Staff Software Engineer, Android
We are looking for people who are passionate about making it safe to go fast. The Mobile Guardrails team owns the guardrails, delivery signals, and observability that ensure Slack's mobile apps ship with confidence — whether the code is written by a human or an AI agent. We make the development process itself better: the build systems, the test infrastructure, the architectural enforcement, and the metrics that tell us where to invest next. We're looking for an engineer with strong Android foundations who thinks beyond any single platform — someone who sees mobile infrastructure as a connected system and wants to define what quality means at scale.
As a guardrails engineer, you think in systems, not features. You see a flaky test and think about quarantine infrastructure, not just a retry. You see a 400-file module and think about rebuild radii and dependency graphs, not just a refactor. You set a high bar for codebase health and take ownership beyond your immediate area — when something is slowing the team down, you fix the root cause, not just the symptom. You are energized by the intersection of developer tooling, AI-assisted development, and mobile platform engineering. You thrive in ambiguity, build for the long term, and measure what matters.
What You Should Have
7+ years of software engineering experience, with a strong foundation in Android development and significant time spent on infrastructure, tooling, or platform work in a large modular codebase.
A systems thinker. You trace problems to their root cause, detect recurring patterns across teams and codebases, and when you find a gap where infrastructure should exist, you build the system and make sure the team can rely on it.
A track record of bringing people along. You raise the bar through education, pairing, and influence, not just your own code.
Hands-on experience with performance tooling and observability, including profiling, build analysis, metrics dashboards, and using data to decide where to invest.
Proficiency with AI-assisted development. This is a requirement, not a nice-to-have. You use AI coding tools in your workflow and have opinions on making them effective at scale.
Experience working at scale in large modular codebases with complex dependency graphs and CI/CD pipelines where changes have org-wide blast radius.
A habit of learning, experimenting, and sharing. You try new approaches, validate them, and spread what you learn through write-ups, demos, or pairing.
An interest in guiding, influencing, and growing other engineers — you raise the bar for everyone, not just your own code
Proficiency with Kotlin and the Android ecosystem, but equally comfortable working in build systems, CI/CD pipelines, scripting, and tooling that spans platforms
Experience with build systems at scale — Gradle, Bazel, or similar — including build performance optimization, dependency management, and modularization strategies for codebases with hundreds of modules
A track record of identifying systemic problems in large codebases — oversized modules, competing patterns, slow builds, flaky tests — and turning them into high-impact projects with measurable outcomes
Familiarity with metrics and observability tools (e.g., Honeycomb, Grafana) for measuring build performance, test reliability, or developer productivity
Solid experience with automated testing strategies: unit, integration, and UI testing frameworks, smart test selection, and test stability management
Comfortable with scripting (Python, Bash, etc.) for build tooling, code generation, or developer workflow automation
A disciplined approach to development, testing, documentation, and code structure in a team environment
A related technical degree required
Bonus Points
Experience using Slack and a keen interest in making it better
Prior experience on a centralized infrastructure or developer experience team, serving internal developer customers across multiple teams
Experience designing and enforcing architectural patterns across a codebase (e.g., dependency injection frameworks, module layering, interface-only dependencies)
Hands-on experience building or significantly improving CI/CD pipelines, build observability, and developer workflow tooling — the systems that engineers use to validate their code every day
Comfort working across platform boundaries — you've contributed to iOS, backend, or cross-platform tooling in addition to Android
Experience with AI-assisted development tooling (Claude Code, Codex, or similar) — especially building the infrastructure, context, or guardrails that make AI agents more effective in large codebases
Team Blog Posts