Cocone Europe

About the Role

We're building the US/EU version of Livly Island, a mobile social game with 4+ years of live service history and 20,000+ content assets. You'll be the first backend engineer on the UK team, taking ownership of a mature Go-based microservices platform and leading it toward full technical independence.

What You'll Do

• Own and operate the backend infrastructure: deployment, monitoring, incident response
• Work with the existing Go codebase (4 services: main API, realtime chat, CMS admin panel, data validation tooling)
• Set up and manage new region cloud infrastructure (AWS + GCP)
• Collaborate with HQ's engineering team during knowledge transfer, then gradually take over backend ownership
• Hire and onboard additional backend engineers as the team grows
• Partner with the client engineers (Unity/C#) to ship features for the market launch

Must Have

• 5+ years backend development, 3+ years with Go
• Production experience with gRPC and Protocol Buffers
• Strong MongoDB experience (replica sets, read preference, performance tuning)
• Redis (cluster mode, pub/sub, caching patterns)
• Cloud infrastructure: AWS (S3, CloudFront, ECS, Lambda) and/or GCP (Compute Engine, Cloud Storage)
• Docker, CI/CD pipelines (GitHub Actions)
• Comfortable being the sole backend engineer initially — you debug, deploy, and firefight

Nice to Have

• Experience with mobile game backends or live service games
• Datadog / Prometheus / Stackdriver monitoring
• Japanese language ability (HQ communication, though English is primary)
• Experience with billing/payment integrations
• Terraform or infrastructure-as-code

Tech Stack

• Go 1.24+, gRPC, Protocol Buffers
• MongoDB, Redis Cluster
• AWS (S3, CloudFront, ECS, Lambda, CodeDeploy) + GCP (Compute Engine, Stackdriver)
• Docker, GitHub Actions, Jenkins
• Datadog APM, Prometheus, Scouter
• JWT auth, Firebase Cloud Messaging

What We Offer

• Full ownership of backend for a game launching in a new market
• Small, autonomous team with creative freedom
• Direct collaboration with experienced JP engineering team during handover
• Path to building and leading a backend team

About Us: COCONE EUROPE OÜ is the European subsidiary of Cocone Corporation, a Japanese company known for avatar-based social mobile experiences. We build consumer-facing mobile products focused on emotional connection, engagement, and long-term user relationships.

About the Role: We are looking for a Senior UI/UX Designer based in London (hybrid model) to take ownership of the user experience and interface design of a live mobile product on Android and iOS with built-in gamification.

This role is centered on reimagining and elevating the overall product experience. You will identify usability issues, rethink core flows, and drive improvements that enhance engagement, retention, and emotional connection. You will work closely with product managers, engineers, and artists to ensure that design decisions are grounded in user needs while supporting business objectives.

What You’ll Do

• Own and drive end-to-end UX/UI design for a consumer-facing mobile application built in Unity.
• Analyze existing user profiles and journeys to identify friction points, usability issues, and opportunities for improvement.
• Redesign and optimize core product experiences with a strong focus on engagement and long-term retention.
• Define UX hypotheses, validate them through testing, and iterate based on insights.
• Design user flows, information architecture, wireframes, and high-fidelity UI for key features and systems.
• Translate product goals and behavioral insights into intuitive and emotionally engaging user experiences.
• Collaborate closely with product and engineering teams to ensure designs are feasible and effectively implemented.
• Analyze user behavior data, usability testing results, and qualitative feedback to identify UX issues and opportunities.
• Conduct UX audits and establish clear recommendations for improving usability, consistency, and accessibility.
• Contribute to and evolve a cohesive design system to ensure consistency across the product.

Requirements

Experience

• 5+ years of professional UI/UX design experience for mobile applications.
• Proven experience working on live products, including improving and iterating on existing experiences.
• Experience owning UX for complex systems or feature sets, not just individual screens.
• Strong track record of collaboration with product managers and engineers.
• Experience contributing to product improvements tied to engagement or retention metrics.
• Creating scalable design systems.

Skills

• Deep understanding of UX principles, interaction design, and information architecture.
• Strong ability to diagnose UX problems and propose effective, scalable solutions.
• Solid understanding of mobile platform conventions and constraints (Android and iOS).
• Ability to clearly articulate design decisions and rationale.
• High proficiency with modern design tools (Figma or equivalent).
• Experience leveraging data, user feedback, and usability testing to guide design decisions.
• Strong visual design skills with attention to detail, hierarchy, and consistency.
• Understanding and ability to apply gamification principles in UX.

Soft Skills

• High level of ownership and accountability.
• Strong communication and cross-functional collaboration skills.
• Comfort working in an international environment.
• Proactive, problem-solving mindset.
• Strong attention to product quality and user experience.

Nice to Have

• Experience with social features, avatar systems, or emotionally-driven digital experiences.
• Familiarity with accessibility best practices.
• Experience contributing to or scaling design systems.
• Experience mentoring or guiding other designers.
• Experience implementing UI assets in Unity.

Interview Process

• Initial Interview (30–45 minutes)
• Practical Test (2–3 days)
• Design Review & Deep Dive (60–90 minutes)
• Final Interview & Offer Discussion (30–40 minutes)
• 2-Month Probation Period
• Full-Time Offer

How to Apply

• CV
• Portfolio showcasing UX process and shipped work (mandatory)