Senior AI Builder

About EarnIn

As one of the first pioneers of earned wage access, EarnIn builds products that deliver real-time financial flexibility for people living paycheck to paycheck. Community members access their earnings as they earn them, with options to spend, save, and grow their money without mandatory fees, interest rates, or credit checks. EarnIn has an experienced leadership team, world-class funding partners including A16Z, Matrix Partners, DST, and Ribbit Capital, and a healthy core business with substantial runway.

EarnIn is becoming an AI-native company, embedding AI agents into how the organization builds, analyzes, and operates across every function. Teams use AI Agents to move from ideas to execution faster, letting agents handle repetitive tasks so people can focus on judgment, creativity, and hard problems. This is paired with strict review and security guardrails appropriate to the regulated financial environment, with continued focus on privacy and the people who rely on EarnIn's products.

Position Summary

EarnIn is making AI-native engineering a core capability — not an initiative, but how the company designs, builds, and ships. This role seeks an AI builder who also writes great software — someone who looks at every step of how EarnIn designs, builds, tests, and ships, and asks why an agent isn't doing it. This is not a side project. The agents and harnesses built here will run in production, making real decisions for real people who depend on EarnIn to access their pay when it matters most.

You'll work at the intersection of platform engineering, developer experience, and applied AI — partnering with architects, domain leads, and product engineers to build the tools, patterns, and guardrails that make AI adoption fast, safe, and durable.

Location & Schedule: Hybrid in Mountain View; requires in-office work 2 days a week

Compensation: Mountain View base salary range of $228,000 - $279,000, plus equity and benefits. Salary ranges are determined by role, level, and location.

What You'll Do

Agents that take real actions. Design how agents think — prompts, reasoning chains, tool calls, and the full architecture beneath them. From MCP servers and agent scaffolding to context harnesses and a Skills Marketplace, you're building the layer every squad at EarnIn builds on. Not a proof of concept. Production infrastructure.

A PDLC that doesn't look like 2022. The product development lifecycle is overdue for a rethink. Challenge each stage — from scoping and design through to review, testing, deployment, and monitoring — and replace manual friction with agentic workflows wherever it makes sense. Build evaluation pipelines, automated PR hygiene, deployment gating, and generation-to-merge metrics — the scaffolding that makes governed AI fast, not slow.

Evals that actually mean something. Own the evaluation infrastructure — building the pipelines, benchmarks, and quality gates that show whether AI is working, degrading, or ready to ship. Design eval harnesses for AI-assisted workflows, set generation-to-merge and review latency baselines, and make model quality visible and trustworthy across teams.

Pilots that graduate to production. EarnIn's engineering leads are running experiments. Be the person who takes what's working and turns it into something the next team can fork and ship in a week. Build reusable libraries, templates, and reference implementations that give squads a running start on AI integration, so no one has to solve the same problem twice.

What Success Looks Like

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

What We're Looking For

• 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
• Strong opinions about developer experience and a track record of building things other engineers actually use

You'll Stand Out If You 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

AI Use in the Interview Process

EarnIn encourages you to use AI tools throughout much of the interview process. If you use AI during the live interview, simply mention how it helped and why you are using it. EarnIn is evaluating your judgment, reasoning, and ability to own and defend your work, not whether AI was involved. Some rounds, particularly those focused on your career history and past experiences, will not allow the use of AI — you'll be notified in advance. When in doubt, ask your recruiter or interviewer directly.

Diversity & Non-Discrimination

EarnIn believes that the best way to build a financial system that works for everyday people is by hiring a team that represents the diverse community served. The team is diverse in background, experience, and perspective. EarnIn does not unlawfully discriminate based on race, color, religion, sex (including pregnancy, childbirth, breastfeeding, or related medical conditions), gender identity, gender expression, national origin, ancestry, citizenship, age, physical or mental disability, legally protected medical condition, family care status, military or veteran status, marital status, registered domestic partner status, sexual orientation, genetic information, or any other basis protected by local, state, or federal laws. EarnIn is an E-Verify participant.

EarnIn does not accept unsolicited resumes from individual recruiters or third-party recruiting agencies in response to job postings. No fee will be paid to third parties who submit unsolicited candidates directly to EarnIn's hiring managers or HR team.