Senior Developer

Rapsodo Inc.; St. Louis (MO); On-site; USD 110,000 - 150,000; Full time

Job summary

Rapsodo Inc. in St. Louis seeks an experienced engineer with 8+ years in mobile development, specializing in Kotlin Multiplatform. The role demands proficiency in AI-assisted development, architecture design, and integration. Candidates must have a Bachelor's or Master's degree in a relevant field and be able to translate complex technical decisions into clear specifications. The position emphasizes collaboration across cross-functional teams, enhancing developer experience, and maintaining high standards for code quality.

Qualifications

• 8+ years of mobile development experience with deep familiarity across both Android and iOS ecosystems.
• 3+ years shipping Kotlin Multiplatform in production.
• Strong command of Kotlin Coroutines, Flow, and cross-platform concurrency models.

Responsibilities

• Champion AI‑assisted development across architecture, design, and implementation.
• Assure architectural scoping and define migration strategies from legacy implementations.
• Build and maintain a living knowledge base—architecture documentation, system diagrams.

Skills

Mobile development experience

Deep familiarity with Android and iOS ecosystems

Kotlin Multiplatform experience

AI-assisted development tools

Strong communication skills

Education

Bachelor’s or Master’s degree in Computer Science, Engineering, or a related field

Tools

Kotlin

Gradle

CI/CD pipelines

Koin or equivalent for dependency injection

Job description

Company Overview

With its headquarters in Singapore and strategically placed offices across the United States, Turkey, Japan, and Malaysia, Rapsodo represents more than just sports technology and data analytics. It stands as the clear front-runner in providing affordable, professional-grade technology for athletes aiming to enhance their performance.

The company currently collaborates with partners such as The PGA of America, Golf Digest, Troon, various Major League Baseball teams, USA Baseball, and over 1000 NCAA athletic departments.

Become a part of Team Rapsodo as we challenge limits and unveil endless potential, one data point and one heartwarming success story at a time.

Powered by Athletes who get it, and Engineers who can do it.

Role Purpose

This role exists to be the connective tissue between cross‑functional teams, translating complex system trade‑offs into clear decisions and embedding AI‑assisted development into how we build. This is a role for an engineer who thinks in systems, executes with precision, and communicates with clarity.

Key Responsibilities

• Champion AI‑assisted development across architecture, design, and implementation—driving adoption and establishing the practices that make it last.
• Define and own best practices for AI‑assisted system design, code generation, documentation, and testing.
• Assess and integrate AI tooling into the development lifecycle with a focus on security, scalability, and long‑term maintainability.
• Assess incoming feature requests and determine technical feasibility within the Kotlin Multiplatform codebase.
• Own architectural scoping—articulating trade‑offs and risks, particularly at the boundary between shared and platform‑specific code.
• Design and document scalable architectures that clearly define module boundaries, data flow, threading models, and dependency injection strategies.
• Lead KMP technical decision‑making, keeping solutions aligned with iOS and Android platform constraints and best practices.
• Define and execute migration strategies from legacy implementations to shared KMP modules where the trade‑off is justified.
• Coordinate cross‑functional dependencies across firmware, backend, Unity, and QA to maintain system‑wide consistency and delivery commitments.
• Build and maintain a living knowledge base—architecture documentation, system diagrams, and technical specs that teams actually use.
• Continuously improve developer experience through smarter tooling, build optimization, CI/CD, and modularization.
• Set and uphold high standards for code quality, testability, and maintainability across shared and platform‑specific code.

Role Qualifications

• Bachelor’s or Master’s degree in Computer Science, Engineering, or a related field.
• 8+ years of mobile development experience with deep familiarity across both Android and iOS ecosystems.
• 3+ years shipping Kotlin Multiplatform in production.
• Deep command of Clean Architecture, modularization, and separation of concerns in multi‑platform systems.
• Proven experience designing shared domain and data layers with well‑defined boundaries between shared logic and platform‑specific UI.
• Strong command of Kotlin Coroutines, Flow (StateFlow, SharedFlow), and cross‑platform concurrency models.
• Hands‑on experience with dependency injection (Koin or equivalent) in multi‑module environments.
• Familiarity with Compose Multiplatform and native UI frameworks (SwiftUI/UIKit, Jetpack Compose).
• Experience architecting networking and data layers in a multiplatform context, including offline‑first design, sync strategies, and caching.
• Strong understanding of KMP‑iOS interoperability and the nuances of designing APIs for Swift consumers.
• Solid experience with Gradle, dependency management, and CI/CD pipelines for multi‑platform projects.
• Experience building device‑connected applications (BLE, Wi‑Fi, TCP) with a focus on reliability and real‑time data handling.
• Proven ability to translate complex technical decisions into clear specifications that align cross‑functional teams.
• Strong communicator who can cut through complexity and align stakeholders across mobile, backend, firmware, and QA.
• Substantial hands‑on experience with AI‑assisted development tools and a track record of integrating them meaningfully into engineering workflows.
• Sharp judgment when evaluating AI‑generated outputs—knowing when to trust, when to verify, and when to rewrite.