Staff Software Engineer - Site Defense

United States

Remote

Who this role is best for

Geared toward candidates with experience in high-scale distributed systems and a background in network security, comfortable with real-time traffic mitigation and collaboration across teams. The role is remote in the U.S. and involves end-to-end ownership of critical infrastructure.

Best fit for

Candidates with 7+ years of experience in high-throughput, low-latency distributed systems and a track record in DDoS mitigation
— “7+ years of experience building and operating high throughput and low latency production distributed systems.”
Individuals who have worked with networking protocols and infrastructure layers like CDNs and proxies
— “Experience with networking fundamentals (HTTP, TLS, TCP/IP, proxies, CDNs, load balancing).”
Candidates who have experience mentoring junior engineers and working in cross-functional teams
— “Mentor junior engineers in their professional growth.”

Things to consider

The role involves being on-call and owning services end-to-end, which demands high availability and operational responsibility.
— “Own services end-to-end, including design, implementation, on-call, and operational excellence.”
The position may require participation in recorded interviews, which could be a concern for privacy-sensitive candidates.
— “In select roles and locations, the interviews will be recorded, transcribed and summarized by artificial intelligence (AI).”

How to stand out

Highlight your experience in designing and operating systems that detect and mitigate malicious traffic in real time.
— “Build systems to detect, score, and mitigate malicious traffic in real time at per-request and per-user granularity.”
Emphasize your background in machine learning, particularly in real-time inference or feature pipelines.
— “Contribute to the team’s ML-at-Ingress initiatives, including experimenting with models for traffic classification, bot detection, and anomaly detection.”
Showcase your ability to balance multiple priorities, such as security, performance, and user experience.
— “Partner closely within Infrastructure and with Security, and internal Safety teams to balance security, performance, and user experience.”
Demonstrate your experience with WAFs, bot management, and abuse prevention systems in your resume and interview responses.
— “Experience with DDoS mitigation, WAFs, bot management, or abuse prevention systems.”
Include specific examples of your work with CDNs, edge infrastructure, or internal network layers.
— “Analyze, develop and evolve ingress-level defenses across CDN, edge, and internal infrastructure layers.”

Pace · Fast PacedCollaboration · HighAutonomy · MediumDecision Impact · Team

Derived from job-description analysis by Serendipath's career intelligence engine.

What success looks like

Design and build high-scale, low-latency systems
Analyze and develop ingress-level defenses
Build systems for real-time traffic detection and mitigation
Contribute to ML-at-Ingress initiatives

Typical background

7+ years of experience in backend software engineeringExperience with DDoS mitigation and abuse prevention systems

Skills & requirements

Required

PythonGoRustJavaC++Distributed SystemsNetworkingSecurityMachine Learning

Preferred

RecaptchaDatadomeTurnstileFingerprintjsThumbmarkjs

Stack & domain

PythonGoRustJavaC++Ddos MitigationWafsBot ManagementAbuse Prevention SystemsNetworking FundamentalsHTTPTLSTcp/ipProxiesCdnsLoad BalancingML SystemsReal-time InferenceFeature PipelinesCommunicationNetwork SecurityApplied Machine Learning

About the role

Original posting from Reddit via Greenhouse

Reddit is a community of communities. It’s built on shared interests, passion, and trust, and is home to the most open and authentic conversations on the internet. Every day, Reddit users submit, vote, and comment on the topics they care most about. With 100,000+ active communities and approximately 130 million daily active unique visitors, Reddit is one of the internet’s largest sources of information. For more information, visit www.redditinc.com.
Reddit's Transport and Site Defense teams build and operate foundational infrastructure behind one of the largest sites in the world. These teams own how requests enter Reddit, how services discover and talk to each other, how traffic moves across clusters and clouds, and how Reddit protects itself from DDoS attacks, scrapers, bots, and other undesired traffic.
We are looking for a Staff Software Engineer to join the Site Defense team within Reddit’s Infrastructure organization. Site Defense is responsible for protecting Reddit at internet scale—serving as the first line of defense against DDoS attacks, automated abuse, large-scale scraping, and other network-level threats. This is a high impact role that sits at the intersection of distributed systems, networking, security, and applied machine learning. You will design and own the critical infrastructure that safeguards Reddit’s data from large scale attacks.
You will:
Design, build, and operate high-scale, low-latency systems that protect Reddit from DDoS attacks, bots, and automated abuse.
Analyze, develop and evolve ingress-level defenses across CDN, edge, and internal infrastructure layers.
Build systems to detect, score, and mitigate malicious traffic in real time at per-request and per-user granularity
Partner closely within Infrastructure and with Security, and internal Safety teams to balance security, performance, and user experience
Mentor junior engineers in their professional growth.
Contribute to the team’s ML-at-Ingress initiatives, including experimenting with models for traffic classification, bot detection, and anomaly detection
Own services end-to-end, including design, implementation, on-call, and operational excellence
Participate in incident response and post-incident analysis for large-scale network or abuse events
You have:
7+ years of experience building and operating high throughput and low latency production distributed systems.
Software development experience in one or more general purpose programming languages; Python, Go, Rust, Java, C++.
Excellent communication skills to collaborate with a service-oriented team and company.
Experience with DDoS mitigation, WAFs, bot management, or abuse prevention systems.
Experience with networking fundamentals (HTTP, TLS, TCP/IP, proxies, CDNs, load balancing).
Nice to have:
Experience with anti-abuse frameworks and bot scores (ReCaptcha, Datadome, Turnstile)
Experience with browser fingerprinting frameworks (fingerprintJS, ThumbmarkJS)
Familiarity with ML systems in production, especially real-time inference or feature pipelines.
Benefits:
Comprehensive Healthcare Benefits and Income Replacement Programs
401k with Employer Match
Global Benefit programs that fit your lifestyle, from workspace to professional development to caregiving support
Family Planning Support
Gender-Affirming Care
Mental Health & Coaching Benefits
Flexible Vacation & Paid Volunteer Time Off
Generous Paid Parental Leave
#LI-Remote
Pay Transparency:
This job posting may span more than one career level.
In addition to base salary, this job is eligible to receive equity in the form of restricted stock units, and depending on the position offered, it may also be eligible to receive a commission. Additionally, Reddit offers a wide range of benefits to U.S.-based employees, including medical, dental, and vision insurance, 401(k) program with employer match, generous time off for vacation, and parental leave. To learn more, please visit https://www.redditinc.com/careers/.
To provide greater transparency to candidates, we share base salary ranges for all US-based job postings regardless of state. We set standard base pay ranges for all roles based on function, level, and country location, benchmarked against similar stage growth companies. Final offer amounts are determined by multiple factors including, skills, depth of work experience and relevant licenses/credentials, and may vary from the amounts listed below.
The base salary range for this position is:$217,000—$303,900 USDIn select roles and locations, the interviews will be recorded, transcribed and summarized by artificial intelligence (AI). You will have the opportunity to opt out of recording, transcription and summarization prior to any scheduled interviews.
During the interview, we will collect the following categories of personal information: Identifiers, Professional and Employment-Related Information, Sensory Information (audio/video recording), and any other categories of personal information you choose to share with us. We will use this information to evaluate your application for employment or an independent contractor role, as applicable. We will not sell your personal information or disclose it to any third party for their marketing purposes. We will delete any recording of your interview promptly after making a hiring decision. For more information about how we will handle your personal information, including our retention of it, please refer to our Candidate Privacy Policy for Potential Employees and Contractors.
Reddit is proud to be an equal opportunity employer, and is committed to building a workforce representative of the diverse communities we serve. Reddit is committed to providing reasonable accommodations for qualified individuals with disabilities and disabled veterans in our job application procedures. If, due to a disability, you need an accommodation during the interview process, please let your recruiter know.

Source: Reddit careers (Greenhouse)