Senior Security Engineer

400M+ downloads. 75M+ monthly users. A decade of building – and we’re still accelerating.

Flo is the world’s #1 health app on a mission to build a better future for female health. Backed by a $200M investment led by General Atlantic, we became the first product of our kind to reach a $1B valuation in 2024 – and we’re not slowing down.

With 6M paid subscribers and the highest-rated experience in the App Store’s health category, we’ve spent 10 years earning trust at scale. Now, we’re building the next generation of digital health – AI-powered, privacy-first, clinically backed – to help our users know their body better.

The job

Your role as the Security Engineer will be pivotal in supporting Flo Health’s overall security posture. Working alongside our small but powerful Security team, you will help protect our applications and infrastructure by managing vulnerabilities, responding to incidents, and implementing security measures at scale. You’ll also contribute to developing custom tooling and embedding security best practices into our product lifecycle to ensure we stay ahead of emerging threats.

What you will do:

• Developing regular touchpoints with key stakeholders.
• Manage Vulnerabilities: Triage newly discovered vulnerabilities, investigate potential risks, verify that fixes are effective, and drive remediation efforts across teams.
• Implement Security Measures: Support teams by configuring WAF rules, setting rate limits, and deploying additional controls to protect our environment.
• Develop Custom Security Tooling: Contribute to the creation and maintenance of in-house tools that enhance our security capabilities and automation.
• Product Security Support: Assist in security assessments, threat modeling, and penetration testing, working closely with the Product Security team.
• Secure Development Lifecycle: Help implement and improve security gates within the SDLC.
• Adapt & Collaborate: Be prepared to dive into any emerging security challenges. We’re a small team with big responsibilities, and flexibility is key.
• Investigate and triage security alerts, manage security incidents.
• Gather, curate and communicate threat intelligence.
• Support and advise business stakeholders in relation to cyber security issues.
• Generate reports for both technical and non-technical staff and stakeholders.

What you bring:

• At least 7 years of experience in the information security field.
• Hands-on experience with AWS (or similar cloud platforms) and Cloudflare.
• Infrastructure as Code: Proficiency with Terraform or similar IaC tools.
• Vulnerability Knowledge: Solid understanding of common vulnerability classes and the OWASP Top 10.
• Coding & Scripting: Proficient in reading code (e.g., Python, Scala) and using Git for version control of code and configuration changes.
• Familiarity with iOS or Android security.
• Experience of industry-standard SIEM and vulnerability scanning tools.

Nice to have:

• Experience of supporting audits such as ISO27001.
• Experience of working with security risk management frameworks such as ISO31000.
• Knowledge of security control frameworks such as CIS, NIST800-53 and ISO27001.

How we work

We’re a mission-led, product-driven team. We move fast, stay focused and take ownership – from brief to build to impact. Debate is encouraged. Decisions are shared. We care about craft, ship with purpose, and always raise the bar.

You’ll be working with people who take their work seriously, not themselves. It takes commitment, resilience, and the drive to keep going when things get tough. Because better health outcomes are worth it.

What you\’ll get

We support impact with meaningful reward. Here’s what that looks like:

• Competitive salary and annual reviews
• Opportunity to participate in Flo’s performance incentive scheme
• Paid holiday, sick leave, and female health leave
• Enhanced parental leave and pay for maternity, paternity, same-sex and adoptive parents
• Accelerated professional growth through world-changing work and learning support
• Flexible office + home working, up to 2 months a year working abroad
• 5-week fully paid sabbatical at 5-year Floversary
• Flo Premium for friends & family, plus more health, pension and wellbeing perks

Diversity, equity and inclusion

Our strength is in our differences. At Flo, hiring is based on merit, skill and what you bring to the role – nothing else. We’re proud to be an equal opportunity employer, and we welcome applicants from all backgrounds, communities and identities. Read our privacy notice for job applicants .

Apply for this job

*

indicates a required field

First Name *

Last Name *

Preferred First Name

Email *

Phone

Resume/CV

Enter manually

Accepted file types: pdf, doc, docx, txt, rtf

Enter manually

Accepted file types: pdf, doc, docx, txt, rtf

LinkedIn Profile

Website

We are considering for this vacancy candidates who are based in the UK and are eligible to work there. Could you confirm that this requirement suits you? * Select…

Our team in London like to gather in the office from time to time to collaborate. Would you be willing to travel into the office twice a week to meet with the team? * Select…

By applying for the above role, you confirm that you have reviewed our privacy notice for job applicants: * Select…

Flo Health can contact me about job opportunities for up to 3 years * Select…

Voluntary Self-Identification

For government reporting purposes, we ask candidates to respond to the below self-identification survey.Completion of the form is entirely voluntary. Whatever your decision, it will not be considered in the hiringprocess or thereafter. Any information that you do provide will be recorded and maintained in aconfidential file.

As set forth in Flo Health’s Equal Employment Opportunity policy,we do not discriminate on the basis of any protected group status under any applicable law.

If you believe you belong to any of the categories of protected veterans listed below, please indicate by making the appropriate selection.As a government contractor subject to the Vietnam Era Veterans Readjustment Assistance Act (VEVRAA), we request this information in order to measurethe effectiveness of the outreach and positive recruitment efforts we undertake pursuant to VEVRAA. Classification of protected categoriesis as follows:

A \”disabled veteran\” is one of the following: a veteran of the U.S. military, ground, naval or air service who is entitled to compensation (or who but for the receipt of military retired pay would be entitled to compensation) under laws administered by the Secretary of Veterans Affairs; or a person who was discharged or released from active duty because of a service-connected disability.

A \”recently separated veteran\” means any veteran during the three-year period beginning on the date of such veteran\’s discharge or release from active duty in the U.S. military, ground, naval, or air service.

An \”active duty wartime or campaign badge veteran\” means a veteran who served on active duty in the U.S. military, ground, naval or air service during a war, or in a campaign or expedition for which a campaign badge has been authorized under the laws administered by the Department of Defense.

An \”Armed forces service medal veteran\” means a veteran who, while serving on active duty in the U.S. military, ground, naval or air service, participated in a United States military operation for which an Armed Forces service medal was awarded pursuant to Executive Order 12985.

Select…

Voluntary Self-Identification of Disability

Form CC-305

Page 1 of 1

OMB Control Number 1250-0005

Expires 04/30/2026

Voluntary Self-Identification of Disability

Form CC-305 Page 1 of 1 OMB Control Number 1250-0005 Expires 04/30/2026
Why are you being asked to complete this form?

We are a federal contractor or subcontractor. The law requires us to provide equal employment opportunity to qualified people with disabilities. We have a goal of having at least 7% of our workers as people with disabilities. The law says we must measure our progress towards this goal. To do this, we must ask applicants and employees if they have a disability or have ever had one. People can become disabled, so we need to ask this question at least every five years.

Completing this form is voluntary, and we hope that you will choose to do so. Your answer is confidential. No one who makes hiring decisions will see it. Your decision to complete the form and your answer will not harm you in any way. If you want to learn more about the law or this form, visit the U.S. Department of Labor’s Office of Federal Contract Compliance Programs (OFCCP) website at .

How do you know if you have a disability?

A disability is a condition that substantially limits one or more of your “major life activities.” If you have or have ever had such a condition, you are a person with a disability. Disabilities include, but are not limited to:

• Alcohol or other substance use disorder (not currently using drugs illegally)
• Autoimmune disorder, for example, lupus, fibromyalgia, rheumatoid arthritis, HIV/AIDS
• Blind or low vision
• Cancer (past or present)
• Cardiovascular or heart disease
• Celiac disease
• Cerebral palsy
• Deaf or serious difficulty hearing
• Diabetes
• Disfigurement, for example, disfigurement caused by burns, wounds, accidents, or congenital disorders
• Epilepsy or other seizure disorder
• Gastrointestinal disorders, for example, Crohn\’s Disease, irritable bowel syndrome
• Intellectual or developmental disability
• Mental health conditions, for example, depression, bipolar disorder, anxiety disorder, schizophrenia, PTSD
• Missing limbs or partially missing limbs
• Mobility impairment, benefiting from the use of a wheelchair, scooter, walker, leg brace(s) and/or other supports
• Nervous system condition, for example, migraine headaches, Parkinson’s disease, multiple sclerosis (MS)
• Neurodivergence, for example, attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder, dyslexia, dyspraxia, other learning disabilities
• Partial or complete paralysis (any cause)
• Pulmonary or respiratory conditions, for example, tuberculosis, asthma, emphysema
• Short stature (dwarfism)
• Traumatic brain injury

Disability Status Select…

PUBLIC BURDEN STATEMENT: According to the Paperwork Reduction Act of 1995 no persons are required to respond to a collection of information unless such collection displays a valid OMB control number. This survey should take about 5 minutes to complete.

#J-18808-Ljbffr