Staff Application Security Engineer

About the role

Meet Upside:

We created Upside to transform brick-and-mortar commerce. Our technology uses the sophistication of online retail—profit measurement, attribution, and incrementality—to provide users with more value on their everyday purchases and brick-and-mortar businesses with new, profitable customers. We’ve helped millions of users earn 2 to 3 times more cashback than any other product, and hundreds of thousands of brick-and-mortar businesses earn measurable profit. Billions of dollars in commerce run through the Upside platform every year, and that value goes directly back to our retailer partners, the consumers they serve, and important sustainability initiatives.

The Impact You'll Make:

You'll report to the Product Security Manager and work closely with our Cloud Security and Engineering teams to scale secure software delivery across Upside. This role owns our application security program, reducing real risk across mobile, web, and cloud systems by driving remediation, building engineering guardrails, and creating security guidance that developers actually use.

You'll also work both sides of AI: we use it to do security work, and we secure the AI systems Upside is shipping.

- Own Upside's application security program, the standards, the vulnerability management pipeline, and the guardrails that stop entire classes of defects from coming back

- Drive vulnerability management outcomes by triaging and tuning findings from scanning, code review, and our annual penetration test, then partnering with engineering teams to get fixes shipped and verified

- Lead application security reviews and threat models for high-impact work across mobile, web, backend, and AI systems, and document risk decisions with clear mitigation plans

- Extend the AI automation that handles our finding volume: triage, prioritization with service context, and remediation guidance engineers can act on

- Build guardrails that scale beyond our team; repository baselines, required checks in GitHub, secure-by-default patterns for AWS workloads, reusable templates, and a security champions program

What You'll Bring:

- 6+ years in application or product security, or equivalent depth in secure software engineering with meaningful application security ownership

- Strong Python code review skills. You can open a Lambda, understand what it does, and explain the defect to the engineer who wrote it

- A track record of shipping security improvements that reduced real risk, including fixes you drove to completion with teams you did not own

- Experience with threat modeling and secure design review, engaging with designs before they ship

- Practical, everyday use of AI in your security work

- Working knowledge of our stack: AWS security (Lambda, API Gateway, IAM least privilege, secrets handling) and CI/CD security in GitHub Actions

Tools We Use:

- GitHub: Actions, Advanced Security, Copilot