At a Glance
- Tasks: Join a team to migrate a platform from C++ to Kotlin, tackling real technical challenges.
- Company: Established tech business known for high-performance software and strong engineering culture.
- Benefits: Earn up to £500 per day, enjoy hybrid work, and gain valuable experience.
- Other info: Collaborate with a senior team in a dynamic environment with potential for contract extension.
- Why this job: Be part of a mission-critical project with autonomy and impact on modern software architecture.
- Qualifications: 5+ years in software development, strong Kotlin skills, and ability to read C++ code.
Senior Kotlin developer role on a large-scale platform migration from C++ to Kotlin.
12-month contract, outside IR35. Up to £500 per day. Hybrid: 2 days per week in Belfast office, remainder remote. Market-leading project with real technical complexity and long-term runway.
Our client is an established technology business operating at scale, with a mature engineering function and a reputation for building robust, high-performance software. They are undertaking a significant platform modernisation programme, replacing a long-standing C++ codebase with a modern Kotlin architecture. This is a well-funded, strategically important initiative with full leadership backing.
You will join a cross-functional engineering team at the heart of this migration programme, working hands-on to re-architect and rebuild core platform components in Kotlin. This is a mission-critical body of work with genuine technical depth. You will collaborate closely with senior engineers and technical leads, contributing directly to design decisions and helping to set standards for the new platform. The right person will bring confidence, pragmatism, and a track record of delivering in complex, fast-moving environments.
Key Responsibilities:- Design and implement Kotlin components as part of the C++ to Kotlin platform migration.
- Analyse existing C++ systems and translate logic accurately into idiomatic Kotlin.
- Collaborate with architects and senior engineers to define migration patterns and standards.
- Write clean, well-tested, production-ready code with a focus on performance and maintainability.
- Contribute to code reviews, providing and receiving constructive technical feedback.
- Identify and resolve integration challenges between legacy and new platform components.
- Document technical decisions and migration progress for wider team visibility.
- Engage proactively with daily stand-ups, sprint planning, and cross-team communication.
- Essential:
- 5+ years of commercial software development experience.
- Strong, demonstrable Kotlin development skills in a production environment.
- Experience working on platform or systems-level software.
- Ability to read and understand C++ codebases (you do not need to write C++).
- Solid understanding of software architecture principles and design patterns.
- Comfortable working in an agile team with regular collaboration and communication.
- Eligible to work in the UK without sponsorship.
- Desirable / Nice to Have:
- Hands-on experience with C++ to modern language migration projects.
- Familiarity with JVM performance tuning or low-latency systems.
- Prior contract experience in a similar technical environment.
- Up to £500 per day, outside IR35.
- 12-month contract with strong potential for extension.
- Hybrid working: 2 days per week in Belfast, rest remote.
- Technically challenging migration with a meaningful scope and real engineering decisions.
- Senior, experienced team to work alongside.
- Market-leading client with a stable, well-funded programme.
- Clear project structure with genuine autonomy on how you approach the work.
If this sounds like your next contract, get in touch with Aaron at Ocho People. Send your CV or a brief note on your relevant experience.
Kotlin Contractor in Belfast employer: Ocho
Join a leading technology business in Belfast, where you will be part of a significant platform migration project that offers both technical complexity and the opportunity for professional growth. With a hybrid working model, competitive daily rates, and a collaborative culture, this role provides a unique chance to work alongside experienced engineers on a mission-critical initiative, ensuring your contributions are valued and impactful.
