Mid Backend Developer Jobs in Duarte, CA (NOW HIRING)

Location: Santa Ana, California - on-site
Employment type: Full-time
Salary:  $120,000 - $155,000

Created.ai is an AI-powered creative platform combining text, image and video generation into production tools for commercial creative work. The platform is operated by eJam, a multi-brand consumer products and technology company.

We are expanding our engineering team with two appointments covering our AI platform infrastructure and our product engineering surface. Both roles carry substantial technical ownership and report directly into engineering leadership.

This position is AI-native by design. Our engineers work with agentic coding tools as a primary part of their daily workflow, which allows a small team to operate at a scope that would conventionally require a much larger one. We are looking for engineers whose judgement, architectural thinking and review discipline scale that leverage rather than being replaced by it.

We are seeking a Mid-Level Engineer to build and ship features across the created.ai product experience - from the browser client through our NestJS API to the Python AI services that power generation, and back out to how results are presented in the interface.

You will work within an established architecture rather than defining it. A staff engineer sets the platform patterns and a senior engineer reviews your design decisions; your job is to take a well-specified problem, build it properly across the stack, and ship it to production. Over time we expect you to take on progressively larger and less-specified pieces of work.

This suits an engineer with two to four years of production experience who is stronger than their years suggest, wants to work on generative creative tooling, and would rather ship user-facing product than maintain someone else's backlog.

• Build and ship end-to-end product features across the request path, working from specifications you help refine
• Implement asynchronous user experiences - progress states, partial failures and recovery paths - using the patterns our platform already establishes
• Consume and extend typed API contracts between the web client, NestJS services and Python AI services
• Build interface components that are consistent with our existing design and component system
• Write and maintain automated tests for the code you ship, at unit and integration level
• Take part in code review, both giving and receiving it, and act on the feedback
• Work with product colleagues to turn creative-tooling ideas into shippable scope

Requirements

• Two to four years of professional software engineering experience shipping to production
• Strong React and TypeScript - you have built and maintained real components in a real codebase, and you understand the type system rather than fighting it
• Comfortable in a modern React toolchain (Next.js, Vite or comparable)
• Working knowledge of a Node.js backend framework and a relational database - you can add an endpoint, write a query and reason about the data model
• Experience with asynchronous UI: loading and error states, polling or streaming, and what to show a user when something takes thirty seconds or fails halfway
• Automated testing as a normal part of your work, in any mainstream framework
• Fluency with agentic coding tools (Claude Code, Codex, Cursor or comparable) - specifically, the judgement to review generated code critically rather than shipping it unread, and the honesty to say when you do not understand what it produced
• Able to read code confidently in a language you do not primarily write in

None of the following are required. Tell us if you have any of them.

• Mantine or another component library at production scale
• TanStack Query or comparable client-state tooling
• NestJS specifically
• SSE or WebSockets, including reconnection and partial-failure handling
• Playwright or another end-to-end testing framework
• File upload handling, or image and video asset pipelines
• Any Python at all - enough to read a FastAPI service and make a small change is genuinely useful here
• Canvas, timeline or media-editor work: Pixi, Fabric, Remotion, WebGL or comparable
• Exposure to MCP, tool calling or agent-driven interfaces

How you will grow here

You will be the most junior engineer on a small, senior team, which is the fastest way to get better and also occasionally uncomfortable. You will get substantive code review from people with more experience than you, direct exposure to architectural decisions before they are made, and a defined path toward owning full vertical slices of the product. We will tell you plainly where you stand and what would move you to the next level.

Benefits

• Health, Dental, Vision
• 401k Plan
• PTO Plan
• 14 observed local holidays
• Stock options
• Amazing, pet-friendly office environment
• Equipment budget and learning allowance
• Real technical ownership within a small engineering team, and visible impact on a commercially active AI product with real users and real scale constraints
• Direct involvement in product decisions - the team is small enough that there is nowhere to hide, in both directions