Edge to metal.One developer.
Markus / Codevena — Fullstack · DevOps · AI Integration based in Düsseldorf.
Design, Build, Deploy, Operate. 11 live products. End-to-end ownership — now ready for a team.
How I build.
Own hardware where it matters.
No front-end-only excuses.
11 things, shipped.
Flashbuddy
Full learning SaaS — FSRS spaced repetition, AI flashcards, gamification, Stripe.
- FSRS EngineMemory-stable spaced repetition with per-user parameters.
- AI PipelineFlashcards, quizzes, OCR and PDF import — credit-gated.
- Stripe Billing4 tiers + credit packs · idempotent webhooks.
- Self-Hosted StackCoolify on a dedicated Hetzner server · Cloudflare edge · push-to-deploy.
Capypad
Bilingual SSR code-quiz across 10 languages. pgvector HNSW dedup, hardened admin-content push API.
- Bilingual SSRDE/EN equal-quality across 10 programming languages.
- pgvector HNSWSemantic dedup at insert · 1536-dim · cosine NN · O(log n).
The toolchain.
- Next.js 13/14/15/16 · React 19 · TS
- Tailwind v4 · shadcn/ui · Radix · Motion
- Vanilla JS · HTML5 Canvas · 60 Hz fixed-step
- Three.js · Shaders · Bloom · 20k particles
- Axe 0 serious/critical · Playwright E2E
- Node.js · Express · Server Actions
- Auth.js · GitHub OAuth · Allowlist
- Prisma 6.x + PostgreSQL 16
- MongoDB · SQLite · Supabase
- WebSockets · Socket.IO · Durable Objects
- Pages · Workers · D1 · R2
- Durable Objects (stateful rooms, hibernation)
- Zero-origin for games & static-first
- Presigned PUTs · S3-compatible
- Hetzner dedicated · hardened Ubuntu
- Coolify · Docker · compose · standalone
- GitHub webhooks · blue-green deploys
- Tailscale mesh-VPN · fail2ban · auditd
- BorgBackup · GitHub Actions · Sentry
- Umami (self-hosted analytics)
- OpenAI · Real-time classify + translate
- Claude + MCP · FS · render tools
- OpenRouter · cost-/model-flexible
- Metadata enrichment pipelines
- Vitest + Testing Library · Playwright
- ESLint strict · --max-warnings=0
- TS strict · noUncheckedIndexedAccess
- Allowlist-auth · defense-in-depth
- Append-only audit log · diff compute
The long path.
How Codevena runs.
Edge to metal. And back.
Each product picks its substrate: zero-origin for games (CF Pages + Worker + D1), Next.js + Prisma + Postgres on Coolify behind Traefik (Letsencrypt) for portfolio + CMS sites, Durable Objects for stateful rooms.
Architecture diagrams are abstracted — no hostnames, ports, or versions public. Defense-in-depth via DB re-reads on every server action. Append-only audit log with diff computation.
Solo-built. Now ready for a team.
I'm retraining as a Fachinformatiker — Anwendungsentwicklung (BBQ Düsseldorf, graduating 2027) and I'm looking for a 6-month internship from October 2026. Teamwork, real codebases, real projects — that's exactly what I'm after.
Get in touchLet's talk about a team to grow in.
[email protected]Just drop me a line about the role — I reply fast. Happy to hop on a call or interview, simply say so in the mail.