Senior Kotlin Backend Developers

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