Senior Backend Engineer

About Virtuos

Virtuos, established in 2004, stands as one of the largest independent video game developers globally, headquartered in Singapore with offices across Asia, Europe, and North America. Specializing in complete game development cycles and art production, Virtuos has contributed to over 1,500 titles for consoles, PC, and mobile platforms, collaborating with 23 of the top 25 global gaming companies.

Operating from its Singapore headquarters since 2018 in the One-North technology park, the company hosts skilled executives, engineers, various corporate departments, and a cutting-edge R&D center dedicated to developing innovative tools and techniques to keep its studios at the forefront of technology.

Role Overview

We are seeking a Senior Backend Engineer who will design, develop, and maintain robust backend services along with AI-powered applications. This hands-on role requires active coding, architectural input, and close collaboration with cross-functional teams to translate product needs and emerging AI capabilities into production-ready solutions.

Core Responsibilities

• Develop and uphold scalable Python services and secure RESTful APIs using FastAPI.
• Manage features from initial design through testing, deployment, and ongoing support.
• Enhance existing applications, resolve production issues, refactor codebases, and perform dependency upgrades while maintaining API compatibility.
• Design optimized database interactions, caching layers, and asynchronous processing workflows.
• Implement robust authentication, authorization mechanisms, input validation, and error handling.
• Integrate large language models (LLMs) and AI services through APIs and SDKs to create reusable interfaces for application teams.
• Create reliable API and tool interfaces for AI applications with well-defined input/output schemas and validations.
• Develop AI workflows involving prompt orchestration, structured outputs, tool invocations, and streaming responses.
• Manage service reliability aspects including context limits, rate limits, timeouts, retries, and handling provider failures.
• Evaluate changes in models and prompts against test cases to balance output quality, latency, and cost.
• Design and develop multi-agent systems and workflows to automate complex business tasks where applicable.
• Write and maintain automated tests and regression coverage for backend and AI integrations.
• Enhance logging, monitoring metrics, and tracing to diagnose issues and track service and AI performance.
• Collaborate with infrastructure teams to maintain CI/CD pipelines and containerized deployments.
• Lead code reviews, document technical decisions, and mentor junior engineers.
• Work closely with product, frontend, AI, and infrastructure teams to clarify requirements and deliver sustainable solutions.

Mandatory Qualifications

• Over 5 years of professional experience in backend development, including at least 2 years focused on AI-powered services, with proven ownership of design, deployment, and maintenance.
• Expertise in Python and FastAPI, including asynchronous programming, type annotations, Pydantic, dependency injection, and REST API design.
• Hands-on experience integrating AI APIs/SDKs, including prompt engineering, structured outputs, and managing asynchronous/streaming workflows.
• Understanding challenges specific to LLMs such as context management, hallucinations, prompt injection, rate limits, and token cost optimization.
• Experience with public cloud platforms like AWS, Azure, or GCP, including deploying and operating backend applications.
• Proficient with relational databases like PostgreSQL, including data modeling and query optimization.
• Strong knowledge of secure API design, authentication/authorization, and secrets management.
• Designing reliable backend services and API integrations, adept with concurrency control, retries, idempotency, rate limiting, and timeout strategies.
• Familiarity with testing frameworks such as pytest, version control with Git, CI/CD pipelines, and containerization using Docker.
• Strong analytical and problem-solving abilities, capable of evolving and improving existing codebases autonomously.
• Excellent communication skills in both English and Chinese for cross-team technical discussions.

Preferred Skills

• Experience with AWS tools like S3, SageMaker, DynamoDB, ECS, CloudWatch, and Secrets Manager.
• Background in frontend development using Vue or React with TypeScript or JavaScript.
• Familiarity with agent frameworks such as LangGraph, Pydantic AI, or Claude Agent SDK, including multi-agent orchestration and task delegation.
• Knowledge of retrieval-augmented generation (RAG), embeddings, and vector databases like pgvector.
• Experience deploying local or self-hosted LLMs with technologies such as vLLM, Ollama, or llama.cpp.
• Work involving multimodal AI including image, audio, or 3D generation.

Employee Benefits and Work Environment

• Opportunity to play an influential role in Virtuos headquarters shaping the company's future.
• Participation in the R&D center working with advanced gaming technologies.
• Enjoy group outings and company activities fostering team engagement.
• Comprehensive medical healthcare coverage for all employees.
• Assistance with relocation to Singapore.
• Career growth and international opportunities through Virtuos' Internal Mobility Program.
• Access to a variety of internal and external professional learning resources.

Diversity and Inclusion

Virtuos emphasizes valuing diverse perspectives and experiences, fostering an inclusive environment. The company commits to equal opportunity employment embracing various backgrounds, cultures, and ideas, united by a passion for delivering better gaming experiences together.