Senior AI Builder

Job Overview

We're seeking a Senior AI Builder to join our Engineering team at EarnIn. As a pioneer in earned wage access, we're building AI-native engineering capabilities to enhance our products and services.

Position Summary

The successful candidate will work at the intersection of platform engineering, developer experience, and applied AI. You'll partner with architects, domain leads, and product engineers to build tools, patterns, and guardrails that enable fast, safe, and durable AI adoption.

Responsibilities

• Design and build agents that take real actions, including prompts, reasoning chains, tool calls, and architecture
• Develop production infrastructure, including MCP servers, agent scaffolding, context harnesses, and a Skills Marketplace
• Challenge and improve the product development lifecycle by replacing manual friction with agentic workflows
• Build evaluation infrastructure, including pipelines, benchmarks, and quality gates
• Create reusable libraries, templates, and reference implementations for AI integration

What Success Looks Like

• Teams across engineering can ship AI-assisted features faster, with fewer rework loops
• Harnesses built are actively used and well-documented
• AI pilot quality and safety metrics are visible, trustworthy, and improving

Requirements

• 4+ years of full-time software engineering experience, with at least 2 years building tooling, platforms, or internal developer products
• Bachelor's, Master's, or PhD in Computer Science, Computer Engineering, or a related technical discipline, or equivalent industry experience
• Hands-on experience with LLM integration patterns, prompt engineering, RAG pipelines, tool/function calling, and agent architectures
• Proficiency and comfort working across the stack when needed
• Experience with MCP, LangChain, or comparable orchestration frameworks
• Experience with open source LLM models

Nice to Have

• Hands-on experience with reinforcement learning, especially RLHF, RLAIF, or reward modeling in applied product contexts
• Experience in fintech or regulated/security-sensitive environments
• Hands-on work with AI governance, bias evaluation, audit logging, model cards
• Exposure to multi-step reasoning pipelines or human-in-the-loop system design

Benefits

The Mountain View base salary range for this full-time position is $228,000 - $279,000, plus equity and benefits. This is a hybrid position in Mountain View that requires in-office work 2 days a week.