Sr. Staff Machine Learning Engineer


 184k - 315k
 United States  (San Francisco)
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Hiring Ranges:

Tier 1 US Locations: $217,000 USD - $315,000 USD

Tier 2 US Locations: $199,000 USD - $290,000 USD

Tier 3 US Locations: $184,000 USD - $268,000 USD


Why Mozilla?

Mozilla Corporation is the non-profit-backed technology company behind pioneering brands like Firefox, the privacy-minded web browser, and Pocket, a service for keeping up with the best articles online. More than 225 million people around the world use its products each month.

Along with 60,000+ volunteer contributors and collaborators all over the world, Mozilla Corporation’s staff are driven by our mission to ensure the internet is a global public resource, open and accessible to all. We design, build and distribute open-source software that enables people to enjoy the internet on their terms. 

About this team and role:

Fakespot is now part of Mozilla, where our mission to bring trust and transparency back to the eCommerce space is now aligned with ensuring the Internet is a global resource, open and accessible to all. Fakespot leverages machine learning, and other state-of-the-art technologies to detect spurious product reviews and vendors so consumers can make informed purchasing decisions based on real feedback by real people. Fakespot also facilitates the shoppers’ decision making process by utilizing language models to interactively summarize and highlight product features.  

At the Fakespot team, you will have the opportunity to play a crucial role in bringing trustworthy tools to millions of Firefox and Fakespot users.  By joining our team, you will be at the forefront of ethical and responsible AI, and contribute to a trustworthy Internet. 

What you’ll do: 

  • Lead analytics projects, designing, developing, and deploying state-of-the-art machine learning models in line with business interests, particularly those related to enhancing the online shopping experience of our users 

  • Harness your expertise in acquiring and processing large-scale and complex datasets from diverse sources, utilizing it for analysis and modeling by the team 

  • Implement robust validation and testing procedures to ensure the developed models' generalizability and reliability

  • Continuously monitor and optimize deployed models for performance and efficiency, and conduct troubleshooting when necessary

  • Collaborate with other members in the data science team to brainstorm ideas, and search for optimal solutions  

  • Work closely with the engineering, product management, and product design teams to deliver high-quality features and solutions

  • Be involved in the full lifecycle of machine learning models, from development to deployment and monitoring, to ensure the models are effectively integrated into the production environment and continually optimized for performance

  • Proactively stay abreast of the latest advancements in machine learning, natural language processing, and related fields to ensure our methodologies remain innovative and relevant

  • Lead and mentor junior machine learning engineers, providing hands-on guidance where needed


What you’ll bring: 

  • A bachelor’s degree in Statistics, Computer Science, related technical field, or equivalent practical experience

  • A minimum of 5 years of experience in a quantitative role, ideally as a machine learning engineer or a data scientist

  • Extensive knowledge of and experience with analyzing large-scale dataset utilizing statistical and machine learning tools

  • Proficiency in a data query language (e.g. SQL), and a programming language (e.g. Python)    

  • Extensive experience with deep learning frameworks (e.g. Pytorch, Tensorflow, Jax), and deep learning architectures (e.g. Transformer, RNN)

  • Demonstrable experience with the full lifecycle of machine learning models - from development to deployment and monitoring

  • Being goal-oriented with an independent problem solver with minimal supervision

  • Enjoyment for taking ownership while engaging in collaborative efforts to fully comprehend the needs of other teammates

  • Being an excellent team player with a proven ability to work effectively in cross-functional teams, showing a high degree of collaboration, flexibility, and respect for diverse perspectives

  • Commit to our values:

    • Welcoming differences

    • Being relationship-minded

    • Practicing responsible participation

    • Having grit


Bonus Points For…

  • An advanced degree (master or PhD) in a quantitative field

  • Over 7 years of experience as a machine learning engineer or in a similar role

  • A deep understanding of deep learning, reinforcement learning, and natural language processing

  • Experience with cloud platforms such as AWS, Google Cloud, or Azure, and familiarity with related machine learning services

  • Experience with big data technologies like Hadoop, Spark, or similar

  • Demonstrated prior experience with large language models, and generative AI 

  • Experience with design of experiments, survey design, and large-scale AB testing

  • Contributions to open-source projects in the machine learning community

  • Enthusiasm in bringing trust to the e-commerce platforms and beyond

What you’ll get:

  • Generous performance-based bonus plans to all regular employees - we share in our success as one team

  • Rich medical, dental, and vision coverage

  • Generous retirement contributions with 100% immediate vesting (regardless of whether you contribute)

  • Quarterly all-company wellness days where everyone takes a pause together

  • Country specific holidays plus a day off for your birthday

  • One-time home office stipend

  • Annual professional development budget

  • Quarterly well-being stipend

  • Considerable paid parental leave

  • Employee referral bonus program

  • Other benefits (life/AD&D, disability, EAP, etc. - varies by country)


About Mozilla 

Mozilla exists to ensure that the internet is a public resource accessible to all because we believe that open and free is better than closed and controlled. When you work at Mozilla, you give yourself a chance to make a difference in the lives of web users everywhere. And you give us a chance to make a difference in your life every single day. Join us to work on the web as the platform and help create more opportunity and innovation for everyone online. 

Commitment to diversity, equity and inclusion

Mozilla believes in the value of diverse creative practices and forms of knowledge, and knows diversity, equity and inclusion are crucial to and enrich the company’s core mission. We encourage applications from everyone, including members of all equity-seeking communities, such as (but not limited to) women, racialized and Indigenous persons, persons with disabilities, persons of all sexual orientations, gender identities and expressions.


We will ensure that qualified individuals with disabilities are provided reasonable accommodations to participate in the job application or interview process, to perform essential job functions, and to receive other benefits and privileges of employment, as appropriate. Please contact us at to request accommodation.


We are an equal opportunity employer. We do not discriminate on the basis of race (including hairstyle and texture), religion (including religious grooming and dress practices), gender, gender identity, gender expression, color, national origin, pregnancy, ancestry, domestic partner status, disability, sexual orientation, age, genetic predisposition, medical condition, marital status, citizenship status, military or veteran status, or any other basis covered by applicable laws. Mozilla will not tolerate discrimination or harassment based on any of these characteristics or any other unlawful behavior, conduct, or purpose.

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