Backend Engineer (Platform)

Sunollo is building a premium residential energy platform that combines high-quality hardware, reliable installation operations, and software to make clean energy simple for homes in Singapore. We are looking for a Backend Engineer (Platform) to design, build, and own revenue-critical backend systems. The initial focus of this role is to build the foundation of our billing platform, followed by broader platform and internal systems.

This role is suitable for a senior backend engineer who enjoys high ownership, clear scope, and building production systems that are reliable and maintainable. Key

Design and implement backend systems that are revenue-critical and operationally important Build a billing and invoicing engine supporting subscriptions and milestone-based payments Design clean, auditable data models and event logs with replay safety Integrate with third-party systems such as Xero using O

Auth2, APIs, and webhooks Implement secure and reliable background jobs and workflows (subscriptions, reminders, billing milestones) Ensure system reliability through logging, monitoring, alerting, and failure recovery mechanisms Build backend APIs to support internal admin tools and customer-facing applications Collaborate closely with product, finance, and operations teams to deliver correct system behaviour Write well-tested, maintainable code for critical system paths Job

Must Have Strong backend engineering fundamentals with experience shipping produc