Software Engineer, AI Developer Platform

Mirage is an AI video company focused on making creation dramatically easier. Our team tackles some of the hardest creative and technical challenges in generative media. We get to rethink how people collaborate with AI that can actually do creative work with them—defining entirely new interaction paradigms for AI-native video tools. We make that possible by building multimodal agents that turn creative direction into edits, rendering engines that composite multiple layers of video and graphics, and generative video models trained from the ground up that create new media when needed. All of this comes together in Captions, our creative workspace for generating, editing, and designing video. The technology behind Captions is now available more broadly: Tesseract gives any AI agent native video-editing capabilities, while developers can integrate our models into their own products through APIs. Explore our work Captions https://apps.apple.com/us/app/captions-ai-edits-your-video/id1541407007 — Our flagship creative workspace Tesseract https://x.com/trymirage/status/2102429594804429138 — Our professional video engine for AI agents Research https://mirage.app/research?utm_source=chatgpt.com — The foundation models we build in-house Updates https://x.com/trymirage — The latest from Mirage TechCrunch https://techcrunch.com/2026/03/24/mirage-raises-75m-to-continue-building-models-for-its-ai-video-editing-app-captions/, Forbes https://www.forbes.com/companies/captions/?list=ai50, Fast Company https://www.fastcompany.com/91270234/video-most-innovative-companies-fast-company-2025-youtube-roku-tubi-vimeo-captions-descript-cour-procreate-synthesia-beeble — Press Our Investors We’re very fortunate to have some the best investors and entrepreneurs backing us, including Index Ventures, Kleiner Perkins, Sequoia Capital, Andreessen Horowitz, General Catalyst, Uncommon Projects, Kevin Systrom, Mike Krieger, Lenny Rachitsky, Antoine Martin, Julie Zhuo, Ben Rubin, Jaren Glover, SVAngel, 20VC, Ludlow Ventures, Chapter One, and more. Please note that most of our roles will require you to be in-person at our NYC HQ (located in Union Square) 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 - Dinner stipend every night if you're working late and want a bite! - Grubhub subscription - Health & Wellness Perks - Multiple team offsites per year with team events every month - Generous PTO policy Captions provides equal employment opportunities to all employees and applicants for employment and prohibits discrimination and harassment of any type without regard to race, color, religion, age, sex, national origin, disability status, genetics, protected veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by federal, state or local laws. Please note benefits apply to full time employees only.