Senior AI Systems Engineer - Multi-Agent Systems

Job Description:

Company Description:

We Dream. We Do. We Deliver.

At Merkle, a dentsu company, we power the experience economy. Whetherwe’rebuilding the next greatapp, running CRM at scale for global brands, delivering technology architectures that support millions ofusers, or providing world-class data, identity, and insights solutions,it’sall in the name of craftingexperiences that set brands apart from the competition. Backed bydentsu'slegacy of innovation andcreativity originating in Japan,we’vespent over 35 years helping brands build loyalty, drive growth, andconnect meaningfully with their audiences.

We’vebeen named a global “Leader” by top industry analyst firms in categories as wide-ranging as digitaltransformation and commerce, experience design,engineeringand technology integration, digitalmarketing, data science,CRM andloyalty, and customer data management.

Why choose Merkle?

Innovation at Our Core: As part ofdentsu’sglobal network, Merkle pushes the boundaries of customerexperience, integrating creativity, technology, and data to drive real-world impact. For over 35 years,we’vebeen innovating to meet the changing needs of our clients.

Global Reach with Local Expertise: With over16,000 employeesacross 30+ countries, and part of a70,000employees’network at dentsu, Merkle blends global insights with a deep understanding of localmarkets to deliver personalized, effective solutions.

Collaborative Culture: At Merkle, your ideas and contributions truly matter.You’lljoin a team that fostersinnovation, collaboration, and creative problem-solving. Together, we work on impactful internationalprojects, making meaningful connections every step of the way.

Role Description:

About the Role

We're looking for a full-stack engineer to build and deploy multi-agent AI systems at enterprise scale. You'll design autonomous agent networks that solve real operational challenges, working across cloud infrastructure, backend services, and AI frameworks-using Claude and modern AI tools to accelerate development.

What You'll Do

• Build Multi-Agent Systems: Design and implement agent architectures using LangChain and LangSmith to orchestrate specialized agents for complex workflows.
• Full-Stack Development: Build production backends in Node.js and craft frontends for human-agent interaction; leverage AI (Claude, Cursor) to ship faster.
• AWS Infrastructure: Deploy and scale agent services on AWS (EC2, Lambda, managed services) with hands-on deployment experience.
• Observability & Reliability: Monitor agent behavior, token efficiency, and latency using LangSmith; implement fallback logic and state management for high task completion.
• Client Collaboration: Work with clients to define agent use cases, refine architectures, and iterate on deployed systems.

What We're Looking For

• Node.js & Full-Stack: Strong backend development in Node.js/TypeScript; comfortable building or working with frontends (React/Next.js).
• AWS Fluency: Practical, hands-on experience deploying and managing production workloads on AWS.
• AI-Powered Development: Daily user of Claude, Cursor, or similar AI coding tools; comfortable building with LangChain and LangSmith.
• Agent Architecture: Experience building or working with multi-agent systems (LangGraph, AutoGen, CrewAI, or custom implementations).
• Shipping Mentality: Ability to move quickly from concept to production; strong communication with technical and non-technical stakeholders.

Nice to Have

• Experience with agent evaluation, self-correction loops, or memory architectures.
• Background in consulting or product studios shipping AI-driven features.
• Python capability for specialized AI services.

*Work visa sponsorship is not available. For local documentation (NIF, NISS), please consult Portuguese authorities.

Additional Information:

Benefits andperks:

25 vacation days

Enjoy 2additionalvolunteering days to support your passion project

Mental Health: Benefit from 3 extra wellness days on top of your vacation days and a Mental HealthFirst Aider and EmployeeAssisstanceprogram to support your well-being

Health insurance (also possible for family members)

Cutting Edge Technology & Latest IT tools

Software-house environment

Agile and Flexible working hours

Hybridworking:we combine flexibility with in-person collaboration, with an expectation of 1 day per week/ 4 days per month in the office

Digital nomad policy

Focus on career development

Full access to Dentsu Academy, our global online learning platform

Beers, foosball, and ping-pong! #workhardplayhard

Free breakfast every secondWednesdayof the month

Employee discounts

Team & Company events

Referral bonus program

*At dentsu, Diversity, Equity, and Inclusion (DEI) is central to our vision: "To be at the forefront of people-centered transformations that shape society."

We cherish the unique talents and perspectives of all individuals, welcoming applicants regardless of gender, gender identity, nationality, religion, ethnicity, cultural background, sexual orientation, age, physical or mental ability. By embracing diverse perspectives, we create meaningful change and sustainable growth for our people, clients, and society. Our hiring decisions are guided by qualifications and role-specific requirements, ensuring a workplacefreefrom discrimination and harassment.

#LI-Hybrid #LI-MERKLE

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