
Senior Agentic Software Engineer | Poolday
A-Players · London, United Kingdom · Remote
- Professional Services
- 11–50 employees
- New York, New York
All reasons
- Open 293 days
In its favour
- Still listed on the employer's own board
**Europe based candidates | Remote**
A-Players is helping **Poolday** hire a **Senior Agentic Software Engineer** to build the core agent systems behind a next-generation AI-powered video editor. Poolday is creating a new category of creative tooling that combines a traditional timeline-based editor with autonomous AI agents that can understand intent, generate visuals, and manipulate projects end-to-end.
This role will work closely with the founders and early engineering team to design and implement the agentic architecture that powers the product. This is a high-ownership position with significant influence over system design, product direction, and engineering culture.
**About Poolday**
Poolday is building a modern video editor where users describe what they want, and intelligent agents assemble compositions, generate pixels, and perform edits autonomously. The product blends familiar creative workflows with cutting-edge agentic AI systems.
The founding team consists of experienced operators and builders with a strong track record of shipping complex products. Poolday is early-stage, product-driven, and focused on building category-defining creative tools.
**What You’ll Be Doing**
- Designing and building **multi-agent systems in TypeScript** , including a primary orchestration agent and specialized sub-agents
- Architecting agent workflows that interpret user intent, plan multi-step edits, and execute them across a video timeline
- Building the **interface layer between agents and the video editor** , enabling agents to read project state, issue commands, and observe results in real time
- Developing agent capabilities for scene composition, visual generation, timing adjustments, effects, and compositing
- Implementing **plan-and-execute loops** , recovery strategies, and feedback mechanisms for reliable autonomous editing
- Creating memory and context systems that allow agents to reason about project state, user preferences, and editing history
- Working closely with founders to shape both the product vision and the technical foundations of the platform
##### **What Poolday Is Looking For**
- **_Must-Have_**
- 5+ years of professional software engineering experience with strong system design skills
- Deep expertise in **TypeScript** , including building large, maintainable codebases
- Experience building complex front-end or editor-like applications using **React**
- Hands-on experience with **agentic systems** (e.g. LangChain.js, LangGraph.js, Vercel AI SDK, or custom agent frameworks)
- Strong understanding of agent orchestration patterns such as hierarchical delegation, multi-agent collaboration, and plan-and-execute loops
- Experience designing APIs or command layers to programmatically control complex applications
- Strong prompt engineering skills, including function calling and structured outputs
- Ability to work independently in ambiguous, fast-moving environments
**_Nice to Have_**
- Experience with video editing software, motion graphics, or creative tooling
- Familiarity with generative Al for images or video
- Experience building plugin systems or extensible application architectures
##### **Why Join Poolday**
This is a chance to help define how AI agents will power creative tools. You’ll work on a product where users describe an idea and watch agents build it - composing scenes, generating visuals, and assembling edits autonomously.
Poolday offers real ownership, deep technical challenges, and the opportunity to shape a product from early traction to scale.
Skills
- TypeScript
- React
- LangChain
- LangGraph
- Vercel
- Prompt Engineering
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