Software Engineer II - Fulfillments Team

Extend

8d•$140,000 - $160,000

About The Position

Extend is seeking a Software Engineer II to join the Fulfillments team, which builds software supporting customer satisfaction and company growth. The role involves developing software used by large e-commerce and brick-and-mortar merchants to support their customers. The engineer will collaborate with product, design, operations, delivery, and engineering teams, contributing to innovation and continuous improvement. The position focuses on building fulfillment and servicing features, including refunds, replacements, and reverse logistics. The engineer will own features end to end, develop scalable event-driven and AI-native applications, build single-page applications, and contribute to system design, production monitoring, and proactive technical improvements. The role also involves building and monitoring AI features in production and using AI developer tools in daily work.

Requirements

At least 4 years of full-stack experience.
Hands-on experience building production systems on AWS, including serverless systems.
Demonstrated experience shipping AI/LLM features to production.
Solid understanding of API design, versioning, idempotency, and backwards compatibility, particularly where events drive money movement or fulfillment.
Track record of owning features end to end and handling ambiguous problems with limited direction.
Experience building production single-page applications with modern state management and collaborating closely with designers to turn UX into quality software.
Sound data modeling skills and a working understanding of context engineering for agentic features.
Daily fluency with AI developer tooling and willingness to share effective practices with teammates.
Willingness to raise concerns early and push back with data.
Clear communication with product teams, business stakeholders, designers, support, and engineers.
Ability to form clear opinions and advocate for them.

Responsibilities

Build and ship features across fulfillment and servicing, including refunds, replacements, and reverse logistics.
Take on ambiguous problems with growing independence.
Own features end to end, from design and development through deployment, release, and monitoring.
Deliver scalable, event-driven, AI-native applications that improve the customer experience.
Build single-page applications and partner with design on user experience, including client and server state management.
Work with senior engineers and platform teams on system design, raising risks and tradeoffs early.
Build, test, and monitor AI and agentic features in production, with attention to quality and safety.
Use AI developer tooling daily and share effective practices with the team.
Identify and deliver proactive investments such as refactors, observability improvements, and upgrades in areas owned.
Communicate with product, design, solutions, and other engineering teams to align work with business goals.