We are looking for a Senior Software Engineer / System Architect to take ownership of backend Python/Django projects. The role focuses on implementing and maintaining e-commerce APIs, creating partner-facing mock/test endpoints and test cases, supporting operations to help stakeholders track user/order status and ongoing maintenance and feature development of a Django-based loan transaction system project.
Responsibilities
E-commerce API server
- Design, implement, and maintain a Python/Django backend service that brokers requests between:
- External partner APIs and
- Internal kernel APIs/services
- Implement and maintain customized encryption / secure payload exchange mechanisms.
- Create and maintain mock services and test cases for external parties to support integration testing (mock responses, sandbox behavior, error simulation, replay scenarios).
- Define and maintain API contracts: request/response schemas, error codes, idempotency behavior, retry policies, and versioning.
- Inspect API usage and traces to help internal teams track current user/order status and to perform root-cause analysis of integration issues.
- Collaborate with internal teams and external partners on integration timelines, certification, and incident resolution.
- Ensure code quality through reviews, automated tests, CI/CD practices, and secure coding standards.
Loan transaction system
- Maintain and continuously develop new features for a Django-based loan transaction record system.
- Own the overall architecture across systems: data flow, integration patterns, scalability, resilience, performance tuning, security, and maintainability.
- Inspect database record and traces to help internal teams resolve the loan status and to perform root-cause analysis of integration issues.
- Implement accrual-based data logic, ensuring correctness across lifecycle events
- Optimize database schema, queries, and indexing for correctness and performance
Qualifications
- 5+ years of backend engineering experience (or equivalent), with strong ownership mindset.
- Strong proficiency in Python and Django.
- Solid experience building and integrating RESTful APIs (design, implementation, and consumption).
- Experience creating mocks/sandboxes and integration test harnesses for external partners.
- Strong debugging skills: ability to analyze logs, reproduce issues, and communicate status clearly.
- Strong relational database skills, especially MySQL , including:
- Schema design for transactional systems
- Indexing and query optimization
- Data migrations and safe change management
- Experience using AI agents to assist coding, debugging, test generation, documentation etc
- Good Cantonese, Mandarin, and English (spoken and written) for cross-team and external partner communication.
Preferred Qualifications (Nice to have)
- E-commerce and/or FinTech domain knowledge , including common integration patterns, payment/order flows, and industry constraints.
- Hands-on experience with security and cryptography in real-world integrations
- Experience with loan/repayment transaction systems , accounting/ledger concepts, and/or accrual-based calculations .
- Experience with Docker , Linux deployment, Nginx , and cloud environments ( AWS/GCP/Azure ).
- Familiarity with observability and production readiness (structured logging, metrics, monitoring/alerting, incident response, runbooks).
- Experience designing scalable integration services (rate limiting, backpressure, queues, eventual consistency, idempotency at scale).