Senior Backend Engineer (AI Agent)

Commerce; Myrtle Point (OR); Remote; USD 116,000 - 195,000; Full time

Job summary

Commerce is seeking a Senior Backend Engineer to design and orchestrate AI agents for the B2B commerce lifecycle. You will shape sub-agent architecture, tool integration, and prompt strategies while ensuring trustworthy, eval-driven quality in production.

You’ll collaborate across product and frontend teams to deliver robust conversational experiences and scalable APIs. Remote-first with regional flexibility, competitive salary, and growth opportunities.

Qualifications

• 5+ years in backend or full-stack development with hands-on AI/LLM applications.
• Bachelor’s degree in CS, EE, SW, CE, MIS or equivalent experience.
• Strong development skills in Go/Python/Ruby/PHP.
• Experience working with LLMs (Gemini, Anthropic, OpenAI, etc.) in production systems.
• Experience with LLM evaluation: building datasets, defining scorers/metrics, and using eval results to drive iteration.
• Strong understanding of prompt engineering, tool/function calling, and agent orchestration patterns.
• Deep experience designing and building APIs (gRPC, GraphQL, REST) and integrating data across systems.
• Hands-on experience building MCP servers or LLM tool integrations.
• Excellent problem-solving skills and ability to work in a fast-paced, exploratory environment.
• Preferred: Experience with agent frameworks (Google ADK, LangChain/LangGraph, Semantic Kernel, or similar) and evaluation/observability platforms (Braintrust, LangSmith, or similar).

Responsibilities

• Design, build, and iterate on AI agents in Go/Python using an orchestrator/sub-agent architecture.
• Own eval-driven development: build and maintain golden datasets, scorers, and regression suites for quality metrics.
• Develop and refine prompts, model configurations; treat prompts and model settings as versioned artifacts.
• Integrate agents with MCP servers and backend tools, defining safe tool-call contracts and guardrails.
• Instrument agents with tracing, metrics, and cost tracking; use production signals to improve quality.
• Collaborate with product designers and frontend engineers to deliver conversational experiences.
• Build proof-of-concept agents quickly, then harden them to GA quality.
• Drive architecture decisions and mentor engineers in agent engineering practices.

Skills

Backend development

Agentic AI / LLM apps

Go / Python / Ruby / PHP

LLM evaluation / datasets

Prompt engineering

APIs (REST/GraphQL/gRPC)

MCP servers integration

Tool integration & guardrails

Collaboration & communication

Mentorship & leadership

Education

Bachelor’s in CS/EE/SW/CE/MIS

Tools

Go

Python

Google ADK

LangChain

Semantic Kernel

MCP servers

Job description

Role Overview

Welcome to the Agentic Commerce Era At Commerce, our mission is to empower businesses to innovate, grow, and thrive with our open, AI-driven commerce ecosystem. As the parent company of BigCommerce, Feedonomics, and Makeswift, we connect the tools and systems that power growth, enabling businesses to unlock the full potential of their data, deliver seamless and personalized experiences across every channel, and adapt swiftly to an ever-changing market. We believe in harnessing AI responsibly to unlock new possibilities, and weâre looking for individuals who use it intentionally to solve problems, accelerate outcomes, and expand whatâs possible in their role. Our purpose is to help businesses confidently solve complex commerce challenges so they can build smarter, adapt faster, and grow on their own terms. If you want to be part of a team of bold builders, sharp thinkers, and technical trailblazers who shape the future of commerce, this is the place for you. BigCommerce is building a new team to deliver a suite of conversational AI agents spanning the B2B commerce lifecycle â Product Discovery, Pricing & Quoting, Order Automation, Fulfillment & Delivery, and Post-Sale Support. The agents are built in Go on Google ADK with Gemini, with evaluation infrastructure in Braintrust and a streaming AG-UI frontend. As a Senior Backend Engineer specializing in AI agents, you will design the agents themselves: orchestration, sub-agent architecture, tool integration, prompt engineering, and â critically â the evaluation discipline that determines whether these agents are trustworthy enough to ship. Agent quality in this domain is won on evals, not just code, and you will own that practice for the team. BigCommerce, part of the Commerce brand family, helps merchants increase sales at every stage of their growth. From small startups to mid-market businesses and large enterprises, we provide the leading e-commerce platform. Our customers can then concentrate on what's most important: growing their businesses. We enable our customers to build, innovate, and grow, collectively reshaping the e-commerce industry.

What You'll Do

• Design, build, and iterate on AI agents in Go/Python using an orchestrator/sub-agent architecture, covering intent interpretation, delegation, and safe action execution
• Own eval-driven development: build and maintain golden datasets, scorers, and regression suites (Braintrust or similar) for critical quality metrics such as discovery recall and quote accuracy
• Develop and refine prompts, model configurations; treat prompts and model settings as versioned, tested artifacts
• Integrate agents with MCP servers and backend tools, defining safe tool-call contracts, approval flows for write actions, and guardrails against prompt injection and abuse
• Instrument agents with tracing, metrics, and cost tracking; use production signals to drive quality improvements
• Collaborate with product designers and frontend engineers to deliver intuitive, useful conversational experiences
• Quickly build proof-of-concept agents to validate user stories, then harden them to GA quality
• Drive architecture decisions on ambiguous problems and mentor other engineers in agent engineering practices

Who Are You

• 5+ years of experience in backend or full-stack software development, with hands-on experience building agentic AI/LLM applications
• Education: Preferred minimum Bachelor's degree in CS, EE, SW, CE, MIS; or equivalent experience
• Strong and proven development skills in any major language (Go/Python/Ruby/PHP)
• Experience working with LLMs (Gemini, Anthropic, OpenAI, etc.) in production systems
• Experience with LLM evaluation: building datasets, defining scorers/metrics, and using eval results to drive iteration
• Strong understanding of prompt engineering, tool/function calling, and agent orchestration patterns
• Deep experience designing and building APIs (gRPC, GraphQL, REST) and integrating data across systems
• Hands-on experience building MCP servers or LLM tool integrations
• Excellent problem-solving skills and ability to work in a fast-paced, exploratory environment
• Strong collaboration and communication skills in cross-functional teams
• Strong preference toward execution and delivery
• Preferred: Experience with agent frameworks (Google ADK, LangChain/LangGraph, Semantic Kernel, or similar)
• Preferred: Experience with evaluation/observability platforms (Braintrust, LangSmith, or similar)
• Preferred: Experience with RAG systems and retrieval quality tuning
• Preferred: Experience with e-commerce platforms or SaaS product development
• Preferred: Background in conversational AI or natural language processing

(Pay Transparency Range: $116,000.00 - $195,000.00)

#LI-REMOTE #LI-GC1

Work Where You Thrive

Commerce is a remote-first company. For team members in Austin, Atlanta, and London, we offer optional collaborative workspaces for team gatherings, workshops, and in-person connection. Use them whenever they're helpful, balancing focused individual work with meaningful in-person collaboration.

Compensation Transparency

The national base salary range for this role is posted above in this job post. Final compensation will be determined based on factors such as relevant experience, skills, qualifications and geographic location. We also consider internal equity to help ensure fair and consistent pay practices across our teams. Where applicable, this role may also be eligible for variable compensation (such as bonus or commission), equity, and benefits in accordance with local policies. Details will be shared during the hiring process. We are committed to equitable and transparent pay practices that align to market data, internal equity, and individual contribution.

Inclusion and Belonging

At Commerce, we believe that celebrating the unique histories, perspectives and abilities of every employee makes a difference for our company, our customers and our community. We are an