Senior Software Engineer, API Platform

The MNTN API Squad owns the APIs to serve both external partners and internal teams, acting as the core contract behind all MNTN UIs and integrations. The squad builds and operates scalable, reliable APIs—allowing customers to operationalize advertising directly through code.

If you enjoy building platform APIs that enable scale, automation, and deep product integration, this role may be a great fit.

What you’ll do:

• Be part of a team that focuses on our next-generation API platform.
• Architect and evolve large-scale backend systems, foundational platform services, and API ecosystems that enable backend and frontend teams to move faster with consistency and reliability. Familiar with API-first design, concepts such as Atomic API design.
• Define and refine domain models, service boundaries, and system interactions using domain-driven design (DDD) principles.
• Participate in technical discussions across engineering teams, driving alignment on architecture, standards, documentation, and long-term platform strategy.
• Design and drive implementation of scalable, observable, and fault-tolerant services—including caching, messaging, data pipelines, and service orchestration.
• Expert in Observability-first development.
• Partner with backend and frontend teams to ensure APIs and platform capabilities strongly support user experience and frontend architecture patterns (including MFE).
• Conduct deep-dive technical investigations, performance tuning, and root-cause analysis for complex systems in production.
• Establish best practices for testing, release engineering, and operational excellence across the engineering organization.
• Champion platform security, reliability, scalability, and long-term maintainability in every stage of the development lifecycle.

What you’ll bring:

• 5+ years building and scaling backend systems, distributed architectures, and API-driven platforms, with a strong record of delivering reliable, adaptable services.
• Apply strict enforcement of best practices and ensure adherence to public API standards, such as OpenAPI.
• Deep expertise in API strategy and design (REST, GraphQL, event-driven), including versioning, governance, and lifecycle management across domains.
• Hands-on experience with modern backend languages (Node.js, TypeScript) and the ability to guide teams on best practices and technology choices.
• Strong proficiency with relational databases—especially PostgreSQL—covering schema design, indexing, performance tuning, and data modeling.
• Solid understanding of cloud-native architectures (GCP preferred), IaC tools, security principles, identity/auth, and production observability.
• Comfort with development environments, scripting, debugging, and performance tuning, with a focus on automation and improving developer workflows.
• Strong knowledge of CI/CD, automated testing, Git workflows, and release processes to ensure reliable, high-quality deployments.
• Experience collaborating with UI/UX and frontend teams, with awareness of how API and domain design shape client architecture (including MFEs).
• Excellent communication skills, able to translate complex architectural concepts into clear guidance for both technical and non-technical stakeholders.