Senior Python Engineer

• Strong Python (Flask moving to FastAPI with Typing) Back End experience
• Proven experience building APIs within service-oriented architectures
• Solid SQL knowledge
• PostgreSQL
• AWS (Lambda, ECS)
• Docker
• Strong system design and data flow thinking
• Collaborative mindset with high coding standards

• Top-of-market salary
• Pension matched up to 7%
• Private medical + income protection
• 25 days holiday + hybrid working
• Work abroad up to 3 months per year
• Learning & development budget

London - £500 - £600 per day Contract Posted by: Arrows Group Professional Limited Posted: Tuesday, 17 February 2026 Senior Backend Engineer (Python) - AI Platform | High-Growth FinTech - £500 Outside IR35 - 6 month contract We're partnering with a rapidly scaling AI company transforming global debt markets. Their platform centralises proprietary credit data, deep analysis and high-value workflows for 300+ leading financial institutions worldwide. With strong product-market fit and rapid international expansion, they're hiring a Senior Backend (Python) Engineer to take technical ownership across high-impact projects. What You'll Do * Lead system design and deliver scalable Back End services * Build and evolve APIs, data processing pipelines and automation * Mentor engineers and run code reviews * Collaborate closely with Product and cross-functional domain experts * Continuously improve performance, quality and developer experience