database archtiecture and real-time bidding dashboards work. Projects with McDonalds and fair few big names.


Booking engine and associated integrations for Flybe.com circa 2004 - 2007. Lots of high-scale website bookings, ticketing, ancillary sales and integration with Java and Struts at the time. Replatformed onto Spring, moved payment systems to Datacash and introduced 3D Secure. Prior to Airbnb, we launched Sanctuary 7 (circa 2006) as a luxury destination and holiday home for end users to book on a weekly/monthly basis. This was a PHP platform with Postgres backend including appointment and payment integrations.


Several solutions in the community space. First in the music space, then in the toy and software space to support users wanting to trade, sell and buy within communities.