Role Mission

We are looking for a Principal-level Backend Engineer to define and build the engineering foundations for MCP adoption across the organization.

The goal is not only to build individual MCP servers, but to establish common architecture, standards, reusable TypeScript/Node.js components, and development patterns that enable multiple product teams to build MCP-compatible integrations consistently.

This is a cross-team role combining hands-on engineering, architecture, documentation, and technical leadership.

Key Responsibilities

• Design core MCP platform capabilities, including MCP clients, servers, tool invocation patterns, and integration with existing backend services.
• Define reference architectures and engineering standards for MCP servers, tools, resources, schemas, context handling, authentication, and versioning.
• Build reusable TypeScript/Node.js libraries, templates, and starter projects that provide teams with a clear development path.
• Design shared capabilities around conversation state, agent state, context management, and orchestration.
• Define architectural guidance for choosing between MCP, A2A, traditional APIs, and service-to-service communication.
• Work across engineering teams to review designs, document best practices, mentor developers, and drive adoption of common standards.

Required Experience

• Principal / Staff level backend or platform engineering experience.
• Strong TypeScript and Node.js expertise.
• Experience designing distributed systems, APIs, SDKs, frameworks, or developer platforms.
• Strong understanding of architecture, interface design, versioning, and reusable platform components.
• Practical experience with MCP clients, servers, tools, resources, and LLM tool invocation.
• Experience leading technical initiatives across multiple engineering teams.
• A2A and broader agent orchestration experience is a strong advantage.

Key Outcomes

• Product teams can independently build MCP servers using common architecture and reusable tooling.
• MCP integrations follow consistent engineering standards rather than being designed from scratch by each team.
• Teams have clear guidance on MCP, A2A, and traditional integration patterns.
• MCP expertise and best practices can scale effectively across the engineering organization.

Team size and members level?

We work with teams of varying sizes and currently have 14 Sigma employees distributed across 8 client teams, including Mid+ and Senior-level Developers.

Who works on our side, on customer’s side? (PM, PO, Architect, etc.)

For each team, the Engineering Manager is on the client’s side, while Sigma provides a Project Coordinator and Program Manager.

How long do we work with this customer? How long the project lasts and what is the estimate period for duration, growth plans?

The customer has been partnering with us for over 3 years, and the project continues to grow steadily.

At what stage is the project? (requirements gathering, design, start of development, active dev., final stage of dev., maintenance and support)

Stage of Development + Maintenance

What development practices and approaches are used?

There are no dedicated QA specialists on the project, which enables Developers to maintain full visibility across the entire development lifecycle.

Where the system is hosted/deployed? Architecture type? Application types?

Development methodology? Releases frequency?

Scrum methodology

Describe communication channel (direct or through PM\TL; response speed, voice, chat, mail?)

Communication with the Engineering Manager and the entire team is highly transparent and frequent.

B-trips – possible, required? How often? Where?

Occasional business trips to Barcelona and other European cities are part of the collaboration.