Henry Steinhauer.
Software, thoughtfully built.

Backend systems, developer tooling, and a few useful things along the way. Explore the workshop when JavaScript is available, or read everything here.

01 / The workbench

Things that
actually work.

Backend systems, developer tooling, and shipped web products — built with reliability in mind.

System / 01

OAuth 2.0 Provider (Go)

OAuth 2.0 provider prototype in Go exploring token issuance and scope-based access control.

Go
Gin
OAuth2
JWT
MongoDB
Docker

Modeled users, credentials, scopes, and resource access with clear domain boundaries
ERD and sequence diagrams documenting domain relationships and request flows
Dockerized setup for reproducible local development

GitHub ↗Docs/Diagrams ↗

System / 02

AI Agent Skills

Reusable Markdown instructions for AI coding assistants, with task-specific triggers and operational guidance. Currently includes a DevOps skill for Debian/Ubuntu server management over SSH.

AI
Agent Skills
Markdown
DevOps
SSH

Task-specific instructions package domain knowledge into reusable skills for coding assistants
DevOps workflows for Debian/Ubuntu service health, nginx/SSL, Docker, and security checks
Documented change review, confirmation, backups, validation, and rollback steps

GitHub ↗DevOps on skills.sh ↗DevOps skill ↗

System / 03

CI Orchestrator (Go)

Build orchestration engine with a worker-based execution model and pluggable runner abstraction.

Go
Hexagonal Architecture
Concurrency

Worker model that claims and processes builds from a Postgres-backed queue
Streams build logs through domain events and a pluggable runner interface
Execution layer designed for isolation and deterministic testing

GitHub ↗Docs/Diagrams ↗

System / 04

Recipe App (Go)

Structured Go backend service with layered architecture and relational persistence.

GO
POSTGRESQL
DOCKER/COMPOSE
GITHUB ACTIONS

Layered architecture with handlers, services, and repositories
PostgreSQL persistence with migrations and transactional consistency
Containerized development workflow with automated CI checks

GitHub ↗

System / 05

Coverage Badge CLI

CLI tool that generates coverage badges and automates README updates for CI pipelines.

TypeScript
CLI
Jest
Coverage
CI
Automation

Generates badges from coverage JSON summaries
Updates README placeholders via deterministic template injection
CI-friendly CLI; published to npm/yarn

GitHub ↗npm ↗yarn ↗

02 / The field notebook

The engineer
behind the work.

I’m Henry Steinhauer, a backend-focused software engineer at SIXT.

I design and build backend systems and developer tooling, focusing on pragmatic system design, clear abstractions, and reliable APIs.

I enjoy turning tangled problems into things that are straightforward to understand, maintain, and use. I also share technical insights and engineering reflections on Medium.

Backend engineering.
Search, messaging, and new ideas.