Senior Kotlin Engineer

Avenue3; Leeds; On-site; GBP 60,000 - 100,000; Full time

Benefits offered by this job

Competitive salary

Company pension

Growth opportunities

Inclusive culture

Job summary

Avenue3 in Yorkshire is seeking a Senior Engineer who blends strong hands-on Kotlin skills with a customer-focused mindset to deliver high-quality software in complex, often high-latency environments. You will write Kotlin code, contribute to sound technical decisions and help clients move forward with confidence.

You’ll thrive in agile, multidisciplinary teams where requirements aren’t always fully defined, shaping pragmatic solutions and taking ownership of features from design to production.

Qualifications

• Experience delivering cross-platform applications using Kotlin Multiplatform.
• Ability to design-end-to-end features from conception to production.
• Strong collaboration with product owners, architects and clients.

Responsibilities

• Design, build and maintain robust cross-platform applications using Kotlin Multiplatform and Compose Multiplatform, owning features end-to-end from design through to production across Android and desktop (Windows/macOS/Linux) targets.
• Work across shared business logic and platform-specific implementations using Kotlin's expect/actual pattern, touching networking, local storage and device-integration layers.
• Build and ship applications that sync reliably in disconnected and high-latency environments, applying strong DevOps practices, CI/CD pipelines and Gradle-based build tooling.
• Deliver clean, well-tested, maintainable code, with appropriate automated testing across the SDLC.
• Investigate and resolve issues across the stack, including in production, with a calm, methodical approach.
• Mentor and support less experienced engineers through pairing, code review and day-to-day collaboration.
• Contribute to a culture of quality, curiosity and continuous improvement within the team.

Skills

Kotlin

Kotlin Multiplatform

Compose Multiplatform

Android

CI/CD

Gradle

Automated testing

DevOps practices

Tools

Gradle

CI/CD pipelines

Kotlin tooling

Job description

Who are we?

Avenue3 is a Yorkshire-based digital consultancy specialising in open data, modern engineering and the transformation of complex systems across health, government and regulated sectors. We bring deep expertise across strategy, discovery, architecture and engineering, helping organisations modernise systems and adopt open data standards for long-term interoperability.

Who are we?

Avenue3 is a Yorkshire-based digital consultancy specialising in open data, modern engineering and the transformation of complex systems across health, government and regulated sectors. We bring deep expertise across strategy, discovery, architecture and engineering, helping organisations modernise systems and adopt open data standards for long-term interoperability.

The opportunity

At Avenue3, we’re looking for a Senior Engineer who combines strong hands-on technical skills with a thoughtful, customer-focused mindset. This role is about delivering high-quality software in complex, often disconnected or high-latency environments, writing great Kotlin code, contributing to sound technical decisions and helping our clients move forward with confidence.

You’ll thrive in agile, multidisciplinary teams where requirements aren’t always fully defined, using your experience to ask the right questions, shape pragmatic solutions and translate ideas into robust, maintainable software. You’ll work closely with architects, product owners and client stakeholders, taking ownership of features and components from design through to production.

Alongside delivery, you’ll help raise the bar across the team, through code review, mentoring less experienced engineers, and contributing to the standards and patterns we use across Avenue3.

Core Responsibilities

Engineering & Delivery

• Design, build and maintain robust cross-platform applications using Kotlin Multiplatform and Compose Multiplatform, owning features end-to-end from design through to production across Android and desktop (Windows/macOS/Linux) targets.


• Work across shared business logic and platform-specific implementations using Kotlin's expect/actual pattern, touching networking, local storage and device-integration layers.


• Build and ship applications that sync reliably in disconnected and high-latency environments, applying strong DevOps practices, CI/CD pipelines and Gradle-based build tooling.


• Deliver clean, well-tested, maintainable code, with appropriate automated testing across the SDLC.


• Investigate and resolve issues across the stack, including in production, with a calm, methodical approach.

Technical Decision-Making

• Contribute to technical design discussions and implementation plans, bringing pragmatic, well-reasoned options to the table.


• Make sound day-to-day decisions on libraries, patterns and approaches within the boundaries set by the wider architecture.


• Help uphold engineering standards, ensuring services are scalable, secure, observable and interoperable.


• Identify technical risks and debt early, and work with the team to address them in a structured way.

Collaboration & Client Engagement

• Work closely with product owners, designers, architects and client teams to refine requirements and shape solutions that meet user and business needs.


• Communicate technical concepts clearly to both technical and non-technical audiences.


• Participate confidently in design sessions, refinements, show & tells and other delivery ceremonies.


• Represent Avenue3 well with clients. Professional, constructive and focused on outcomes.

Commercial Awareness & Value Creation

• Build an understanding of client organisations, their goals and the context in which they operate.


• Spot opportunities to add value beyond immediate tickets. Improvements to architecture, delivery flow, tooling or operational efficiency, and raise them with delivery and technical leads.


• Balance technical decisions with practical considerations of cost, complexity and effort, so solutions are robust without being over-engineered.


• Support proposals, estimates and discovery activities where engineering input is needed.

Growth, Mentoring & Team Development

• Mentor and support less experienced engineers through pairing, code review and day-to-day collaboration.


• Contribute to a culture of quality, curiosity and continuous improvement within the team.


• Take an active role in retrospectives, technical discussions and team learning.


• Contribute to internal knowledge-sharing, engineering playbooks and communities of practice.

Benefits And Culture

This role offers a competitive salary alongside a company pension and clear opportunities for ongoing growth. We foster an inclusive, supportive culture where engineering excellence, personal development and innovation are valued - and where people are trusted to deliver meaningful impact in a collaborative, open environment.