Senior JavaScript Engineer, Full-stack, Retention

This is a fully remote position, open to applicants in Portugal.

📋 Description

• Create and enhance TypeScript services that power personalized replenishment, cross-selling, and subscription offerings for Shopify stores.

• Collaborate within an AI-driven, multidisciplinary product engineering team to deliver contemporary software for high-traffic subscription and billing systems.

• Design and implement serverless TypeScript services using AWS Lambda, supported by MySQL and Prisma ORM.

• Contribute to React applications that depend on company APIs and integrate with Shopify and Klaviyo.

• Take ownership of features throughout their lifecycle, from defining customer issues and proposing architecture to implementation, monitoring, and production management.

• Assist Customer Success by adhering to a working-hours escalation schedule and ensure the stability of the live production system.

• Engage in architectural discussions and contribute to technical decision-making within Relo and Relay Commerce.

• Incorporate agent context into codebases, manage coding agents, build MCPs, and develop AI product features for LLM integrations, like Shopify Sidekick.

• Enhance processes, guidelines, and documentation within a fully remote organization.

⛳️ Requirements

• Extensive, verified senior-level experience with JavaScript across various frameworks; at least 8 years of experience across multiple organizations.

• Profound experience in designing REST APIs, particularly for systems that integrate with third-party platforms.

• In-depth knowledge of crafting TypeScript using class-oriented design, strong typing, SOLID principles, OOP patterns, and test-driven development.

• Strong understanding of SQL and relational databases, including query performance, indexing strategies, and schema design in MySQL or another RDBMS.

• Solid proficiency in React, encompassing components, interactive UIs, application state, and backend API integration.

• Experience with cloud-native services in Amazon Web Services.

• Proven track record of owning features from conception to delivery.

• Experience in defining and launching significant features as part of a team.

• Ability to utilize AI agents like Claude Code or Codex and articulate skills, MCPs, RAG, and other AI tools.

• Exceptional written and verbal communication skills.

• Strong customer focus.

• Highly desirable: Experience with predictive algorithms.

• Highly desirable: Familiarity with the Shopify platform, its structures, and data.

• Highly desirable: Experience with SRE practices and observability tools such as DataDog.

🏝️ Benefits

• Flexible Time Off.

• Public Holidays Off.

• Paid Parental Leave.

• Work From Home Stipend.

• Therapy/Mental Health Reimbursement.

• Co-working Space Allowance.

• Company Swag.