PRINCIPAL, SOFTWARE ENGINEER - WFS

Job Description Summary Principal Engineer is one of the most coveted technical IC titles at Walmart - and this role lives up to it. As a Principal Engineer on the Marketplace team within Growth Tech, you will be developing services that helps millions of sellers to onboard and do business with Walmart. You will write code, design systems, review architectures, and solve the problems that are complex. Your world-class expertise in distributed systems, API design, and platform engineering will be paired with a Al-forward mindset.

About Team Walmart’s Marketplace is the backbone of a thriving ecosystem connecting millions of third-party sellers to hundreds of millions of customers worldwide. As Principal Engineer, WFS, you will be responsible for building applications that enable the fulfilment for a Seller. You will be building application to enable sellers to engage on Walmart retail platform.

This is a high-impact role sitting at the intersection of scale, commerce, and platform engineering. You will own the technical vision and execution for a portfolio of mission-critical, cross-cutting services that enables Seller to operate through Seller Center UI and APIs. You will build and grow a world-class engineering organization capable of delivering innovation at Walmart speed.

What You’ll Do The Walmart Fulfilment Services team is essential to the Marketplace ecosystem, responsible for designing and scaling the global platform that supports the complete seller fulfilment within Walmart marketplace journey. The team develops robust global workflows, and complex multi-platform integrations connecting cloud microservices, seller portals, and AI-driven analytics. You will own Architecture, design, development and delivery of Seller journey, addressing distributed systems challenges, optimize APIs, and establish architectural standards to enable international marketplace growth.

What You’ll Bring Architecture & System Design

Lead end-to-end technical design for complex initiatives involving from API contracts, UI interfaces and data models to distributed system topologies and cross-cutting concerns.

Author and review RFCs and architecture decision records (ADRs) that become the technical canon for the platform

Hands-On Engineering

Write production-grade code and not prototypes or proof-of-concepts, test and deploy them to production

Solve complex problems considering performance, reliability and scalability

Prototype new solutions rapidly using Al-augmented development workflows and then drive them to production quality

Conduct deep-dive code reviews that raise the technical bar of the team.

Own the full software development lifecycle for your initiatives involving design, development, testing, deployment, observability

Complex Problem Solving

Solve the hardest and complex problems and enable the team while doing so

Lead technical investigations for P0/P1 incidents affecting platform services; own the root cause analysis and define permanent fixes

Challenge technical assumptions early in the design process before they become expensive production mistakes

Navigate ambiguity with confidence by breaking down underspecified problems into structured technical approaches and drive alignment across stakeholders

Platform Reliability & Operational Excellence

Design for resilience from first principles. Define and own the platform’s non-functional requirements

Instrument systems to be deeply observable and use the signals to drive continuous improvement

Build runbooks and operational playbooks that enable the broader team to operate the services confidently

Al & Innovation

This role is Al-forward by design and needs someone who actively shapes how it is used and pushes the frontier of what Al-augmented engineering looks like at scale.

Day-to-Day Al Fluency

Proficient with GitHub Copilot, Wibey, and LLM-based tooling as active, daily parts of your development workflow

Use Al to compress every phase of the engineering loop: schema design validation, code generation and review, test coverage acceleration, documentation, drafting, incident root-cause analysis, and API design feedback

Identify where Al can replace toil, then build the automation yourself

Al-Native Platform Thinking

Architect and build Al-native capabilities like intelligent API heal…