Senior Android Engineer Jobs in Colorado (NOW HIRING)

This is an exciting opportunity to join an early stage company of talented engineers and designers, led by seasoned climate tech veterans. At Zero, Engineers are individual contributors that report to a Lead Engineer. You will work in small teams (designer, product representative, 1-2 engineers, and a lead engineer) in six-week cycles, to take well-scoped projects and deliver new features with guidance and review from senior engineers on your team. You execute within an approach shaped with your team, bringing options and questions, and vetting technical approaches with senior members of the team. We are relentlessly focused on sustainable productivity. You should expect long stretches of deep work, minimal standing meetings, effective in person collaboration with stakeholders and peers, as well as flexibility around your personal life.

You will help build our consumer mobile app, which enables homeowners to get a design and quote for their HVAC project without an in person sales visit. The mobile app is our most important digital touchpoint with homeowners, and you will own features end-to-end on iOS and/or Android. Today the app is built fully native with SwiftUI and Jetpack Compose, and the groundwork has been laid for rapid iteration and innovation.

You are strong on at least one mobile platform — iOS (Swift/SwiftUI) or Android (Kotlin/Jetpack Compose) — and eager to grow into the other. You have at least one year of professional software engineering experience, with meaningful time spent building native mobile applications that real users rely on.

You have strong opinions about AI in the mobile development loop. Agentic coding tools - Claude Code, Cursor, Codex, and whatever comes next - are a core part of how you work. You have a point of view on which problems they're great at, where they fall down, and when to keep a human in the loop on review and verification. You treat your AI toolchain the way a craftsperson treats their workshop: opinionated, evolving, and always sharpened.

You engineer solutions you're proud to put in front of real users. You lean on tests, established patterns, and your teammates' review to ship work that holds up in production. You'd rather reuse a sound solution than invent a novel one and when something breaks, you make sure the fix stays fixed.

You are relentlessly customer-centric. When a real user hits a bug, you want to know immediately, and you are happy to drop your in-flight work to unblock them. You see customer-reported bugs as the most important signal you get, not a distraction from your roadmap. Production problems are part of the job, not an interruption to it.

You dig into the rough edges real users hit and turn what you find into concrete solutions you propose to your team to ship. You're developing your judgment for the difference between recklessness and accepted risk and are developing the skills to be an effective engineer in a rapidly growing business.

You care about observability. Before a feature ships, you think about how you'll measure it - what events to instrument, what dashboard to watch, and what the signal looks like for "working" vs "broken." You're excited to work with a product analytics platform (we use PostHog) and view a live, populated dashboard as the reward for what you've built, not a follow-up ticket.

You are enthusiastic about in-person work and collaborating with your colleagues in front of a whiteboard. You live within 50 miles of Denver, CO or are willing to relocate.

• Full stack experience - comfortable standing up backend services (push notification servers, lightweight APIs, Cloud Functions) to support mobile features without waiting on another team
• Experience collaborating on creating and triaging REST APIs with backend counterparts
• Experience at early-stage startups and/or fast-growing environments
• Experience with on-device ML and AR (ARKit, ARCore)
• Experience with camera frameworks and computer vision
• Math background or practical data science experience
• Experience in climate tech