Senior Kotlin Backend Developers

Job description

Project Details

Project: Greenfield Accounting Engine

Start: Mid/late October, latest early November 2026

Duration: 6 months with option for extension

Workload: 120–160 hours/month

Location: Remote / Nearshore

Time Zone: Maximum ±1 hour from Germany

Language: English

Team: 5 Backend Developers + 1 Engineering Manager

The project is particularly suitable for experienced backend engineers who are comfortable working in a modern, architecture-driven environment with a strong focus on engineering quality, scalability and structured software delivery.

Developer focus: Kotlin + Spring Boot/WebFlux + AWS + Event Sourcing + DDD + TDD, with very strong software quality standards.

The client is building a new Accounting Engine that will become the central accounting platform for new markets. The solution will process business events such as invoices, receipts and transactions, generate accounting entries, and support reporting and further data-driven analytics.

Must-have

Backend:

- Kotlin

- Spring Boot

- Spring Boot WebFlux

- AWS

- PostgreSQL

- AWS Aurora PostgreSQL

Architecture:

- Event Sourcing

- Domain-Driven Design (DDD)

- Modern backend architecture

- Hexagonal Architecture

Quality:

- TDD

- Test-driven development

- High test coverage

- Strong software quality standards

- Quality gates

🟡 Should-have

- jOOQ

- Flyway

- Hexagonal Architecture

- Greenfield projects

- GitHub

- GitHub-based CI/CD

- SonarCloud

- Experience working with Product Owners

- Delivery-driven development

🟢 Nice-to-have

- AI Engineering

- AI-assisted development

- AI Delegated Engineering

- Claude / Cursor

- Basic accounting knowledge