Software Engineer, AI Developer Platform

About the role

Mirage is hiring a backend engineer to rebuild how we ship software as AI agents dramatically increase the volume of code we produce. You’ll own the path from commit to production, ensuring our build, test, review, deployment, and security systems help engineers and their agents ship quickly and safely.

You’ll treat our development infrastructure like a product—working directly with engineers to understand friction, measure bottlenecks, and build tools they want to use. You’ll also ship features across our AI video products and developer platform, grounding those improvements in firsthand experience.

While we don’t use hierarchical titles or levels internally, we are currently hiring engineers who have operated at senior or staff+ scope.

Responsibilities

• Ship features alongside product engineers across our video creation software, video rendering engine, and developer platform, identifying where our development systems slow them down

• Turn those insights into tools, agents, and streamlined workflows that engineers choose because they’re the fastest way to ship

• Rebuild CI/CD to support 100x the change volume through fast incremental builds, test selection, automated flaky-test detection and quarantine, merge queues, and preview environments

• Make deployments safe by default through progressive rollouts, automated canary analysis, feature flags, and automatic rollback, catching bad changes within minutes before they affect users

• Own the environments coding agents work in, including sandboxes, ephemeral stacks, and the tooling agents need to build, test, and verify their own work

• Build an AI review pipeline with agent reviewers tuned to our codebase, risk-based routing that directs risky changes to humans, and automated policy checks that gate merges

• Run continuous, agent-driven penetration testing against our applications, APIs, and infrastructure, moving beyond point-in-time annual audits and turning findings into pull requests with proposed fixes

• Integrate security into the development pipeline through secrets, dependency, and supply-chain scanning, AI-assisted vulnerability triage, and automatically generated fix PRs

• Secure agents’ access to code, infrastructure, and data through least-privilege permissions, short-lived credentials, sandboxing, audit logs, and prompt-injection guardrails

• Measure and improve the development lifecycle, with early priorities including reducing PR-to-production time as weekly merged PRs grow 10x, replacing long-lived credentials in CI and agent environments, and driving flaky tests close to zero through automated detection, quarantine, and fix PRs

What Makes You a Great Fit

• 5+ years of professional experience building backend or full-stack software, with a track record of shipping high-impact products or systems end-to-end

• Strong product sense—you’ve shipped things users love and bring that same attention to engineers and agents as users of your systems

• Hands-on experience with CI/CD, cloud infrastructure, or security, and the drive to go deep; specialists and product engineers ready to specialize are both welcome

• Extensive use of coding agents in your current work, with informed opinions about where they break

• Strong security instincts, including thinking through how a system could be attacked while you’re building it

• A practical, measurement-driven approach—you measure before you fix and would rather ship an effective solution this week than wait a quarter for a perfect one

• Comfort owning build, deployment, review, and security together, working across layers and defining a roadmap where no playbook exists

• An interest in staying close to product, shipping to production every week, and using firsthand experience to guide infrastructure improvements

• A preference for making the right path easy to follow through useful tools and thoughtful defaults

Even better if...

• You’re a product engineer who keeps getting pulled into build, deployment, or security problems and wants to make that your focus

• You’ve built internal developer platforms or productivity tooling at a fast-growing startup

• You have offensive security experience, including penetration testing, red-teaming, bug bounties, or CTFs

• You’ve shipped LLM agents or evaluations that run in production

• You’ve worked with merge queues, monorepo tooling, or test-impact analysis

• You’ve been a startup founder or an early engineer at one

Benefits:

• Comprehensive medical, dental, and vision plans

• 401K with employer match

• Commuter Benefits

• Catered lunch multiple days per week

• Grubhub subscription

• Health & Wellness Perks

• Generous PTO policy