Senior Backend Engineer (Python & FastAPI)

Senior Backend Engineer – High-Scale Systems | Python & FastAPI | Security SaaSSalary: £75k - £85k plus bonusLocation: Fully remote, (UK-based)Sponsorship is not available for this rolePrism Digital have partnered with a super interesting and niche VC-backed client specialising in attack surface management and automated red teaming. Their platform provides organisations with real-time visibility into their attack surface and potential exploitable vulnerabilities.They have received numerous awards for being an up-and-coming security SaaS product company and show no signs of slowing down their growth. They've completed Series A funding, raising $29 million across three funding rounds, and are now seeking a Senior Backend Engineer.This role acts as the intersection between two teams - frontend software team and the security research team. You will be responsible for the entirety of the back end features of the products. You will be in charge of building scalable backend services and awesome messaging queues.You will be responsible for developing a Python-based back end platform that's handling 100,000+s of interactions daily. So the ideal candidate will come from a background of working with applications that are processing large amounts of data, transactions or instances daily.Key Requirements:PythonPreviously worked at a start up / smaller sized company5 years+ experienceAbility to build software which scalesBuilding messaging queues e.g., Kafka (nice to have)This is entirely a Python back-end development role (Python 3), where the core framework used is FastAPI and Kafka for the messaging queues. The data sits in PostreSQL and MongoDB.BenefitsUp to £85,000Fully remote28-day holidays (including bank holidays)Shares optionsPrivate health insurance via BupaCompetitive pensionSalary reviews every 12 monthsThis role does not accept applicants outside of the UK, nor does it offer sponsorshipSenior Backend Engineer | Python, FastAPI & Scaling | Security SaaSSeniority LevelMid-Senior levelIndustryTechnology, Information and MediaIT Services and IT ConsultingComputer and Network SecurityEmployment TypeFull-timeJob FunctionsEngineeringSkillsBack-End Web DevelopmentScalabilityDistributed SystemsPython (Programming LangSenior Backend Engineer – High-Scale Systems | Python & FastAPI | Security SaaS

Created: 2026-01-18