Senior Software Engineer

Extend

Senior Software Engineer II at Extend building impactful software for ECommerce and Brick and Mortar merchants. Collaborating with cross-functional teams to drive innovation and customer satisfaction.

Posted 5/29/2026full-timeRemote • California • 🇺🇸 United StatesSenior💰 $171,000 - $198,000 per yearWebsite

Tech Stack

Tools & technologies

CloudJavaScriptNode.jsReactTypeScript

About the role

Key responsibilities & impact

Tackle ambiguous, cross-system problems spanning all aspects of fulfillment and servicing
Own large features end to end, from design through deployment, release, and monitoring
Deliver scalable, event-driven, AI-native applications that elevate the customer experience
Collaborate with platform teams to enhance overall system architecture
Own the design, implementation, quality and safety of AI/agentic features in production systems
Mentor other engineers across levels through code review, pairing, design collaboration and coaching
Drive adoption of tooling and practices, including AI developer tooling, and codify the habits that make them effective
Advocate for the proactive investments — refactors, observability, upgrades, technology adoption - that enable continuous improvement
Communicate fluently across product, design, solutions, and ops to align outcomes with business goals

Requirements

What you’ll need

8+ years of full-stack experience
Proven track record building distributed, cloud-native applications, with hands-on serverless experience
Demonstrated experience shipping AI/LLM features to production
Strong instincts for API design and backwards compatibility — especially where events drive money movement or fulfillment
A track record of owning large, ambiguous, cross-system initiatives end to end
Proven ability to influence beyond your team — aligning groups, distilling complex ideas for leadership, and pushing back with data
A pattern of mentoring across levels and driving team-wide improvements that outlast any single project
Strong data modeling and context engineering skills that ensure application quality and sound agentic decisioning
Fluency with advanced AI developer tooling, a track record of using it to ship more, and a habit of bringing teammates along
Exceptional communication across product, business stakeholders, designers, support, and engineers
Expert in TypeScript, Node.js, and React.

Benefits

Comp & perks

Competitive salary based on experience, with full medical and dental & vision benefits.
Stock in an early-stage startup growing quickly.
Generous, flexible paid time off policy.
401(k) with Financial Guidance from Morgan Stanley.

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills & Tools

full-stack developmentcloud-native applicationsserverless architectureAI featuresAPI designdata modelingcontext engineeringTypeScriptNode.jsReact

Soft Skills

mentoringcommunicationinfluencingcollaborationproblem-solvingcoachingalignmentdistilling complex ideasdriving improvementsadvocacy