Agent Harness Engineer

Manus AI; Singapore; On-site; SGD 90,000 - 130,000; Full time

Benefits offered by this job

Equity & shared success

Unlimited Manus Tokens

Frontier AI projects

Job summary

Manus AI in Singapore builds core systems for the agent runtime and control layer, focusing on context, tools, execution, feedback and safety. You will own design and delivery of complex components to improve reliability on real tasks.

The role emphasizes ownership of context and memory, model orchestration, task planning and integration with MCP and tools, plus evaluation and quality feedback. You will work with product, research, infra and security to review designs and deliver high-quality

Qualifications

• 3–5 years of software engineering in production systems.
• Backend or distributed systems experience with concurrency and observability.
• Ability to lead complex systems independently.
• Proficiency in Mandarin and English for technical collaboration.

Responsibilities

• Own core components for context and memory, orchestration, planning and execution.
• Drive technical decisions, design, implementation, rollout and improvement.
• Improve agent performance via context engineering, prompts, retrieval and tooling.
• Collaborate with product, research, infra and security on design reviews and quality.
• Establish reproducible evaluations, tests and observability from real tasks.

Skills

Software engineering

Distributed systems

System design

AI in research & validation

English/Mandarin communication

Tools

MCP integration

Job description

Build core systems for the agent runtime and control layer, covering context, tools, execution, feedback and safety boundaries. Own the design and delivery of complex components to improve reliability on real tasks.

Responsibilities

• Own core components for context and memory, model and tool orchestration, task planning and execution, tools and MCP integrations, and evaluation and quality feedback.
• Define problems and success criteria when requirements and technical approaches are unclear, and independently drive technical decisions, design, implementation, rollout and ongoing improvement.
• Improve agent performance through context engineering, prompt design, retrieval, tools and architecture, evaluating task success, reliability, latency and cost.
• Build reproducible agent evaluations, regression tests and end-to-end observability, using real tasks and production failures to guide system improvements.
• Work with product, research, infrastructure and security teams on design reviews, risk identification and delivery, and improve engineering quality.

Requirements

• Strong software engineering and computer systems foundations, with 3–5 years of software engineering experience or equivalent ability, and the ability to deliver maintainable, testable production systems.
• Backend or distributed systems experience covering concurrency, task queues, persistence, idempotency, failure recovery and observability.
• Ability to own complex systems or critical components independently, exercise technical judgment, control complexity and take responsibility for delivery quality and outcomes.
• Effective use of AI for research, coding and validation while retaining independent judgment, with initiative, clear communication and dependable collaboration.
• Ability to collaborate on technical work in Mandarin and to read, write and participate in day-to-day technical communication in English.
• Deep experience in context engineering, long-term memory, retrieval and ranking, model routing, tool use, MCP, multi-agent systems or agent evaluation is preferred.
• Experience with execution isolation, least privilege, multi-tenancy, prompt-injection defenses, high-risk action approvals or auditing is preferred, as is open-source work, technical writing or equivalent proprietary engineering work.

Manus excels at various tasks in work and life, getting everything done while you rest at Manus AI.

What we offer:

• Build at the Frontier of AI Agents - Work with a fast-paced team to turn frontier AI breakthroughs into real-world impact.
• Equity & Shared success - Our share incentive plan enables employees to participate in Manus’s long-term growth and share in the value we create together.
• Unlimited Manus Tokens - Enjoy unlimited Manus tokens to experiment, build, and supercharge your productivity.