About

Hello there! I am Jairus ‘JJ’ Joer, a Senior Full Stack Engineer and Designer based in Germany with 7+ years of experience. I care deeply about software that feels thoughtful in every layer: clear in its structure, expressive in its interface, respectful of the people who use it, and deliberate in the way it supports real work.

The work I delight in most sits at the intersection of user experience, accessibility, design systems, and developer experience. I enjoy shaping systems that make taste practical, whether through refining interfaces, building resilient foundations, or creating tools that disappear into the flow of thought.

In recent years, I have helped teams modernise platforms, improve performance, and adopt shared systems that raise the quality of everyday work. Most recently at HERO Software, I drove design system adoption, monorepo orchestration, and platform modernisation across multiple engineering teams.

Skills

Alpine.js
Astro
CakePHP
Cloudflare
Codegen
Design Systems
Docker
ESLint
Figma
Git
GitHub
GitLab
GraphQL
GSAP
Jest
MySQL
Next.js
Node.js
Nuxt
PHP
Playwright
PostgreSQL
Prettier
ProcessWire
React
Rspack
Sass
Sentry
Storybook
Style Dictionary
Tailwind CSS
Temporal
Turborepo
TypeScript
Vitest
Vue.js
WCAG 2.1
Webflow
webpack

Experience

Senior Full Stack Engineer at HERO Software
Hanover, Germany · Hybrid
Apr 2024 — Mar 2026
- Led cross-departmental initiatives, shipping code and design standards company-wide
- Modernized frontend platform via Rspack, cutting build times 50%+ and cold start 41%+
- Established design system driving products consistency across 5 teams and 35+ people
Freelance Developer and Designer
Hanover, Germany · Hybrid, Part-time
Nov 2020 — Present
- Built high-performance web solutions for SMEs meeting modern accessibility standards
- Optimized conversion flows translating goals into measurable engagement improvements
- Sustained repeat and referral pipeline via ongoing technical advisory and reliability
Full Stack Developer at neuwaerts
Hanover, Germany · Hybrid
Jul 2019 — Mar 2024
- Increased organic traffic 120% and conversion 33% for a diving travel platform
- Trained 50+ employees through workshops, establishing design system practices
Media Designer Apprentice at TA Bildungszentrum
Hamelin, Germany · On-site
Aug 2018 — May 2019
Co-Founder at XVI CHAPEL
New York, United States · Remote
Apr 2016 — May 2017
- Co-founded digital creative agency delivering brand identities for content creators
- Executed strategic exit post validation to pursue engineering and product opportunities
Marketing Manager at World Of Bass Records
New York, United States · Remote, Part-time
Oct 2015 — Aug 2016
- Managed digital presence and campaigns crafting strategy for content creators
- Applied data-informed experimentation to improve engagement and marketing skills

Awards

BCM Content Platforms B2C Gold
For zukunftswaende.de, at neuwaerts
Jan 2022

Projects

Co-Author and Maintainer at Aggregata
Technical blog reaching 9,000+ monthly unique visitors
Aug 2022 — Dec 2025
- Published 39 articles on web architecture, accessibility, and emerging tooling
- Scaled to 9,000+ monthly readers via consistent publishing and SEO strategies
- Built credibility and inbound opportunities through actionable, focused writing

Speaking

Figma Workshop Series
neuwaerts · Multi-part training for design and project teams
Nov 2023
Working with Projects and Files
neuwaerts · Multi-session workshop for an enterprise client
Sep 2023
Digital Tools for Clients
neuwaerts · Seminar on AI-enabled collaborative workflows
Jul 2023
Generative Texts
neuwaerts · Technical overview of emerging AI text generation
May 2023
New Work
neuwaerts · Cloud collaboration tools and GDPR compliance
Nov 2019

Education

Media Design Apprenticeship
Multi Media Berufsbildende Schulen Hannover (MMBbS)
Aug 2018 — Jul 2021
- Received laudatory recognition for scoring 95/100 points across the curriculum
Matura in Linguistics
Kooperative Gesamtschule Gronau (Leine)
Sep 2015 — Jun 2018