Software Engineer Intern - Backend & AI

Location: In-person, SF or Remote

Requirement: Pursuing Bachelors in Computer Science from Top US Unverisity (Stanford, Berkeley, MIT, GeorgiaTech, etc.)

Stack: Python, FastAPI, PostgreSQL, AWS (ECS, Fargate), Qdrant, TypeScript

What You’ll Work On

Backend Infrastructure:

• Building and scaling services in Python (FastAPI) with PostgreSQL as our primary database.
• Managing AWS infrastructure — primarily ECS/Fargate, Lambda, S3, and related services.
• Designing APIs for our frontend (TypeScript) and partner integrations.

AI/ML Engineering:

• Building agentic workflows and pipelines for large-scale LLM calls (OpenAI, Gemini, Perplexity).
• Designing and maintaining RAG (Retrieval-Augmented Generation) systems using Qdrant for vector search.
• Optimizing prompt engineering, retrieval strategies, and evaluation systems.

The ROLE

You are not just an employee – you are a builder of the company.

You’ll be at the core of shaping Relixir’s product, technology, and trajectory – from hands-on backend and AI engineering, to collaborating on the big decisions that define our future.

• Strategic Impact – Work directly with the founders to influence technical and product direction, deciding how we scale our platform and what bets we make in AI search automation.
• End-to-End Ownership – Take ideas from rough concept to production-ready systems – APIs, infrastructure, AI agents, and everything in between. You’ll own critical backend modules and ensure they’re fast, reliable, and a joy to use.
• AI Systems Engineering – Design and deploy large-scale AI workflows – multi-agent pipelines, RAG architectures with Qdrant, and high-volume LLM call orchestration.
• Customer-Driven Development – Talk to customers, dig into their needs, and turn feedback into technical solutions that directly impact their growth.

About You

• Deeply Curious — You actively seek to understand complex systems, customer problems, and the latest technical possibilities. Curiosity drives your best work.
• Relentlessly Driven — You thrive in early-stage chaos. You move quickly, test bold ideas, and turn uncertainty into working solutions.
• True Owner — You don’t just “complete tickets.” You take full responsibility for delivering outcomes — finding a path forward even with incomplete information.
• Collaborative & Humble — You share ideas openly, listen actively, and care more about the best solution than being right. You’re confident in your skills but always learning.

Must-Haves

• In-person SF
• High-agency
• Experience building backend & AI software for VC-backed startups
• Strong proficiency in Python and TypeScript
• Experience with Docker, FastAPI, PostgreSQL, and AWS
• Built and deployed a complex agentic/LLM-backed (context engineering, RAG with vector db) into production to customers
• Have completed at least one 0 -> 1 journey of a functional product

Nice-to-haves:

• Experience working with any of AWS ECS + SQS + Fargate, QDrant, LangChain
• Entrepreneurial Mindset: Ex-founder or future founder

Why This Role is Special

We're growing 166% MoM, onboarding monster logos (Rippling, Airwallex, Hackerrank, etc.), supporting global marketing teams, and on our way to Series A by EOY.

This August, I'm looking for the most cracked top 1% founding engineers and founding customer success/ops to join our rocketship 🚀


Here's my pitch to you:

1. Our product is far ahead of the competition. Companies are switching to us every week because they see the differentiation & immediate value.
2. Revenue pipeline is already at $X,000,000 <2 months since launch and rapidly growing. There's simply more customers than we can handle.
3. Customers now see Relixir as the unified solution to automate their entire SEO/GEO Growth Marketing function: a $400B market opportunity.
4. We're backed by Y Combinator and legendary operating investors like z21 Ventures who have built unicorns from scratch.
   
   
   Lastly, our team is a group of nonchalant, hardworking, super chill college dropouts from Berkeley who have scaled and even exited previous companies for 7-figures.

About the interview

1. Intro call with founders (15-30 min)
2. Technical interview with CTO
3. Recieve offer

About Relixir

Relixir is the autonomous search share maximization platform helping 40+ B2B companies rank #1 across Google and AI search engines. We're Berkeley alums and one of the fastest growing companies from YC X25 batch.