Nelo

fintech

SeniorSecurityEngineer

Mexico City, Mexico; New York City, New York, United States FULL TIME
Market Sentiment
HIGH DEMAND

Neural analysis suggests this role is
optimal for Senior candidates.

The Brief

“Senior Security Engineer at Nelo. Skills: Application security, Cloud infrastructure security, Security program development. Build secure-by-default systems. Design security guardrails”

What You'll Achieve.

Increase buying power of consumers; Balance risk against velocity; Turn one-off issues into systemic improvements; Automate evidence collection

Industry & Context.

fintech

What They're Looking For.

Must Have

Engineering background with substantial time spent on security in production environments, hands-on experience with cloud security fundamentals, ideally on AWS, Comfortable building and modifying infrastructure with Terraform or equivalent IaC tooling, You ship code and own outcomes, not just recommendations signals, You have taken a company through SOC 2, ISO 27001, or a comparable certification, You have personally run a bug bounty program or managed external pentests, Depth in AWS security primitives such as GuardDuty, CloudTrail, IAM, VPC, KMS, and security groups, You use Claude Code or other agentic coding tools as part of your daily workflow

Nice to Have

built security programs at a startup before, write code and ship infrastructure yourself, deep AWS instincts, taken a company through SOC 2 or a comparable certification, comfortable with AI tools as part of your daily workflow, can hold a security position and still ship product on time

What You'll Do.

Build secure-by-default systems

Design security guardrails

Implement security guardrails

Improve secrets management

Improve endpoint management

Improve access controls

Harden AWS infrastructure

Increase security observability

Treat security as engineering problem

Write code for controls

Write configs for controls

Write tooling for controls

Replace manual reviews with automation

Make secure path default

Run external security programs

Own penetration tests

Own bug bounty program

Partner with engineers on fixes

Turn issues into improvements

Take Nelo through SOC 2

Build automated evidence collection

Raise bar across engineering

Set standard through implementations

How You'll Work.

Team & Collaboration

Partner with engineers on fixes; Work directly with CTO; Work with CEO; Work with engineering leadership

Full Job Description

SECURITY ENGINEER ABOUT NELO Nelo is a leading consumer fintech and e-commerce platform in Mexico, with >$500MM in annualized GMV and >$75MM in annualized revenue. Our mission is to increase the buying power of consumers in Latin America, and we are doing so by building a modern alternative to credit cards. Nelo has raised over $40M of venture capital from investors including Homebrew, Two Sigma Ventures and Susa Ventures. Nelo has additionally raised a $100M asset credit facility from Victory Park Capital. Our lean team includes experienced leaders from top technology companies including Uber, Amazon, Rappi, and DiDi. We pride ourselves on our velocity, intellectual rigor, and efficiency. Nelo has offices in Mexico City and New York City. ABOUT THE ROLE Security has been part of how Nelo builds software from day one. As we scale, we are creating a dedicated Security Engineer role with broad ownership across application security, cloud infrastructure, and internal controls. This is a hands-on role for someone who wants to define the security function rather than inherit it. You will decide where to invest, implement controls yourself, and balance risk against velocity in a fast-moving lending business. You will work directly with the CTO, the CEO, and engineering leadership. This role is in-person at our Mexico City office in Condesa. WHAT YOU'LL DO Build secure-by-default systems - Design and implement security guardrails across cloud infrastructure and developer workflows - Improve IAM, secrets management, endpoint management, and access controls across production systems - Harden AWS infrastructure using Terraform and policy-as-code - Increase observability for security-relevant events and anomalies Treat security as an engineering problem - Write code, configs, and tooling to enforce controls - Replace manual reviews with automation wherever it makes sense - Make the secure path the default path for engineers Run external security programs - Own penetration test

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