Principal Engineer – DevX, AI

Xsolla

Principal Engineer architecting Xsolla's agent-readable Shop Builder platform. Defining APIs and interfaces crucial for developer and AI agent interactions.

Posted 5/14/2026full-timeRemote • 🇨🇦 CanadaLeadWebsite

Tech Stack

Tools & technologies

AWSCloudGoogle Cloud PlatformJavaScriptReactTypeScript

About the role

Key responsibilities & impact

Own the technical architecture of the agent-readable Shop Builder platform: which APIs to expose, in what shape, through which surfaces (REST, SDK, MCP, CLI).
Define the interface contracts that LLMs and developers interact with — React component APIs, custom block schemas, theme tokens, data binding formats — and maintain them with the rigor of a public API.
Design and lead delivery of the MCP server that allows AI agents (Claude Code, Cursor, etc.) to build, deploy, and operate Shop Builder storefronts end-to-end without the editor in the loop.
Architect the CLI and local development environment: how developers scaffold projects, iterate locally, preview changes, and push to production.
Define the deploy, versioning, and rollback model for developer-published content — custom blocks, themes, and layouts.
Design the sandbox and preview environment system so agents and developers can iterate without touching live partner sites.
Set the documentation standard: written for LLMs and humans as first-class users, maintained from single canonical sources and published to every surface (CLI help, dev docs, MCP tool descriptions, AI context).
Lead the eval harness architecture: how the team measures whether an LLM-generated block, theme, or layout is correct before it ships.
Collaborate with Principal/Staff Engineers across payments, auth, live ops, and catalog to pull inbound capabilities into coherent developer-facing surfaces.
Serve as the technical bar-raiser for the team: define code standards, review critical implementation decisions, and mentor the Tech Lead and engineers.
Contribute to hiring and define the technical culture of the team from day one.

Requirements

What you’ll need

10+ years of professional engineering experience, with a demonstrated track record as a Staff or Principal engineer who has shaped platforms, APIs, or developer tooling used by external builders.
Deep expertise in designing and shipping public APIs and SDKs, including versioning strategy, backwards compatibility, and developer ergonomics — strong opinions about what makes an API delightful vs. painful.
Expert-level proficiency in JavaScript/TypeScript and React — the primary interface language for LLMs and developers on this platform.
Hands-on experience building CLI tooling and local developer workflows (scaffolding, hot reload, file-based config, deploy commands).
Solid understanding of the Model Context Protocol (MCP) or equivalent agentic tool-use interfaces, and practical experience building tools that AI agents can reliably invoke.
Experience building systems at global scale on cloud infrastructure (AWS or GCP), with deep knowledge of containerization, CI/CD, and infrastructure-as-code.
Ability to write and reason about LLM-friendly documentation and API surfaces: you understand that token-efficiency, predictability, and schema clarity matter as much as human readability.
Exceptional technical communication: clear RFCs and ADRs, productive architecture reviews, and the ability to explain second-order consequences to engineering and business leadership.
Comfort operating in a greenfield context — you define the structure rather than inherit it.

Benefits

Comp & perks

We are passionate about fostering a supportive environment for our team, so we prioritize the physical, mental, and emotional well-being of our employees and their families through a comprehensive Benefits Program.
This includes medical, dental, and vision, PTO, and a personalized career roadmap for each employee.
By investing in professional development through training and educational opportunities, we ensure that our team thrives both personally and professionally.
Together, we’re not just building a business; we’re cultivating a community that values creativity, collaboration, and the transformative power of play.

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Hard Skills & Tools

JavaScriptTypeScriptReactAPIsSDKsCLI toolingModel Context Protocol (MCP)AWSGCPCI/CD

Soft Skills

technical communicationmentoringcollaborationleadershipdocumentation writingproblem-solvingcritical thinkingcode standards definitionarchitectural reviewhiring contribution