Engineer, Machine Learning

| Remote
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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. 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 tens of millions in VC funding.

Our Challenges
  • Scaling: We have one of the fastest-growing organic user bases in NYC, and have expanded to multiple other cities. We are focused on the nationwide launch and the need to support that scale. A Citizen international launch will follow.
  • Bursting: We designed our infrastructure to scale without notice in case of a spontaneous incident where we need to inform our entire user base. On significant events, we see over a million simultaneously connected clients and their associated live streams. The 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 will ingest high-quality video at low-latency, transcode, and redistribute 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 - languages and technologies we use and teach
    • Mobile: Swift (iOS), Kotlin (Android)
    • Web: React.js, TypeScript
    • Services: Go for transactional systems; Python for analytical systems
    • Datastores: Cassandra, MySQL, Redis, Google PubSub
    • Infrastructure: Kubernetes on Google Cloud
Role Description
    • Develop a deep neural network for audio flagging to improve operational efficiency
    • Develop a Churn model to help determine when a customer is about to churn from Citizen 
    • Help determine how users are targeted for notifications
    • Design feed ranking algorithms to improve business objects, including: Shares, Sign-ups, etc.
    • Develop models for moderating video content (TV/Games, No content, etc.) 
    • Select best thumbnails from a list of videos and ranking videos within an incident
Preferred Qualifications
    • Computer Science degree or Machine Learning related degree; or equivalent work experience in the field
    • Good theoretical grounding in core Machine Learning concepts and techniques
    • Ability to reason about and grasp the intuition behind fundamental principles of Linear Algebra, Statistics, Probability
    • Experience with a number of ML techniques and frameworks, e.g. data discretization, normalization, sampling, linear regression, decision trees, SVMs, deep neural networks, etc
    • Familiarity with one or more DL software frameworks such as TensorFlow, PyTorch
    • 3+ years experience leading and delivering effective ML solutions for large scale production use cases

Citizen offers a competitive benefits package including medical, dental, vision, flexible spending accounts, unlimited PTO, company holidays, stock options, commuter benefits, lunch daily, weekly team dinners, regular team outings, guest speakers, and lots more! 

 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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Technology we use

  • Engineering
    • GolangLanguages
    • JavascriptLanguages
    • SwiftLanguages
    • GoLanguages
    • Node.jsLanguages
    • ReactLibraries
    • Node.jsFrameworks
    • MySQLDatabases
    • RedisDatabases
    • KafkaDatabases

Location

Financial District, New York, NY 10004

An Insider's view of Citizen

What's something quirky about your company?

Citizen operates 24/7, because we’re dedicated to keeping you safe and informed around the clock. We never know when a firefighter might be called to rescue a cat from a tree, or when a wildfire might break out and quickly spread. Something unexpected is always happening somewhere.

Sam

Overnight Operations Manager

What projects are you most excited about?

Building new tools to help everyone keep the people, places, and things they love safe, and to provide unparalleled access to help in emergencies.

Cissy

Product Manager, Safety Tools

How has your career grown since starting at the company?

I first joined Citizen to use technology to enhance my job as a violence interrupter, trying to stop shootings before they happen. Two years later, I am an engineer who builds hardware to enhance every violence interrupter’s job in the nation.

Prince

Hardware Engineer

What are Citizen Perks + Benefits

Citizen Benefits Overview

Citizen offers a competitive benefits package including medical, dental, vision, flexible spending accounts, paid time off, company holidays, stock option plan, commuter benefits, remote-friendly policy, and various wellness perks.

Culture
Volunteer in local community
Partners with Nonprofits
Friends outside of work
Eat lunch together
Intracompany committees
Culture Committee, Book Club, Speaker Series
Daily stand up
Open door policy
Team owned deliverables
Team based strategic planning
Group brainstorming sessions
Open office floor plan
Diversity
Unconscious bias training
Mean gender pay gap below 10%
Hiring Practices that Promote Diversity
Health Insurance & Wellness Benefits
Flexible Spending Account (FSA)
Disability Insurance
Dental Benefits
Vision Benefits
Health Insurance Benefits
Life Insurance
Wellness Programs
Mental Health Benefits
Retirement & Stock Options Benefits
401(K)
Company Equity
Child Care & Parental Leave Benefits
Generous Parental Leave
Flexible Work Schedule
Remote Work Program
Family Medical Leave
Vacation & Time Off Benefits
Unlimited Vacation Policy
Generous PTO
Paid Holidays
Paid Sick Days
Perks & Discounts
Beer on Tap
Casual Dress
Commuter Benefits
Company Outings
Free Daily Meals
Stocked Kitchen
Happy Hours
Pet Friendly
Relocation Assistance
Fitness Subsidies
Professional Development Benefits
Job Training & Conferences
Diversity Program
Cross functional training encouraged
Promote from within
Online course subscriptions available
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