Senior Software Engineer - Kotlin

Job Description

Senior Software Engineer - Kotlin on www.freelancermap.com Find projects Find freelancers Solutions Insights Log in Sign up Change availability Save Senior Software Engineer - Kotlin Formula Recruitment Contact person : Generic Network London , United Kingdom On-site Freelance Duration 6 months Apply now Save to watchlist Print Report Report project After submitting, you will receive a confirmation email. We will review your information and take action if necessary. Reason for reporting this project: * The project is outdated The project description is unprofessional / This is not a valid project Incorrect contract type The hourly rate is unrealistic Report project Report project Finance Kotlin Description Senior Software Engineer - Kotlin £550-£650 per day | Outside IR35 Hybrid | London (3 days onsite) A leading UK financial services organisation is seeking a Senior Software Engineer to play a central role in a large-scale platform transformation programme. The business is rebuilding a critical part of its digital infrastructure to support a broad range of transaction methods and channels across both in-person and digital environments. This is hands-on Back End engineering at scale, with real ownership and direct exposure to architecture decisions from day one. Key Responsibilities as a Senior Software Engineer: Design and build Kotlin Back End services for a new payments platform Own the architecture and design of key components, taking high-level requirements and turning them into structured, deliverable backlogs Write clean, well-tested, production-ready code that the team can rely on Work closely with Product and Engineering to break down complex problems and ship impactful features Bring fresh thinking to existing approaches and propose improvements where you see them Support team leadership across delivery, code quality, and technical decision-making Contribute to technical hiring, helping to assess and attract strong engineering talent Skills & Key Requirements: Strong commercial Kotlin experience for Back End development, ideally within payments or financial services Domain expertise in payment gateway systems or payments infrastructure Comfortable with React.js for full stack contribution where required Proven ability to take requirements through to architecture, design, and delivery Senior Software Engineer level ownership of technical decisions and delivery Clear grasp of software engineering fundamentals: design patterns, SOLID principles, test-first design Familiarity with Agile practices including peer code review and pair programming Hands-on exposure to AWS or comparable cloud platforms Background in both monolithic and microservices-based systems Experience in a product-led environment where engineering and business goals are closely aligned Contract Details: Day rate: up to £650 per day IR35: Outside IR35 Contract length: 6 months initial term, extension likely Location: London, hybrid (3 days onsite) Start: ASAP If you are a Senior Software Engineer with strong Kotlin Back End experience and interested in working in the financial services space, apply now or reach out directly to find out more. Due to the high volume of applications, not all applicants will receive feedback. Application form For freelancers Find projects Benefits for freelancers Prices and features Professional liability insurance For companies Find freelancers Benefits for companies Prices and features Help and support FAQ Contact Blog Freelancer study Company directory About freelancermap About us Testimonials © 2005 ‐ 2026 freelancermap GmbH, Nürnberg Data privacy Legal information Term and Conditions