Principal Engineer, API & MCP Platform

Role Summary

We are seeking aPrincipal Engineer to lead Babel Street's API and MCP platform strategy and deliveryas we evolve toward anAI-native, agent-driven platform.

This is ahands-on, senior technical leadership roleresponsible for defining and deliveringAPI-first platform capabilitiesthat enable both developers and AI agents to interact with Babel Street's services. You will lead the design and implementation ofsemantic APIs, Model Context Protocol (MCP) integrations, and context-aware service patternsthat power next-generation intelligence workflows.

This role requires afinger-on-keyboard engineerwho can both define direction and deliver foundational systems. You will partner closely with AI, Data, and Platform teams to ensure Babel Street's APIs and services areconsistent, discoverable, scalable, and optimized for agentic workflows.

You will work in close partnership with the Architecture function to align on long-term technical direction, ensuring API and MCP platform decisions are consistent with the company's broader architectural vision whilemaintaininga strong focus on execution and delivery.

This is a hybrid role working out of either our Reston, VA or Somerville, MA office. Full remote may be considered.

Why This Role Matters

This role will be instrumentaltoBabel Street's AI-native technology strategy. The API and MCP platform will serve as the interface layer between data, AI, and product capabilities, enabling agents, developers, and systems to interact seamlessly.

This is a high-impact, senior technical leadership role with broad influence across the organization and the opportunity to shape the future of Babel Street's platform. The position spans four core domains:

API Platform & Strategy

You will define and lead Babel Street'sAPI-first platform strategy,establishingconsistent patterns for service design, versioning, discoverability, and governance.

You will help evolve the platform towardagent-ready APIs, ensuring services are consumable by both human developers and AI agents. You willestablishstandards for API consistency, reliability, and performance across the organization.

You will also work closely with product and engineering teams to ensure APIs are designed asfirst-class platform capabilities, not just service interfaces.

MCP & Agent Integration

You will lead Babel Street'sModel Context Protocol (MCP)strategy and implementation, enabling agents and AI systems to interact with services in a standardized and scalable way.This includes defining patterns for:

• MCP service exposure
• Tool and service discovery
• Agent-to-service communication
• Context-aware interactions

You will partner closely with AI and platform teams to enableagent-native workflowsacross the organization.

Semantic APIs & Agent-Ready Interfaces

You will lead the design ofsemantic, agent-friendly APIs, where documentation becomes a first-class interface for AI-driven systems.This includes defining standards for:

• API descriptionsoptimizedfor agents
• Schema consistency and semantic modeling
• Tool and service discoverability
• API documentation optimized for agent consumption

You willestablishbest practices fordocumentation-as-code, ensuring APIs are designed for both developers and AI systems.

Context Management & Runtime Patterns

You will define patterns forcontext-aware APIs and services, including:

• Context management and retrieval
• Context caching
• Session and state management
• Memory-aware service interactions

You will help design scalable context-aware systemsleveragingtechnologies such asVertex AI Context Cachingand related frameworks.

Key Responsibilities

• Partner closely with Architecture to define and lead Babel Street's API and MCP platform strategy
• Design and deliver semantic, agent-ready APIs
• Establish MCP standards and implementation patterns
• Define context management patterns for agent workflows
• Partner with AI and Data teams to enable agent-native architectures
• Establish API governance and platform standards
• Build foundational frameworks and reusable components
• Provide hands-on technical leadership and mentorship
• Partner with Google and other vendors on platform capabilities
• Drive adoption of API and MCP standards across engineering teams

Required Qualifications

• 10 years of software engineering experience
• Experience operating at Principal Engineer or Staff level
• Strong hands-on experience building distributed systems
• Experience designing and building API-first platforms
• Experience with cloud-native architectures (GCP preferred)
• Experience building developer platforms or service-oriented architectures
• Strong system design and architectural thinking skills
• Proven ability to lead cross-team technical initiatives

Preferred Qualifications

• Hands-on work with Google Cloud Platform (GCP)
• Familiarity with Vertex AI Agent Engine
• Background in ADK and reasoning frameworks such as LangChain
• Understanding of the Model Context Protocol (MCP)
• Exposure to data warehouse technologies like BigQuery and Snowflake
• Knowledge of Apigee or similar API gateway solutions
• Proven ability to design semantic APIs for AI or agent-driven use cases
• Experience managing context or building memory systems
• Development of agent-based architectures or orchestration frameworks
• Exposure to Anti-Gravity

What Success Looks Like

30 Days

• Assess current API and platform architecture
• Define API and MCP platform strategy
• Identify early opportunities for standardization

60 Days

• Deliver initial platform frameworks and standards
• Begin rollout of semantic API patterns
• Establish MCP integration approach

90 Days

• Agent-ready APIs in production
• MCP-enabled services deployed
• Clear platform standards adopted across teams
• Measurable improvement in API consistency and developer velocity

Benefits at Babel Street (just to name a few...)

• Health Benefits: Babel Street covers 85-100% monthly premium costs for Medical, Dental, Vision, Life & Disability insurances - for you and your family!
• Retirement Plans:Babel Street offers both a Traditional and Roth 401(K) with a very competitive match.
• Unlimited Flexible Leave: We trust our employees to manage their own time and balance their personal and work lives.
• Holidays: Babel Street provides employees with 12 paid Federal Holidays
• Tuition Reimbursement: We are committed to investing in our employees. One way we do that is with our Tuition Reimbursement Program for continuing education.

Babel Street is anequalopportunity/affirmative actionemployer. All qualified applicants will receive consideration foremploymentwithout regard to sex, gender identity, sexual orientation, race, color, religion, national origin, disability, protected Veteran status, age, or any other characteristic protected by law. Further,Babel Street will not discriminate against applicants for inquiring about, discussing or disclosing their pay or, in certain circumstances, the pay of their co-worker,Pay Transparency Nondiscrimination.In addition, Babel Street's policy is to provide reasonable accommodation to qualified employees who have protected disabilities to the extent required by applicable laws, regulations and ordinances where a particular employee works. Upon request, we will provide you with more information about such accommodations.