Senior R Shiny Developer Jobs in Boulder, CO (NOW HIRING)

At Klaviyo, we value the unique backgrounds, experiences and perspectives each Klaviyo (we call ourselves Klaviyos) brings to our workplace each and every day. We believe everyone deserves a fair shot at success and appreciate the experiences each person brings beyond the traditional job requirements. If you're a close but not exact match with the description, we hope you'll still consider applying. Want to learn more about life at Klaviyo? Visit klaviyo.com/careers to see how we empower creators to own their own destiny.
Klaviyo is looking for a Senior Security Engineer to add to our growing Detection and Response (D&R) Team. This is a hands-on technical role that involves building and maintaining secure, reliable, and scalable detection and response systems to enhance our security observability capabilities. This role will also be responsible for participating in full end-to-end detection development and response lifecycle and support with threat response operations. As a Senior Security Engineer, you will have the opportunity to leverage your security and engineering skills to provide thought leadership, solve complex security challenges and ultimately improve Klaviyo's overall security posture.
How you will make a difference:

• Build systems that facilitate security observability for detection and response
• Develop AI-first security systems to automate detection and response operations
• Onboard, normalize and optimize security logging data for large-scale data analysis, detection engineering, deployment of ML models, and efficient querying during incidents.
• Develop high-fidelity rule-based and/or ML-based detections as code
• Respond to security alerts, cyber threats, and security incidents
• Drive end-to-end incident response investigations
• Automate and codify detection and response workflows and processes
• Conduct ad-hoc threat hunts and be an active member of D&R on-call rotations

We'd love to hear from you if you have:

• 5+ years of experience in software, security, and/or data engineering
• Automation-first and AI-first approach for all work performed
• Experience with centralized logging, data lakes, and SIEM solutions
• Familiarity with large-scale data pipelines and data engineering techniques
• Proficient in programming languages to automate / build (e.g., Python, Go or similar)
• Proven experience with git/GitHub and CI/CD automations
• Familiarity with tactics, techniques, and procedures used by threat actors
• Experience being part of detection and response or incident response on-call
• Strong passion for continuous learning and staying updated on evolving technology
• Strong oral and written communication skills
• Team player with a strong, self-managing work ethic

We use Covey as part of our hiring and / or promotional process. For jobs or candidates in NYC, certain features may qualify it as an AEDT. As part of the evaluation process we provide Covey with job requirements and candidate submitted applications. We began using Covey Scout for Inbound on April 3, 2025.
Please see the independent bias audit report covering our use of Covey here
Massachusetts Applicants:It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability.
Our salary range reflects the cost of labor across various U.S. geographic markets. The range displayed below reflects the minimum and maximum target salaries for the position across all our US locations. The base salary offered for this position is determined by several factors, including the applicant's job-related skills, relevant experience, education or training, and work location.
In addition to base salary, our total compensation package may include participation in the company's annual cash bonus plan, variable compensation (OTE) for sales and customer success roles, equity, sign-on payments, and a comprehensive range of health, welfare, and wellbeing benefits based on eligibility.
Your recruiter can provide more details about the specific salary/OTE range for your preferred location during the hiring process.
Base Pay Range For US Locations:
$141,600-$212,400 USD
This role may require up to 10% travel for purposes such as new hire onboarding, client or partner work if applicable, team meetings, and industry events. Travel is coordinated in advance.
Get to Know Klaviyo
We're Klaviyo (pronounced clay-vee-oh). We empower creators to own their destiny by making first-party data accessible and actionable like never before. We see limitless potential for the technology we're developing to nurture personalized experiences in ecommerce and beyond. To reach our goals, we need our own crew of remarkable creators-ambitious and collaborative teammates who stay focused on our north star: delighting our customers. If you're ready to do the best work of your career, where you'll be welcomed as your whole self from day one and supported with generous benefits, we hope you'll join us.
AI fluency at Klaviyo includes responsible use of AI (including privacy, security, bias awareness, and human-in-the-loop). We provide accommodations as needed.
By participating in Klaviyo's interview process, you acknowledge that you have read, understood, and will adhere to our Guidelines for using AI in the Klaviyo interview Process. For more information about how we process your personal data, see our Job Applicant Privacy Notice.
Klaviyo is committed to a policy of equal opportunity and non-discrimination. We do not discriminate on the basis of race, ethnicity, citizenship, national origin, color, religion or religious creed, age, sex (including pregnancy), gender identity, sexual orientation, physical or mental disability, veteran or active military status, marital status, criminal record, genetics, retaliation, sexual harassment or any other characteristic protected by applicable law.
IMPORTANT NOTICE: Our company takes the security and privacy of job applicants very seriously. We will never ask for payment, bank details, or personal financial information as part of the application process. All our legitimate job postings can be found on our official career site. Please be cautious of job offers that come from non-company email addresses (@klaviyo.com), instant messaging platforms, or unsolicited calls.
By clicking "Submit Application" you consent to Klaviyo processing your Personal Data in accordance with our Job Applicant Privacy Notice. If you do not wish for Klaviyo to process your Personal Data, please do not submit an application. You can find our Job Applicant Privacy Notice here and here (FR).