(Staff) Software Engineer – Rental Platform (m/f/d)

## YOUR ROLE AT SIXT - You set the architectural direction for the software that runs every SIXT branch. Counter, checkout, key handover, vehicle exchange and return, plus the devices and IT services connecting them. End-to-end across the branch surface - You design at the software hardware intersection. Counter PCs, customer tablets, POS terminals, scanners, keyboxes — you model how our software speaks to physical devices in real time, and you shape the integration patterns the whole organisation will adopt - You drive system-design choices across the branch domain — event-driven flows, API contracts, state ownership, device-to-cloud protocols, the boundaries between modern services and legacy interfaces. This is hands-on architecture, not architecture-by-slide-deck - You grow the engineering practice around you — across the multiple teams that touch the branch (Checkout, Counter, Rental Platform, Turnaround, Keybox, Tablet/POS) through clean design docs, sharp technical reviews, and hands-on engagement when a problem is gnarly enough to warrant it - You spend real time at the branches. The strongest architecture is shaped where the system actually runs — with agents, with devices, and with customers ## YOUR SKILLS MATTER - Expertise You have several years building production software systems at meaningful scale — customer-facing, multi-region — with a track record of taking systems from "they work" to "they are elegant and they scale" - System design depth You can sketch the architecture of a non-trivial system and defend every choice — from API design and data modeling, through event/stream patterns and state ownership, down to the trade-offs in how services talk to each other and to the outside world - Comfort at the software hardware boundary You have shipped software that talks to physical devices — POS hardware, retail or restaurant systems, embedded clients, real-time stateful client-server protocols (MQTT, WebSockets, gRPC streaming). You know "the device is misbehaving" is part of normal operation, and you design for it - Tech-stack range You are comfortable with Backend in Go / Java / Python, event streams (Kafka), databases (Postgres / Redis), and cloud (AWS / Kubernetes). Bonus for experience integrating with legacy systems you cannot rewrite — only design around - Influence and craft You have led architectural change across multiple teams through clarity, evidence and follow-through. You write design docs people actually want to read. ## WHAT WE OFFER - Extra benefits Enjoy discounts on SIXT rent, share, ride and SIXT+, attractive vehicle leasing offers, and exclusive deals with partners for travel, tech, fashion and more - Mobility boost We support you with a monthly mobility allowance of 20 per month for even more freedom - Future security We contribute to your retirement plan and support you with capital-forming benefits to ensure you are well covered - Feel-good atmosphere Stay active with our modern SIXT gym, various leisure activities like the gaming area or the SIXT choir, and enjoy our high-quality employee restaurant - Flexibility Enjoy 30 days of vacation and a hybrid working model with flexible hours - Giving back Take one day each year to volunteer at a charitable organization dedicated to supporting children