Software Engineer

Resend is growing fast, and there are now over 4 million developers using it. We’re building tools that make email better for developers. We care about dependable infrastructure, thoughtful design, and the experience of everyone building with our products.

In this role you'll build the anti-abuse systems that keep Resend open for good senders and closed to bad actors: real-time enforcement on every email, detection pipelines that scale with the platform, and automations that go from detection to action without waiting on a human.

This role is fully remote based in Americas or European timezones, with some expected travel for team offsites, conferences, meetups, and more.

Read more about how we work, how we hire, and what we value here.

In this role, you will…

• Build and run the real-time enforcement layer within a latency budget of milliseconds

• Design pipelines that move from signal to decision to action, across sending, receiving and account activity

• Build the detection rules and policies that decide when we act, and make them safe to change

• Detect and contain account takeover and leaked API keys: notice when a trusted account stops acting like itself, and stop the damage without locking out the real owner

• Close the feedback loop: every block and every reversal carries a reason, so we can measure each detection's precision and retire the ones that hurt good senders

• Automate manual work such as investigations, appeals and bulk actions, so the team keeps up as volume grows

• Build and evaluate ML classifiers for spam and phishing, and prove their precision before they enforce anything

• Implement safeguards and make every action traceable through logs, metrics and audit trails

• Ensure all enforcement actions are traceable with logs, metrics, and audit trails

You’ll be a great fit if you…

• Bring 5+ years of software engineering experience

• Are fluent in writing and speaking English

• Have deep experience with Node.js, TypeScript, React (Hono, Next.js)

• Write Go, or want to, for latency-sensitive services

• Have infrastructure and reliability skills (AWS, CDK, Datadog)