I'm a full-stack developer specialising in TypeScript, Node.js, and React, with experience building scalable APIs and web platforms used by hundreds of thousands of learners worldwide.
My background combines software engineering and education technology, which gives me a strong focus on building systems that are both technically robust and genuinely useful for the people who rely on them.
Previously, I worked as a full-stack developer on a global EdTech platform used by 700,000+ learners across 180+ countries, helping optimise the GraphQL backend for performance and reliability.
Scalable learning ecosystem used by 700k+ learners in 180+ countries.
I optimised GraphQL performance (cutting redundant queries 36 → 1), implemented API rate limiting, and automated backend testing.
Focus: backend architecture, performance, developer experience.
My Next.js + TypeScript developer portfolio.
The site achieves 100% WCAG 2.2 AA accessibility and 99–100 Lighthouse scores, with Playwright + axe-core tests and CI/CD through GitHub Actions.
Focus: accessibility, front-end architecture, developer tooling.
- Accessibility-first design
- Clear, maintainable systems
- Collaboration and knowledge sharing
- Documentation as part of engineering
- AWS architecture and distributed systems
- GraphQL performance patterns
- Accessibility testing with Playwright + axe-core
- Portfolio: https://www.karlhorning.dev
- LinkedIn: https://www.linkedin.com/in/karl-horning