Senior Go Backend Engineer (Contractor, 30–40 hrs/week, long-term)

For that, we're looking for a Senior Go Backend Engineer as an hourly contractor. You'll primarily evolve our Go services: more venues, more peak load, new integrations, tougher reliability. Where it makes sense, you'll also pitch in on the web frontend (Angular 21, TypeScript, Tailwind CSS). You'll work remotely in a small senior team directly with our Tech Lead, help shape architecture decisions, and ship in short cycles. AI tools like Claude Code are part of our everyday work. This is not a one-off task but a long-term engagement, with the goal of a permanent role in our core team. ### Tech Stack Go (Golang), Gin, OpenAPI/Swagger, MariaDB (GORM), InfluxDB, Sentry, Git & GitLab CI/CD, Docker, Linux, Angular 21 (TypeScript), Tailwind CSS, Claude Code ### Responsibilities - Design, develop, and maintain scalable backend services in Go - Design and implement performant, idiomatic REST APIs, including interfaces to internal and external systems as well as web and mobile clients - Take responsibility for transactional data: payments and credits without data loss, even at peak load - Performance and error monitoring, bug fixing, and optimization of existing services regarding performance, concurrency, and resource consumption, especially SQL queries and database interfaces - Light fullstack component: implement smaller features and adjustments in the web frontend end-to-end - Ensure code quality: code reviews, unit and integration tests, best practices, and adherence to existing guidelines - Contribute to architecture decisions and the further development of our CI/CD pipeline ### Requirements - At least three to five years of professional backend experience; strong command of Go and SQL - Solid experience with REST and API-driven applications, from API design to consuming external APIs - Awareness of transactional data and the risks of data loss or outages - Knowledge of MariaDB (GORM), InfluxDB, or comparable databases - You understand how LLMs and AI agents work in software development, ideally with first hands-on experience in Claude Code, Codex, or Cursor - You master your tools, especially for debugging and performance measurement - You write clean, tested code, work in a structured way, and communicate confidently in English or German - At least four hours of daily overlap with our core hours (CET) and reliable, self-directed communication Nice-to-have: - Production experience with Docker and Linux - Experience on the web frontend, ideally with Angular, TypeScript, and Tailwind CSS - First experience with webhooks, caching, and message queues (Kafka, RabbitMQ, Redis) ### Terms - **Engagement:** independent contractor, billed hourly via Upwork - **Rate:** €50–70 per hour (depending on experience) - **Workload:** 30–40 hours per week, reliably available - **Duration:** long-term, with the option of a permanent engagement - **Location:** fully remote; optional visits to our Düsseldorf office are welcome - **Start:** by arrangement, ideally soon ### How to Apply Keep it short and specific: 1. Two to three sentences about a Go backend you built, including load or transaction context 2. Your target hourly rate and weekly availability 3. Links to code, projects