Mobile Software Engineer - Kotlin

Mercor; San Francisco (CA); On-site; USD 180,000 - 230,000; Full time

Job summary

Cincinnatus LLC is seeking a Staff Software Engineer to join a mobile-first team building native Android and iOS apps, with contributions to backend services, APIs, and web experiences. You will own features end-to-end and work with AI coding tools to accelerate delivery.

The role requires 4+ years of software experience, strong mobile skills in Kotlin (Android) and optional Swift, plus collaboration with Product and UX teams. W-2 employment placed within an enterprise client, 40 hours weekly.

Qualifications

• 4+ years of professional software engineering experience.
• Hands-on native mobile experience: Android (Kotlin) and optionally iOS/Swift.
• Backend, API, or web app exposure.
• Strong fundamentals: design, testing, debugging.
• Familiar with AI coding tools such as Copilot, Cursor, or Claude.
• Engage reliably for 40 hours/week.

Responsibilities

• Build and ship features for the team's native mobile apps, mainly Android in Kotlin.
• Contribute beyond mobile to backend services, APIs, and web applications.
• Use AI-powered developer tools to learn unfamiliar code and ship with quality.
• Participate in technical design, code reviews, and production support.
• Collaborate with Product, UX, and partner teams; help grow other engineers.

Skills

Android

Kotlin

iOS

APIs

Code reviews

AI tools

Teamwork

Tools

Copilot

Cursor

Claude

Job description

Join a product engineering team building native mobile and full-stack experiences used by customers every day.

1. Overview

We're partnering with a large enterprise technology organization to place a Staff Software Engineer on the team behind its Android and iOS apps. It's a mobile-first role, but engineers here also pitch in on backend services, APIs, and web, and use AI coding tools as a normal part of their day. If you enjoy owning features end to end and learning new parts of the stack, this is a great fit. This is a full-time commitment of 40 hours per week.

This is a W-2 employment position with Cincinnatus LLC, with the opportunity to be placed within a leading enterprise client's engineering organization as part of their extended workforce.

2. Key Responsibilities

• Build and ship features for the team's native mobile apps, mainly Android in Kotlin.

• Contribute beyond mobile when needed, across backend services, APIs, and web applications.

• Use AI-powered developer tools to get up to speed on unfamiliar code and ship with quality.

• Take part in technical design, code reviews, and production support.

• Work closely with Product, UX, and partner engineering teams, and help other engineers grow.

3. Core Qualifications

• 4+ years of professional software engineering experience.

• Hands-on native mobile experience, ideally Android with Kotlin and Jetpack. iOS/Swift is welcome too, and Flutter or React Native experience counts if you've also done some native work.

• Some production experience outside mobile, such as backend services, APIs, or web apps.

• Solid engineering fundamentals: design, testing, and debugging.

• Comfortable using AI coding tools such as Copilot, Cursor, or Claude.

• Ability to engage reliably for at least 40 hours/week during weekdays.

• Clear communication and a collaborative, curious mindset.

Nice to have: exposure to LLM-powered features (RAG, embeddings, agents), experience with accessibility standards, or work on apps with accounts, payments, or orders. You don't need all of these to apply.

About Cincinnatus LLC:Cincinnatus LLC is an enterprise staffing company that partners with leading technology companies to source and employ highly skilled professionals for contingent and contract-based opportunities. Cincinnatus serves as the employer of record for these engagements, providing W-2 employment, payroll, benefits, and compliance, while placing employees directly within client teams to work on high-impact initiatives.

Equal Employment Opportunity:Cincinnatus is proud to be an Equal Employment Opportunity employer. We do not discriminate based upon race, religion, color, national origin, sex (including pregnancy, childbirth, reproductive health decisions, or related medical conditions), sexual orientation, gender identity, gender expression, age, status as a protected veteran, status as an individual with a disability, genetic information, political views or activity, or any other legally protected characteristic.