Backend Engineer (Platform)

SUNOLLO PTE. LTD.; Singapore; On-site; SGD 80,000 - 120,000; Full time

Job summary

A premium energy solutions company in Singapore is seeking a Backend Engineer (Platform) to design and implement critical backend systems. This senior role focuses on building a billing platform and requires strong backend engineering fundamentals, experience with PostgreSQL, and the ability to work independently. Candidates should have a degree in Computer Science or a related field with at least 5 years of experience. Join us in making clean energy simple for homes as part of a fast-growing team.

Qualifications

• 5+ years of backend engineering experience preferred.
• Experience shipping production systems required.
• Understanding of monitoring and failure handling is essential.

Responsibilities

• Design and implement backend systems that are revenue-critical.
• Build a billing and invoicing engine.
• Ensure system reliability through logging and monitoring.
• Collaborate with product, finance, and operations teams.

Skills

Strong backend engineering fundamentals

Experience with PostgreSQL

Experience building API integrations

Understanding of system reliability

Ability to work independently

Education

Degree in Computer Science, Engineering, or related field

Tools

PostgreSQL

OAuth2

Job description

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 Responsibilities

• 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 OAuth2, 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 Requirements

Must Have

• Strong backend engineering fundamentals with experience shipping production systems
• Experience with PostgreSQL and practical database design
• Experience building and operating API integrations (OAuth2, webhooks, retries, idempotency)
• Strong understanding of system reliability, monitoring, and failure handling
• Ability to work independently with high ownership and minimal supervision

Good to Have

• Experience with billing systems, subscriptions, invoicing, or payments
• Experience integrating accounting or CRM systems (e.g. Xero, HubSpot, Salesforce)
• Experience with Supabase or managed Postgres / serverless environments
• Experience building internal tools or admin dashboards
• Startup or fast-growth company experience

Qualifications

• Degree in Computer Science, Engineering, or related field (or equivalent practical experience)
• Senior level preferred (5+ years of backend engineering experience); strong mid-level candidates may be considered