About Citizen

Citizen is the No. 1 public safety app in the U.S., with a mission to make the world a safer place. Citizen provides 911 alerts so people can use their phones to keep themselves, and the people and places they love, safe. Citizen has notified people to evacuate burning buildings, deterred school buses from nearby terrorist attacks, and led to the rescue of kidnapped children and missing people. 

Citizen’s 911 alerts are accompanied by live stories, real-time updates, and user-generated content so app users never have to wonder why there are helicopters overhead or fire engines passing by. By broadcasting from the scene of an incident, communicating with one another, and reading live updates, communities are empowered by Citizen. We act fast, break news, and give people the immediate information they need to stay safe. And we’re just getting started.

Already relied on by millions of people every day, Citizen will expand even further across the United States this year to keep more users safe and informed. We’re looking for hardworking, mission-driven individuals to help bring Citizen to hundreds of cities nationwide.

Citizen is backed by Sequoia Capital, 8VC, Founders Fund, Goodwater Capital, and Greycroft and has raised $100M+ in VC funding.

Our Challenges

• Scaling & Bursting: With thousands of users joining the platform each day, we need to ensure our systems scale to handle expanded load gracefully. On significant events, we see over a million simultaneously connected clients and their associated live streams. Our core systems need to be able to efficiently support these traffic patterns and continue to scale to millions of more users in the future.
• Machine learning: We process thousands of hours of audio every day looking for incidents that impact our users’ safety. To do this at scale, we’ve built ML models for audio analysis and targeting using the current state of the art from academia.
• Analytics: We want to alert users to the incidents that matter to them, in a way that scales across different geographic densities and demographics.
• Mobile video streaming: Our app ingests high-quality video at low-latency, transcodes, and redistributes the video to external media outlets seamlessly.
• Radio hardware: We build our own software-defined radio-based devices to consume all radio dispatch in every major city, whether analog or digital.

Our Stack

• Mobile: Swift (iOS), Kotlin (Android)
• Web: React.js, TypeScript
• Services: Go for transactional systems; Python for analytical systems
• Datastores: Cassandra, MySQL, PostgreSQL, BigQuery, Memcached, Redis, Google PubSub
• Infrastructure: Google Cloud Platform

About the Role 

• Design and build systems for scale, modularity, and flexibility without compromising on reliability.
• Deliver backend systems with an attention to high availability, low latency and scalability.
• Build and operate infrastructure, toolset, and deployment pipelines. 
• Take operational responsibility for the services we build.
• Collaborate closely with a multidisciplinary team that consists of product, design and engineering team members to deliver a consistent experience to our users in real-time.
• Demonstrate rigor with code quality, best practices, and code review, while understanding product tradeoffs.

Requirements

• Bachelor’s Degree in Computer Science or related field. 
• 5+ years engineering experience, focusing primarily on backend development.
• Experience working with production code using languages such as C++, Go, Java, Python, Scala, etc.
• Experience designing and implementing performant APIs on distributed systems
• Strong knowledge of data design and database systems

Nice to Have

• Knowledge and hands on experience with Video Streaming Services
• Knowledge, exposure, or hands on experience with ML and related systems

Citizen is a fully-distributed team that offers a competitive benefits package including medical, dental, vision, flexible spending accounts, paid time off, company holidays, stock options, and various wellness perks.

Citizen is proud to be an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all.

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