Retail & automotive trade
06
Accounting OS
GoBD-compliant accounting & warehouse system
HD Autoservice01/2024 – 12/2024 · ~12 months · ongoing maintenance · Sole developer · full-stack & AI
Role
Sole developer · full-stack & AI
Team
Solo · client project
Location
Salzgitter, DE · remote
Visibility
Internal system
Responsibilities
- Accounting module: invoices, corrective invoices, PDF export, customer management, order import with GoBD-compliant record locking.
- Coupling of warehouse management and invoicing (automatic stock deduction, minimum-stock notifications).
- A resilient data synchronisation service (“pipe service”) for supplier catalogues — up to 20 m CSV rows over TLS with a queue, caching, retry logic, validation and deduplication.
- Role-based access control (better-auth); type-safe GraphQL and REST interfaces (NestJS, MikroORM, DTOs).
- Sole responsibility for the architecture (clean architecture), deployment and ongoing maintenance.
Outcome
- According to the client, up to 40 hours less administrative work per month — roughly 480 hours a year, or about € 19,200 at an assumed labour cost of € 40 per hour.
- According to the client, routine processes take up to 50 % less time.
- End-to-end digital, GoBD-compliant workflows with warehouse and accounting directly coupled.
Testimonial
Technologies
TypeScriptNode.jsNestJSNext.jsReactFastifyREST APIGraphQLDTOsType safetyData synchronisationCSV processingMessage QueuesCachingMariaDBPostgreSQLRedisMikroORMTanStack QueryTailwind CSSInventory managementWarehouse managementAccountingERPGoBDbetter-authJWTRole-Based Access Control (RBAC)DockerSelf-HostingLinuxUbuntuCI/CDGitHubGitHub ActionsClaude CodeCursor AIModel Context Protocol (MCP)MicroservicesClean Architecture