Python Developer — Secure, Mission‑Critical Systems Defence & Security | Contract | Outside IR35 Build software that’s actually used — and actually matters. We’re looking for a Python Developer to work on secure, mission‑critical systems used across Defence & Security programmes. This is real production software, not prototypes or proof‑of‑concepts — built with care, discipline, and purpose. What you’ll do Build clean, reliable Python services in a secure environment Write well‑tested, maintainable code (pytest, CI/CD) Work from clear requirements and sound architecture Collaborate with experienced Senior and Lead Engineers Ship software that supports real‑world operations Tech & environment Python / pytest Automated testing & CI/CD pipelines Modern service‑based architectures and APIs Calm, professional engineering culture What we’re looking for Solid experience building production software Strong Python fundamentals and good engineering habits A quality‑first mindset Eligibility for UK Security Clearance (SC) Why this role Meaningful, high‑integrity work Strong technical leadership Modern engineering standards — no cowboy coding Outside IR35 contract If you’re a Python Developer who cares about doing things properly, this is a project worth your time.