Crafting remarkable software products and helping teams do the same. Former CTO, from product design to production ML. Booking contracts or looking for gainful employment.
Hi, I'm Simon 👋. I help companies design and build software products that work. I'm actively looking to work with smart and conscientious people, and companies that have a net positive impact on the world. I have experience from fine-tuning LLMs to leading teams, to designing and shipping complete products.
Recently: implemented an ML project for NOSIBLE, fine-tuning Qwen3 to match GPT-5.1's accuracy on financial sentiment classification at a fraction of the cost. Models and datasets are open-source on HuggingFace.
Before that, I spent three years as a vested CTO at Wealthbit, a FinTech startup on a mission to get a million South Africans to financial health. I built and led the engineering team, and from early 2025 grew a completely new product packaged in a mobile app from concept to production.
My background is peculiar: I've led teams, designed products, shipped frontends and backends, and now I'm deep in ML. I'm most useful when a project needs someone who can move fluidly between strategy, implementation, and the messy bits in between.
I studied Computational Intelligence (Honours, Cum Laude) at the University of Pretoria. Over my career I've spoken at conferences in the US, UK, and South Africa on topics including chatbots (before they were cool), cancer diagnosis with machine learning, and software design. See simonvandyk.info/speaking for details.
When I'm not developing software, I enjoy making good food and coffee, playing guitar for my son, or taking photos.
Currently looking for a place to work (contracts or employment) with smart and conscientious people to do something significant. Based in the UK, remote only.
Developed three production text classifiers for financial sentiment, forward-looking statements, and predictions. Fine-tuned Qwen3 0.6B to match GPT-5.1 accuracy at orders of magnitude lower cost.
Implemented an active learning pipeline for label refinement using LLM ensembles
Fine-tuned models on GPUs using PyTorch and HuggingFace Transformers
Open-sourced all models and datasets on HuggingFace (NOSIBLE org)
Built clinical decision support features for my previous employer, Fora Health, a patient engagement platform used in the NHS and private healthcare settings. Engaged across multiple contracts over two years.
Developed a RAG system integrating private medical literature databases enabling patients to ask natural language questions about their conditions and receive referenced, evidence-based answers
Built a clinical decision support tool for care teams that combines prescribing guidelines with patient data to surface relevant recommendations and visualise decision flowcharts
Designed and implemented a custom evaluation framework to measure AI system conformance to a clinical safety constitution, tracking hallucination rates, false positives/negatives, and safety metrics
Built a human-in-the-loop verification system allowing clinicians to validate AI-generated answers, which were then marked as verified for future patients asking similar questions
Skills: RAG (Retrieval Augmented Generation)EvalsClaude Code Cursor AI
Led technology strategy and engineering for a FinTech startup building financial wellness products for employees.
Built and led the engineering team, implementing a lightweight, high-touch growth management process that aligned individual development goals with work assignments—resulting in 100% retention of the technical team
Led the design and development of Wealthbit's mobile app, working with design consultancies to deliver the MVP and grow the product from concept to production: iOS & Android
Implemented a high-fidelity, component-based design system in Figma and UI library in React/Storybook, built on design tokens—reducing design decision fatigue for engineers and ensuring consistency across the platform
Adopted a custom version of 37signals' Shape Up process to balance design, research, and development in a post-agile environment
Engaged trusted design and development consultancies to augment the product team's capabilities when needed
Revamped Wealthbit's security compliance at no additional cost by implementing the open CIS (IG2) framework, enabling demonstrable compliance mapping to SOC 2 and ISO 27001 without premature certification overhead
Worked in a growing team to service three simultaneous contract research projects using Fora Health, assisting Ctrl Group's transition from services-based to a product-based business. Built and maintained the in-house backend for the flagship product, Fora Health, replacing an off-the-shelf solution. Worked in a multi-disciplinary team including the co-founder, a clinical researcher, user reseachers, iOS and Android engineers, a designer, and QA and release management.
Complete backend: mobile and web API, backoffice admin UI, independent application services, data exports, and custom anonymised user activity analyticsm
Led the integration of Fora Health with the Epic EMR medical system including implementation, end-to-end—security due diligence, Epic EMR's third-party application review, and listing on the Epic App Orchard
Achieved HIPAA compliance early on using Very Good Security's transparent PII proxy, avoiding PII storage entirely
Prototyped the first care team web application which has grown significantly since initial launch
Used a modified version of 37Signal's Shape Up process to balance the needs of research, design, and development in a fast-moving environmentd
Skills: Ruby on RailsReact.jsAmazon Web Services (AWS)PostgreSQLRedis
Technical advisory and management of the entire product lifecycle from design to implementation and management of key milestones and reporting, including developing product strategy for our clients.
Skills: Technical LeadershipProduct StrategyProduct Management People Management
Sustained and improved software development methodologies, technical guidance and leadership in software systems. Developed and maintained good client relationships, provided mentorship and guidance for juniors, and assisted in high level project strategy and estimation.
Skills: Ruby on RailsHTML, CSS, and JavaScriptAutomated Testing PostgreSQLRedisProduct Analytics
Developed a KYC workflow system in Rails to implement digital KYC in multiple legal jurisdictions for Docfox. Project duration: 18 months.
Lead the development of a Rails application and an API for iOS and Android clients that allow managers to complete checklists across hotels to maintain hotel standards for LobsterInk . Project duration: 7 months.
Developed an internal tool in Rails for Internet solutions ISP providing a consolidated view of their data services from 5 APIs including visualising usage and event data over time. Project duration: 6 months.
Technical advisory and management of the entire product lifecycle from design to implementation and management of key milestones and reporting, including developing product strategy for our clients.
Skills: Ruby on RailsGitVimtmux
University of Pretoria
Research Engineer
CIRG, University of PretoriaPart-time
Pretoria, South AfricaOn-site
CIRG (Computational Intelligence Research Group) offered the opportunity to develop algorithms for their open source CI library called CILIB. I helped implement adaptive differential evolution algorithms. See cirg.cs.up.ac.za and github.com/cilib/cilib for more information.
Concurrent Systems (COS 226). Tutoring Concurrent Systems involved giving a weekly class test and helping students understand complex concepts by discussing the memorandum and answering general questions.
Education
BSc (Hons), Computer Science (Cum Laude)
University of Pretoria
Pretoria, South Africa
Major in Computational Intelligence
Dissertation on Adaptive Architecture Selection, in which neural network architecture is a control parameter during training. The aim of the study was to dynamically find and adapt the models optimal architecture in order to prevent overfitting and to improve the network’s ability to generalise (paper available upon request).
BSc, Information & Knowledge Systems (Cum Laude)
University of Pretoria
Pretoria, South Africa
Major in IT & Music
Final year project on the development of a secure wireless access portal comparing the amount of information retrieved from active versus passive scanning in the digital fingerprinting of devices connecting to the network.
National Senior Certificate (NSC)
Willowridge High School
Pretoria, South Africa
Awards & Achievements
2015 – 2019: Global speaking engagements
Multiple speaking engagements across South Africa, USA, and UK
2018: Tech Nation endorsement
Endorsed as a global leader in the technology community
2013: Top of the class – tie
Award for the top student in BSc (Hons) Computer Science
2012: Top of the class
Award for the top student in BSc Information & Knowledge Systems
2012: Best undergraduate project
Award for the best year long project: a secure wireless access portal
2012 – 2013: Academic honorary colours
Academic certification of merit awarded to students that graduated with distinction (Cum Laude)
Crafting remarkable software products and helping teams do the same. Former CTO, from product design to production ML. Booking contracts or looking for gainful employment.
