About the role

Software Engineer building real-time anti-abuse and detection systems for Resend’s developer email platform. Designing enforcement, ML classifiers, and safeguards against spam, phishing, and account takeover.

Responsibilities

Build and run the real-time enforcement layer within a millisecond latency budget
Design signal-to-decision-to-action pipelines across sending, receiving, and account activity
Build detection rules and policies and make them safe to change
Detect and contain account takeover and leaked API keys without locking out legitimate owners
Close the feedback loop by measuring detection precision and retiring rules that harm good senders
Automate investigations, appeals, and bulk actions
Build and evaluate ML classifiers for spam and phishing and validate precision before enforcement
Implement safeguards and ensure actions are traceable through logs, metrics, and audit trails
Shape technical decisions and take projects from discovery through production
Collaborate closely with developers using Resend's email platform

5+ years of software engineering experience
Fluent in written and spoken English
Deep experience with Node.js, TypeScript, React, Hono, and Next.js
Go experience or willingness to learn Go for latency-sensitive services
Infrastructure and reliability skills with AWS, CDK, and Datadog
Experience with APIs, event-driven architectures, queues, and stateful services
Ability to design systems that fail safe and treat false positives as bugs
Strong observability skills involving metrics, logs, tracing, and error handling
Ability to take ownership across the stack, from frontend surfaces to databases and queues
Proven database experience with Postgres and Redis
Trust and safety, fraud, or security experience is an exceptional-fit qualification
Experience building real-time enforcement such as rate limiting or rules engines using policy languages like CEL is an exceptional-fit qualification
Production experience shipping ML or LLM-based detection and measuring precision and recall is an exceptional-fit qualification
Knowledge of email systems including SPF, DKIM, DMARC, bounces, complaints, and phishing campaigns is an exceptional-fit qualification
Knowledge of Postgres and Redis performance tuning is an exceptional-fit qualification

Fully remote work
Travel for team offsites, conferences, meetups, and more
Room to shape technical decisions and take projects from discovery through production
Work remotely with teammates around the world
Close collaboration with the developers who use what you build
Thoughtful feedback, shared learning, and care for each other
High bar for product quality, reliability, and software usability