Stefan Lüllmann

Full Stack Engineer

Hannover, Lower Saxony, Germany3 yrs 8 mos experience

Highly Stable

Key Highlights

Expert in building scalable, data-heavy applications.
Strong advocate for web accessibility and digital inclusion.
Proven track record in architectural migrations and performance optimization.

Stackforce AI infers this person is a Full-Stack Engineer specializing in SaaS and E-Commerce solutions.

Contact

Skills

Core Skills

Full-stack DevelopmentSolution ArchitectureDevopsWeb AccessibilityData Privacy

Other Skills

Next.jsTypeScriptPostgreSQLPrismaZodDockerCI/CDSEOZustandNextAuth.jsGitHub ActionsReactNode.jsWCAGGDPR

About

I believe that great Software lives at the intersection of Data Integrity (Backend) and User Experience (Frontend). As a Full-Stack Engineer, I specialize in building complex, data-heavy, scalable and easily maintainable applications using the modern React Ecosystem. My focus isn't just shipping features, but on shipping performant, type-safe architectures that don't crumble as they scale. What I am about: • Architectural Maturity: I prioritize intuitive solutions over complex hacks. I advocate for better DX as well as moving logic closer to the data itself (Thin Controllers). • Public Educator: I actively write technical Playbooks (The Senior Guide) both on LinkedIn and on my personal website, breaking down complex topics such as Prisma Performance, Zod Validation and HTTP Caching for the developer community. • Full-Cycle Ownership: From Schema Design (ER Diagrams) to Deployment (Docker/Vercel) and Accessibility compliance (BFSG 2025). My Tech Stack: • Frontend & UI: TypeScript, React, Next.js, TailwindCSS • Backend & Data: Node.js, PostgreSQL, Prisma, Redis, Zod • Auth & Security: NextAuth.js, Middleware Logic • DevOps & Tools: Docker, Vercel, Netlify, CI/CD, Git I am open for opportunities. If you are building high-impact Software or if you are scaling existing systems, let's connect!

Experience

3 yrs 8 mos

Total Experience

3 yrs 8 mos

Average Tenure

3 yrs 8 mos

Current Experience

Independent consultant

Full-Stack Software Engineer

Sep 2022 – Present · 3 yrs 8 mos · Hanover, Lower Saxony, Germany · Hybrid

Operating as a Lead Full-Stack Engineer for 15+ SME clients and Enterprise partners (NDA), delivering end-to-end Web Applications and complex system architectures.
I specialize in designing scalable solutions as well as migrating legacy infrastructure (PHP/CMS) into high-performance modern stacks (Next.js/TypeScript), reducing technical debt and improving Core Web Vitals.
Key Engineering Achievements:
Architectural Migration: Led the strategic migration of legacy client systems to headless Next.js architectures, resulting in a 60% average reduction in page load times and improved SEO rankings.
Complex Product Engineering: Architected data-heavy internal tools, including a Field Service PWA for contractor management and a Financial Calculation Engine for Utility Billing. Utilized PostgreSQL, Prisma and Zod to handle complex nested validations and real-time state management.
E-Commerce Systems: Developed a high-performance Motorsport E-Commerce Platform (NDA) featuring Optimistic UI updates, unified persistent Cart & Wishlist state management with Zustand, secure customer authentication flows and complex API integrations. Also developed "Entro" (Open Source), a computer store reference implementation featuring a switchable "Demo-Mode" abstraction layer for database-free previewing.
DevOps & Automation: Implemented CI/CD pipelines (GitHub Actions) and containerization (Docker) to automate testing and deployment, reducing release friction for client teams.
White-Label Development: Delivered robust, white-label component libraries for agency partners under strict NDA requirements, translating Figma design systems into reusable, accessible components (BFSG 2025).

Next.jsTypeScriptPostgreSQLPrismaZodDocker+3

Various ngos

Web Engineer & Consultant (International)

Jul 2020 – Aug 2022 · 2 yrs 1 mo · Istanbul, Türkiye · Hybrid

Spent two years working directly with international NGOs to build and fix their digital infrastructure. Updated their outdated static sites to dynamic, type-safe Applications using the modern JavaScript Ecosystem.
Key Focus Areas:
Built Custom Web Platforms: Developed scalable Web Apps using React, TypeScript and Node.js. This increased performance, made maintenance easier for their internal team and increased visitor numbers by an average of 30%.
Accessibility First: Ensured strict WCAG 2.1 compliance for all projects. Since these were NGOs, digital inclusion was a requirement, not an afterthought.
Privacy & Compliance: Implemented GDPR-compliant data flows and cookie logic across different legal jurisdictions (Turkey/EU).
Bridging the Gap: Acted as the technical lead for non-technical stakeholders, translating their requirements into working Software.

ReactTypeScriptNode.jsWCAGGDPRFull-Stack Development+1