Senior Backend Engineer

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 flying 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.

Our flagship paid product—Citizen Premium—is a only-of-its-kind personal safety subscription that allows users to reach a digital guardian 24/7 for $20/mo. Subscribers used Citizen Premium to guide emergency response to remote hiking locations, or travel safely on late-night walks.

Citizen Plus, which sits between the free Citizen app and Citizen Premium at $6/mo, currently unlocks 6 new features. Available for the first time ever, Citizen Plus includes the powerful ability to listen to police and fire radios, customize your alerts, unlock past incidents, create alert zones, view nearby registered offenders, and see crime statistics.

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 8VC, Founders Fund, Goodwater Capital, and Greycroft and has raised $100M+ in VC funding.

Our Challenges

• Zero-to-One: There is no other company doing what Citizen does in the way that Citizen is doing it. There is no playbook for building a consumer public safety product, so we learn and adapt as we go. We build fast, learn quickly, and rapidly iterate until we get it right.

• Scaling & Bursting: During significant events, we see hundreds of thousands of simultaneously connected users and their associated live streams. Seconds matter in safety and our core systems must efficiently support these traffic patterns to give our users the information they need when it matters most.

• Machine Learning: We process thousands of hours of audio and hundreds of videos daily, looking for incidents that impact our users’ safety. After distilling this information, we must determine which users need to receive alerts. To do this at scale, we’ve built AI/ML models for audio analysis, notification delivery, and video moderation using state-of-the-art technology.

• Mobile Video Streaming: Our app ingests high-quality, low-latency video, transcodes it, and redistributes it both within our app and to external media outlets. We tackle the challenges of mobile-first, cellular-first, high-quality live streaming head-on.

• Radio Hardware: We build our own software-defined, radio-based devices to consume all radio dispatch in every major city, whether analog or digital.

About the Role 

• Work in a fast-moving, highly-adaptable environment.

• Design and build systems for scale, modularity, and flexibility – without compromising on high availability, low latency, and scalability.

• Take operational responsibility for the services you build. A strong owner's mindset is essential.

• Collaborate closely with a multidisciplinary team of product managers, designers, and engineers to deliver a consistent real-time experience for our users.

• Maintain rigor in code quality, best practices, and code reviews, while balancing product tradeoffs.

Our Stack

• Mobile: Swift (iOS), Kotlin (Android)

• Web: React.js, TypeScript

• Services: Go for transactional systems; Python for analytical systems

• Datastores: MySQL, PostgreSQL, BigQuery, Memcached, Redis

• Infrastructure: Google Cloud Platform

Requirements

• Proven experience designing and implementing performant APIs on distributed systems.

• Strong knowledge of data design and database systems.

• A track record of demonstrable ownership and technical leadership.

• Experience working with production code using languages such as C++, Go, Java, Python, Scala, etc.

• 5+ years of engineering experience, focusing primarily on backend development

• Bachelor’s Degree in Computer Science or related field, or equivalent practical experience.

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

EEOC & Diversity Statement

Citizen is an equal opportunity employer and is committed to building a team that represents a variety of backgrounds, perspectives, and skills. We believe that diverse teams drive innovation and create better outcomes for the communities we serve. We strongly encourage applications from all individuals, regardless of race, ethnicity, gender identity, sexual orientation, age, disability, veteran status, or any other protected status.

If you don’t meet every requirement in this job description, we encourage you to apply anyway. We value skills, potential, and lived experience as much as direct qualifications.