Description
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
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 codebase, oversized modules, competing patterns, slow builds, flaky tests and turning them into high-impact projects with measurable outcomes
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
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
An interest in guiding, influencing, and growing other engineers — you raise the bar for everyone, not just your own code
A related technical degree required
Bonus Points
Experience using Slack and a keen interest in making it better
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
Prior experience on a centralized infrastructure or developer experience team, serving internal developer customers across multiple teams
Comfort working across platform boundaries — you've contributed to iOS, backend, or cross-platform tooling in addition to Android
Team Blog Posts
- Stabilize, Modularize, Modernize: Scaling Slack's Mobile Codebases
- Scaling Slack's Mobile Codebases: Modernization
- Extending Anvil for Fun and Profit
- Developing in the Open
For roles in San Francisco and Los Angeles: Pursuant to the San Francisco Fair Chance Ordinance and the Los Angeles Fair Chance Initiative for Hiring, Salesforce will consider for employment qualified applicants with arrest and conviction records.