Senior C# Backend Engineer

About us: We build a cloud-based POS platform used by hospitality businesses every day. Our products handle real-time orders, payments, inventory, and AI-powered features. We're looking for a Senior C# / .NET Engineer to own the backend services at the core of the platform and help us build the next generation of hospitality software. About the position: TThe ideal candidate is an experienced backend engineer who is comfortable owning a service end to end - from the data model and API contract, to the message flow, to shipping it and keeping it healthy in production. You should be able to have a real conversation with product and other engineers about trade-offs, and pragmatic enough to know which correctness problems must be solved before anything else. Our .NET services handle money, fiscal receipts (Croatian CIS/FINA fiscalization), and inventory, so much of the work demands accuracy over speed - care with correctness, idempotency, edge cases, and regulatory constraints matters more than raw throughput. A miscalculated tax line or a receipt that never reaches the tax authority is a real problem, not a warning in a log. You will own the parts of the system where getting it exactly right is the job. Main responsibilities: Design, build, and own backend services in C# / .NET (ordering, fiscalization, payments) - from data model to API to production behaviour.Model correctness-critical domains carefully: tax breakdowns, fiscalization, storno/void flows, discounts, and the invariants that must always hold.Work with PostgreSQL day to day - schema design, migrations that stay safe against live data, query performance, and the constraints/triggers that protect the data.Build and reason about asynchronous, event-driven flows: SQS FIFO queues, message consumers, retries, dead-letter handling, and idempotent processing.Integrate with external systems (fiscalization/CIS, payment providers) and handle their failure modes deterministically rather than hoping they succeed.Write clear tests and make the correctness guarantees explicit, especially around money and fiscal documents.Own operational health of your services: meaningful errors, sensible alerts, and the ability to explain what a service did after the fact.Collaborate with product, Android, web, and QA to take features from specification to release.Keep regulatory and fiscal requirements in scope from the start, not as an afterthought. Qualifications: Minimum of 5 years of professional backend development experience, including ownership of a service or a significant backend area.Strong C# / .NET (ASP.NET Core) skills, with production experience running real services.Solid PostgreSQL: you can design a schema, write and read non-trivial SQL, and reason about constraints, transactions, and migrations against live data.Experience with asynchronous and message-driven architectures (queues, consumers, retries, idempotency).A correctness-first mindset: you think about edge cases, failure modes, and invariants before you think about how fast it runs.Comfortable owning the outcome in a small team, not just closing a ticket.Proficient in written and spoken English.Available for regular collaboration during CET business hours. Nice to have: Experience with fiscalization, accounting, payments, or other correctness-critical and regulated domains.Experience with Hasura / GraphQL and event-trigger driven data flows.Experience with AWS (SQS, RDS, EKS) and running services on Kubernetes.Experience integrating card-payment terminals or e-invoicing providers.Background in hospitality, POS, retail, fintech, or payments.Experience shipping AI-powered product features. What we offer: Remote work modelFlexible work timeModern development stackHigh autonomyNo unnecessary meetingsFast decision makingSmall team with real ownership and direct impact on product decisionsAdditional benefits to support your professional growth and well-being Hiring Process: Initial Conversation with HR – We'll begin with a brief conversation to get to know you better, discuss your experience, and see whether the role is a good fit for both you and our team.Product Interview – During the interview, you'll be given a practical product case. We'll discuss your approach, evaluate your reasoning, and dive deeper into how you prioritize, specify, and ship. Application process:We'd love to hear from you. Send us your CV or LinkedIn profile to info@ekonobar.hr and let's talk. eKonobar is an equal opportunity employer. We support diversity and are committed to creating an inclusive environment for all employees. We do not discriminate on the basis of race, religion, creed, color, national origin, sex, pregnancy, sexual orientation, gender identity, gender expression, age, ancestry, physical or mental disability, medical condition, including medical characteristics, genetic information, marital status, military service, or any other classification protected by applicable local or state laws. All hiring decisions are based on business needs, job requirements, merit, and individual qualifications.