Senior Kotlin Developer

Role Description

We are building the software that drone pilots actually look at. The application runs on the aircraft's smart controller — DJI RC Pro / RC Plus class hardware — as an Android app with a Kotlin presentation layer, sitting on top of a shared Kotlin Multiplatform core that also powers our backend.

This role is front-end first. You own the interface: live telemetry, video, mission state, and the controls a pilot uses in the field. You will also co-own the shared KMP core with the rest of the team — the domain model, protocol and sync logic that the UI renders and the backend serves.

We do not have a designer yet. The right person here has opinions about interface design and can carry a screen from rough intent to something a pilot can use in bright sunlight with one hand — working with a designer later, but not blocked without one today.

This is a senior individual contributor role. You are not managing anyone; you are expected to make good calls independently and raise the quality bar by example.

What you will do

• Build and own the Android presentation layer in Kotlin and Compose: flight UI, telemetry displays, video, mission planning and review.
• Shape the interface itself — layout, interaction, information hierarchy — in the absence of a dedicated designer.
• Co-own the shared Kotlin Multiplatform core alongside the rest of the team: domain model, protocol, persistence, sync.
• Render live telemetry and video streams smoothly on modest controller hardware.
• Design for the field: degraded links, stale data, gloves, sunlight, vibration, one-handed use.
• Work alongside the engineers handling the DJI SDK integration, and consume the flight state they expose — growing into that layer yourself over time if it interests you.
• Validate on real hardware. The emulator only gets you so far; expect to be part of field testing.

Qualifications

• 5+ years building and shipping production software.
• Expert-level Kotlin: coroutines, structured concurrency, Flow, generics.
• Sound architecture instincts: modularization, clear layer boundaries, domain logic kept out of framework and UI code.
• Comfortable with testing and CI/CD as part of normal work, not an afterthought.
• Able to work autonomously in a fully remote, distributed team, and to communicate clearly in writing.
• Professional working proficiency in English.
• 4+ years of Android development with applications shipped and maintained in production.
• Solid grasp of the application lifecycle, foreground and bound services, process death, and keeping a long-running session alive behind the UI.
• Performance work as a habit: profiling, memory, frame timing, battery and thermal behaviour on constrained devices.
• Comfortable targeting older API levels and non-standard hardware.
• Deep Jetpack Compose: state hoisting, recomposition and stability, DerivedSoft, custom layouts, Canvas drawing, animation, gesture handling.
• Sound UI architecture: unidirectional data flow, a single source of truth, Flow-driven state, no business logic in composables.
• Rendering high-frequency streams without dropping frames.
• Composing UI over live video and map surfaces.
• Custom visual components built from scratch.
• Design judgment: producing defensible interfaces under time pressure.
• Designing for degraded states.
• Accessibility and internationalization fundamentals; UI testing.
• Production experience with KMP, not just prototypes.
• Confident with expect/actual, source set layout, and Gradle multiplatform configuration.
• The KMP ecosystem in practice.
• Judgment about shared code versus platform code.
• Offline-first patterns.
• Experience building UI on top of a device or hardware SDK.
• Handling connection lifecycle in the UI.
• Live video in an app: decoding, rendering, latency.
• Comfort with a UI whose correctness matters.

Requirements

• DJI SDK experience — Mobile SDK v5 especially, or Payload / Edge SDK.
• Any drone or autopilot exposure: MAVLink, PX4, ArduPilot, Skydio, Parrot; or hands-on flying.
• Compose Multiplatform.
• Geospatial and map UI experience.
• Video transport knowledge.
• Design tooling and vocabulary — Figma, design systems, prototyping.
• Server-side Kotlin (Ktor or Spring Boot).
• Android on vendor-locked or rugged hardware.
• A drone pilot certificate, or genuine willingness to obtain one.

Benefits

• Opportunities for certification and training.
• Dual monitor setup and high-spec workstations.
• English courses.
• Gym allowance.
• Medical Reimbursement.
• Full salary covered up to 20 days of sickness.
• Flexible working hours.
• Loyalty scheme.
• Team-building activities, special events and conferences.
• UK/EU Travel opportunities.
• Snacks and drinks in the office.