Senior Python Engineer (AI Startup)

Some engineers enjoy writing code. Others can't stop building. If you've been programming since you were a teenager, spend your evenings experimenting with new technology, and get genuine satisfaction from shipping products, this role was written for you. Referment is partnering with a venture-backed AI startup looking for one exceptional engineer to help build the next generation of AI-powered cybersecurity products. You'll work directly with the founders and own features from customer problem through to production. You'll enjoy this role if you... Love building more than talking about buildingPrefer shipping software over writing documentationCan move between backend, frontend and infrastructure without thinking twiceGet excited by hard engineering challenges like building compilers, DSLs, or internal developer toolsUse AI every day, but don't rely on it to think for youEnjoy solving messy customer problems instead of perfectly defined tickets What You'll Be Building Rather than owning a small corner of a huge codebase, you'll own products end-to-end You'll design complex backend architecture and systems.Ship React interfaces.Build internal developer tools and agentic consoles.Improve databases and handle systems programming.Debug production and deploy continuously.Help shape both the product and the engineering culture. What We're Looking For Deep technical focus on hard engineering and complex backend architectureStrong Python backend fundamentals with high-level application of tools like FastAPI, Django, or FlaskSenior-level technical sophistication and the ability to move beyond routine maintenance tasksVerifiable track record of technical contributions and honest project claims (e.g. active GitHub or OSS presence)React experience or willingness to work across the frontendStartup mentality with genuine product ownershipAround 3-6 years' experience with a focus on engineering depth Extra points for experience with: Founding or leadership roles (e.g. Co-Founder or CTO)Building internal developer tools, DSLs, or compilersMulti-language proficiency (e.g. Go, C, or Rust)CybersecurityWorkflow orchestration (Prefect, Airflow)High-growth SaaS This probably isn't for you if... Your focus is primarily on product management or innovation titles rather than hands-on engineeringYou consider routine infrastructure maintenance to be your core focus areaYou need detailed specs before starting workYou only enjoy one part of the stackYou avoid production responsibilityYou're looking for a comfortable corporate engineering roleYou're currently splitting your attention with another startup Why join? Competitive salaryMeaningful equityOne of the first engineering hiresDirect access to the foundersHuge ownership from day oneBuild products that customers actually use #Referment