Joeri Kaiser

Forward deployed software engineer. I work directly with users to solve operational bottlenecks and build privacy-first software.

Former bartender. Reading people, active listening, and working under pressure turned out to be engineering skills.

experience

Rama

– present

Open-source Contributor

Contributor to Rama, an organization building privacy-first Android software. I work directly from community feedback and bug reports to ship features across the app suite, focusing on offline utility, performance, and accessibility.

Cozynergy

– present

Forward Deployed Software Engineer

I build internal software by working directly with the operational teams that rely on it.

  • Mapped daily workflows directly with operations leads, replacing a company-critical Google Sheets dependency with a custom in-app tool.
  • Worked alongside customer support leads to index internal documentation and build a grounded RAG pipeline for the support chatbot.
  • Built an image-processing service that extracts field photo data to generate renovation proposals for technical advisors.
  • Currently consolidating several legacy internal tools into one unified platform based on direct user interviews.

Medelse

–

Software Engineer

Built and maintained the staffing platform connecting medical facilities with healthcare professionals across France. Started as an intern and hired full-time a year later. Developed practitioner mobile workflows in React Native, administrative portals in React, and backend matching logic in PHP Symfony backed by PostgreSQL and GraphQL.

projects

luteal

Kotlin · Go

Built after researching cycle biology with my partner and finding commercial apps filled with trackers, ads, and opaque predictions. Designed around one rule: physical observations and algorithmic estimates are never presented as the same data. French-first, offline by default, with zero telemetry and optional end-to-end encrypted sync to a custom Go backend. Available on F-Droid.

app F-Droid sync backend

eurtisan

TypeScript · launching 2026

A European-centered marketplace for creatives, artisans, and makers, built solo: TanStack Start with SSR, PostgreSQL 16, Meilisearch, Mollie payments, Sendcloud shipping, GDPR-conscious architecture, and Grafana observability.

mako

Kotlin · 200+★

Rama's privacy-first Android launcher. My contributions include multi-column layouts for wide screens, PWA pinned shortcuts, backup and restore, a recycler-view refactor, Android 17 accessibility, and French translations.

repo

pin

Rust

A zero-dependency, local-first work ledger for developers and coding agents, written in Rust. Bridges human project planning with autonomous agent tool loops without cloud dependencies. Checksum-verified binaries for Linux, macOS, and Windows.

repo

FBench

Rust

A lightweight database explorer in Rust and egui: schema browser with row estimates, a syntax-highlighted query editor with autocomplete, and CSV, JSON, and XML export for PostgreSQL and MySQL. SQLx on Tokio keeps the UI responsive while heavy queries run.

repo

Invar

Go

A terminal task manager in Go, built on Bubble Tea and Lipgloss. Create, edit, complete, and filter tasks, all keyboard-driven.

repo

Also: Jin (kchat), a T3 Chat clone built in ten days and themed after my cat, and fzf-scope, a fish history plugin.

about

I spent years behind the bar in hospitality before switching to software during the pandemic. In hospitality, you succeed by observing people, listening closely, and resolving friction quickly under pressure. Those same habits shape how I build software. I talk to the people doing the work, figure out where systems break down, and build direct solutions.

Since January 2025, I have been building internal products as a forward deployed engineer at Cozynergy, alongside contributing to privacy-first Android apps and systems tools in Rust and Go.

confident
TypeScript, React, PHP Symfony, Kotlin (Android), Go, Rust
also
Node.js, Next.js, React Native, Zig, PostgreSQL, GraphQL, Docker

contact

joeri.waldemar@gmail.com

The quickest way to reach me is email. Otherwise, find me on GitHub or LinkedIn.

Based in France, open to remote. French native, English fluent.