Principal Backend Engineer (Golang, Microservices)

DatVietVAC Group Holdings is looking for a Principal/Expert Backend Engineer to build and operate the core backend services of our Fan Commerce Platform.

You will design high-concurrency distributed systems that support major on-sale periods and entertainment events. This role is responsible for ensuring platform scalability, transaction accuracy, data security, local data residency, and reliable delivery across the product roadmap.

I. JOB DESCRIPTION:

1. Backend Platform and High-Concurrency Systems

• Design, develop, and operate scalable core backend services for the Fan Commerce Platform.
• Build systems capable of handling sudden traffic spikes during major on-sales and live events.
• Design shared-resource management mechanisms for inventory and reservations.
• Ensure consistency, idempotency, and reliable conflict handling in distributed environments.
• Design asynchronous processing flows, messaging queues, rate limiting, backpressure, and overload-protection mechanisms.
• Conduct capacity planning and collaborate with SRE Engineers on load and performance testing.
• Identify performance bottlenecks and optimize system throughput, latency, and resource utilization.

2. Commerce and Payment Services

• Develop core commerce services covering product catalogues, inventory, reservations, orders, promotions, and fulfilment-related integrations.
• Integrate payment gateways and implement secure payment workflows.
• Process payment webhooks, refunds, cancellations, and transaction reconciliation.
• Ensure the integrity, accuracy, and traceability of financial and transactional data.
• Design mechanisms to prevent duplicate processing, overselling, inconsistent inventory, and transaction loss.
• Integrate third-party services, including payment, logistics, notification, and partner systems, through reliable APIs and integration contracts.

3. Shared Services and Event-driven Architecture

• Build shared platform services, including authentication, authorization, user profiles, and system configuration.
• Develop event-driven data pipelines for data synchronization, analytics, and service integration.
• Design clean and maintainable REST and gRPC APIs.
• Define API and event contracts between microservices.
• Ensure backward compatibility and enable individual services to scale and evolve independently.
• Design asynchronous workers and reliable event-processing mechanisms.
• Contribute to architectural decisions for distributed systems, databases, caching, and messaging.

4. Data Residency, Security, and Compliance

• Design data architecture that meets local data-residency requirements in Vietnam.
• Support the separation of compute workloads and sensitive data across the relevant infrastructure environments.
• Implement role-based access control, encryption, secrets management, and audit logging for sensitive operations.
• Apply secure coding practices and relevant OWASP principles.
• Collaborate with SRE, Security, and other teams on penetration testing and vulnerability remediation.
• Support requirements relating to personal data protection, security audits, and technical compliance.
• Contribute to anti-fraud, anti-bot, and abuse-prevention mechanisms.

5. Engineering Quality and Technical Leadership

• Build scalable microservices with complete observability across metrics, logs, and traces.
• Write and maintain unit, integration, and load tests for critical services.
• Contribute to CI/CD pipelines and Infrastructure as Code practices.
• Review code and ensure compliance with agreed architecture, coding standards, security requirements, and engineering conventions.
• Make well-reasoned technical decisions and clearly communicate architectural trade-offs.
• Establish engineering standards, reusable patterns, and development guidelines.
• Mentor engineers and provide technical direction within the team.
• Collaborate closely with Product Owners, Frontend and Mobile Engineers, SRE/DevOps Engineers, UX/UI Designers, and QC Engineers.

II. REQUIREMENTS:

Education

• Bachelor's degree in information technology, Software Engineering, Computer Science, or a related field.

Experience

• At least five years of professional experience as a Backend Engineer, Software Engineer, or in a similar backend development role.
• Proven experience designing and operating production-grade distributed systems.
• Experience building transactional systems in e-commerce, fintech, payment, ticketing, reservation, or other high-concurrency environments is highly preferred.
• Hands-on experience taking a greenfield product from initial architecture and development to production operations.
• Experience providing technical direction, conducting code reviews, or mentoring engineers.

Technical Knowledge and Skills

• Strong proficiency in Golang for developing production-grade backend services.
• Working knowledge of Python, Node.js, or TypeScript is an advantage.
• Strong understanding of distributed systems, microservices, and event-driven architecture.
• Deep knowledge of database transactions, isolation levels, distributed locking, idempotency, and consistency models.
• Strong experience designing and optimizing PostgreSQL databases at scale, including indexing, partitioning, query optimization, and replication.
• Experience with caching strategies, message queues, asynchronous processing, backpressure, load testing, and capacity planning.
• Hands-on experience with Redis and Kafka, Pub/Sub, or equivalent messaging technologies.
• Experience integrating payment gateways, processing webhooks and refunds, and implementing transaction reconciliation.
• Strong understanding of REST and gRPC API design.
• Experience with Kubernetes, Docker, and production cloud environments.
• Experience with Google Cloud or AWS.
• Understanding of application security, OWASP principles, secrets management, RBAC, audit logging, and personal data protection.
• Experience with CI/CD, Infrastructure as Code, and observability tools.

Tech Stack

• Languages: Golang, Python, Node.js, TypeScript
• Frameworks and APIs: gRPC, REST, FastAPI, NestJS, Express
• Databases: PostgreSQL, MongoDB
• Messaging and caching: Kafka, Pub/Sub, Redis
• Infrastructure: Kubernetes, GKE, Docker
• Cloud and security: Google Cloud, AWS, Cloudflare
• Tooling: GitHub Actions, Terraform, Prometheus, Grafana, Datadog

Soft Skills

• Strong analytical thinking and structured problem-solving skills.
• Ability to make technical decisions based on data, system requirements, and clearly understood trade-offs.
• Strong ownership and the ability to work effectively under fixed release deadlines.
• Ability to communicate complex technical decisions to both technical and non-technical stakeholders.
• Strong collaboration skills when working with Product, Frontend, Mobile, SRE/DevOps, and QC teams.
• Ability to provide technical leadership and mentor engineers within a small team.
• High attention to detail, particularly when working with transactional and financial data.

Language Skills

• Basic English communication skills.
• Good ability to read and understand technical documentation in English.

Why You'll Love Working Here

• Full statutory insurance, including Social Insurance, Health Insurance and Unemployment Insurance, based on 100% of the official salary and in compliance with Vietnamese labor regulations.

• Working hours: Monday to Friday, from 8:30 AM to 5:30 PM, with a one-hour lunch break.

• 14 days of annual leave.

• Company-provided working equipment, including a laptop or desktop computer.

• Employee parking area.

• Annual PMP performance bonus, subject to individual KPI achievement and the Company's business performance.

• Periodic health check-ups.

• Employee engagement programs and internal activities throughout the year.