Software Engineer, Backend/Applied ML (Safety & Integrity)

Character.AI, Redwood City, CA

The role

We’re looking for a talented and creative Software Engineer to join our Safety Engineering team at Character.AI http://Character.AI! In this role, you will be at the forefront of designing, developing, and scaling robust backend systems and leveraging applied machine learning to tackle critical integrity and safety challenges. You will be architecting and implementing innovative solutions in a key role in addressing the unique safety challenges that come with human-to-AI interaction—bringing your technical expertise to the table as we define industry best practices in this emerging space.

All jobs

Software Engineer, Backend/Applied ML (Safety & Integrity)

Character.AI, Redwood City, CA

Posted pay

$150K–$300K

a year

Compared with similar jobs

This base pay is near the median for ML and AI engineering jobs in the Bay Area with no level in the job title.

Median: $220K a year
Other jobs in the group: 697

We compare the middle of each posted range. This is base pay as posted. The group does not include this job.

Location: Redwood City, CA
Work type: Hybrid
Level: Not given
Experience: 8+ years
Skills in the job text: Python
Java
Go
C++
A/B testing
Posted: Jan 7, 2026
Last check: 57 min ago
Job type: ML / AI engineering

Apply on the Character.AI site Sign in to save

The Character.AI site opens in a new tab.

Character.AI

Open tech jobs: 13
With posted pay: 100%
Median posted base: $200K–$300K

About Character.AI: funding, hiring and pay

Character.AI

About Character.AI: funding, hiring and pay

Company facts

Money raised: $150MSum of funding rounds on record
Newest round: Series AMar 23, 2023

Funding records can have errors and can be missing. The company page has the links.

Interview questions

No one has reported an interview at Character.AI yet. Did you interview there? Add the questions.

Check my fit

Compare your résumé with this job. See where you match, what is missing and which lines to change.

The role

What you will do

Architect & Build: Design, develop, and maintain highly scalable, resilient, and performant backend systems that power our integrity and safety features.
Lead Complex Solutions: Lead the technical design and implementation of sophisticated backend solutions for detecting, preventing, and mitigating a wide array of integrity risks. This includes traditional issues (e.g., content classification, spam, etc.) as well as emerging threats related to Generative AI (e.g., misuse of generative models, generation of harmful or biased content, etc).
Apply Machine Learning: Conceptualize, develop, deploy, and iterate on machine learning models and algorithms to address complex integrity challenges. This includes areas like content classification (including AI-generated content), anomaly detection, risk scoring, behavior analysis, and developing safeguards for Generative AI systems (e.g., robust content filtering, bias mitigation techniques, and output monitoring).
Cross-Functional Collaboration: Work closely with product managers, data scientists, AI researchers, security teams, and operations to define requirements, design innovative solutions, and deliver impactful integrity systems, especially for Generative AI products.
Technical Strategy & Roadmap: Drive the long-term technical vision and roadmap for backend integrity systems and applied ML capabilities, with a keen eye on addressing Generative AI safety concerns with an alignment with company objectives.
Mentorship & Leadership: Provide technical guidance and mentorship to other engineers on the team and across the organization, fostering a culture of engineering excellence.
Champion Best Practices: Advocate for and implement best practices in software engineering, distributed systems design, data engineering, and the full lifecycle of ML model development, including specific considerations for the safety and ethics of Generative AI.
System Optimization: Continuously analyze and improve the performance, scalability, reliability, and cost-effectiveness of existing integrity platforms and ML models.
Stay Current: Keep abreast of emerging threats, new technologies, and advancements in backend engineering, distributed systems, the application of machine learning to trust and safety, and the evolving landscape of Generative AI safety research and mitigation techniques.

Software Engineer, Backend/Applied ML (Safety & Integrity)

The role

Software Engineer, Backend/Applied ML (Safety & Integrity)

The role

What you will do

What you need

You will be a great fit if

About Character.AI

Similar jobs at other companies

Staff AI Engineer

Software Engineer, AI Safety

Senior Software Engineer (Safety)

Senior Machine Learning Engineer (Safety)

Senior AI Engineer, AI Safety

Machine Learning Engineer, Safety

Interview questions

Company facts

Character.AI

Compared with similar jobs