About Liquid Barcodes Liquid Barcodes is a Saa S platform helping convenience and foodservice retailers build branded apps, loyalty programs, and subscription programs that drive customer engagement. We are looking for a strong backend developer with around 5+ years of experience who wants more ownership, more technical influence, and room to grow within a fast-scaling Saa S company.
The role
This is a backend role with real impact. You will help design, build, and improve product features used by leading retail brands, working closely with Product, Engineering, Customer Success, and Support. You will not just implement tickets. You will help make technical decisions, improve architecture, solve complex problems, and ensure our platform remains scalable, reliable, and easy to evolve. The role works 12:00–20:00 CET , creating useful overlap with colleagues and customers in different time zones.
What you will work on Building and owning backend features for retail customers Contributing to architecture, technical standards,



and long-term platform quality Solving complex technical issues and turning operational learnings into better systems Using AI-assisted development tools as part of a modern engineering workflow Collaborating with product, engineering, and customer-facing teams to deliver high-impact solutions What we are looking for 5+ years of software development experience Strong backend experience with . NET and C# Experience with REST APIs, microservices, My SQL or Document DB Familiarity with Rabbit MQ, Git Hub, CI/CD, and modern Dev Ops practices AWS experience is a plus Hands-on experience with AI-assisted development tools such as Cursor, Claude Code, Codex, or similar Strong ownership, communication, collaboration, and customer mindset Strong English skills, both written and spoken How we use AI in development We are actively adopting AI-assisted development across the software development lifecycle.
We are looking for developers who already have hands-o

📌 Senior backend software engineer (Madrid)
🏢 Liquid Barcodes
📍 Madrid