Security Engineer - AppSec

Rain Xyz; New York (NY); Hybrid; USD 140,000 - 210,000; Full time

Benefits offered by this job

Unlimited time off

Flexible working (office or remote)

Health, dental, vision coverage (US)

401(k) with company match

Equity options

Wellness stipend

Job summary

Rain is seeking an application security expert to own the non-chain security findings and drive fixes across backend services, APIs, cloud, and edge that move real money. You’ll collaborate with engineers to determine what is real, how severe it is, and what must be fixed before launch.

You’ll lead with engineers on risk assessment, write clear tickets, and strengthen our security posture with automated checks and robust edge protections.

Qualifications

• 4+ years in application security, product security, or security-minded backend engineering.
• Ability to read unfamiliar codebases (TypeScript/Node.js) and identify real bugs.
• Hands-on cloud security experience (ideally GCP), Terraform, and edge defenses.
• Experience with threat models or architecture reviews and tool evaluations.

Responsibilities

• Review red team findings, reproduce, cut false positives, set severity, and write actionable tickets.
• Harden backend services and APIs, especially money-moving paths, and implement fixes.
• Own edge defenses: DDoS protection, rate limiting, WAF rules, and abuse controls.
• Write secure configuration baselines for cloud, code, and SaaS, and automate checks.
• Grow the security gate to block more bugs before merge and perform architecture reviews.
• Identify and test security tools, and decide buy/adopt/build options.

Skills

Application security

Cloud security (GCP)

Threat modeling

Codebase review (TypeScript/Node.js)

Tools

Terraform

WAFs

Job description

About the Company

Rain is the global stablecoin payments platform for enterprises, neobanks, platforms, developers, and AI agents. Our technology allows partners to move, store, and use stablecoins instantly and compliantly through global payment cards, rewards, on/offramps, wallets, and cross-border rails. As both a Visa and Mastercard Principal Member, Rain issues cards that work at more than 175 million merchant locations in over 220 countries and territories. Built natively for stablecoins and trusted by more than 100 organizations worldwide, Rain delivers secure, scalable infrastructure that makes money move freely and instantly around the world.You will have the opportunity to deliver massive impact at a hypergrowth company backed by some of the top investors in fintech, crypto, and SaaS. In January 2026, we closed a $250M Series C led by ICONIQ, valuing Rain at $1.95B, with Sapphire Ventures, Dragonfly, Bessemer Venture Partners, Galaxy Ventures, FirstMark, Lightspeed, Norwest, and Endeavor Catalyst also participating. If you're curious, bold, and excited to help shape a borderless financial future, we'd love to talk.

Our Ethos

We believe in an open and flat structure. You will be able to grow into the role that most aligns with your goals. Our team members at all levels have the freedom to explore ideas and impact the roadmap and vision of our company.

About the Team

Security Engineering is a small team that answers one question: was it built right? We run our own AI-driven red team against Rain's code and cloud, gate pull requests before they merge, and write the baselines that say how every system should be configured. Our blockchain work is covered. This role owns everything else: the backend services, APIs, cloud, and edge that move real money for real customers.We work closely with Security Operations: we give them high-quality findings to coordinate fixes for, and clear configuration rules they can build detections on.

About the Team

Security Engineering makes sure Rain is built right. We run our own AI-driven red team against our code and cloud, gate pull requests before they merge, and set the baselines for how every system is configured. This role owns everything outside blockchain: the backend services, APIs, cloud, and edge that move real money. We give Security Operations high-quality findings to coordinate fixes for, and clear configuration rules to build detections on.

About the Role

You'll be Rain's application security expert and the quality bar for every non-chain finding we produce. The calls are yours: what's real, how bad it is, and what has to be fixed before launch. You'll hold the line with engineers when it matters, and make the case so they agree, not just comply.

What You'll Do

Review red team findings before they reach engineers: reproduce them, cut false positives, set severity, and write tickets clear enough to fix without a meeting. Improve the scoring that grades them. Harden our backend services and APIs, especially the money-moving paths. You'll often write the fix yourself. Own edge defenses: DDoS protection, rate limiting, WAF rules, and abuse controls. Write secure configuration baselines for our cloud, code, and SaaS, and turn them into automated checks. Grow our PR security gate so more bugs are blocked before merge. Own attack surface coverage, and run architecture reviews on new and high-risk systems. Find, test, and pick the best security tools, whether we buy, adopt, or build.

What We're Looking For

4+ years in application security, product security, or security-minded backend engineeringYou've owned security decisions. You can tell a senior engineer their design needs to change and keep a good working relationshipYou can read an unfamiliar codebase (TypeScript/Node.js) and find the bug that matters, and you know a scary-sounding finding from a real oneHands-on cloud security (ideally GCP), Terraform, and edge defenses like WAFs and rate limitingExperience with threat models or architecture reviews. You've run tool bake-offs and dropped tools that didn't earn their costYou'd rather ship a check than write a document, and you use AI tools heavily without trusting them blindly

Bonus Attributes

Fintech, payments, or card issuing background (PCI DSS a plus)Pentest, bug bounty, or red team experienceExperience building security scanners, static analysis rules, or LLM-based review toolsIf you have the background: AI security for our agents and agentic payments, or corporate security alongside IT

Things that enable a fulfilling, healthy and happy experience at Rain:

• Unlimited time off
• Unlimited vacation can be daunting, so we require Rainmakers to take 10 days minimum for themselves.
• Flexible working
  We support a flexible workplace – work from home, come into an office, or both. We want everyone to work in an environment where they're their most confident and productive selves. New Rainmakers receive a stipend to set up a comfortable home workspace.
• Easy to access benefits
  For US Rainmakers, we cover 95% of your health, dental, and vision plan costs and 90% for your dependents, plus a 100% company-subsidized life insurance plan.
• Retirement goals
  Plan for the future with confidence. We offer a 401(k) with a 4% company match.
• Equity plan
  Every Rainmaker gets an equity option plan so we all benefit from our success.
• Health and Wellness
  High performance begins from within. Rainmakers receive a monthly stipend to be used for eligible health and wellness spending like gym memberships/fitness classes, massages, acupuncture - whatever recharges you!
• In-office meals
  Rainmakers working from the office enjoy lunch and dinner on us, covered with a DoorDash credit.
• Team summits
  Summits play an important role at Rain. Time together helps us build relationships and a common destiny. Expect team and company offsites, both domestic and international.