Founding Engineer
Location: Remote (EU) / Hybrid (Cracow)
Tech Stack: React, Node.js, TypeScript, PostgreSQL, AWS, Docker
TLDR
We are building the operating system for the world's storytellers. We reject "good enough" in favor of radical simplicity and deep craftsmanship.
The Work: We build the industry standard, not just tickets. We obsess over details and prioritize impact over busywork.
The Culture: Context over control. We trust you to make decisions. No micromanagement, just clear expectations and support.
The Goal: To bring the magic back to software. We are a team of relentless optimists building tools that feel inevitable.
If you care about quality and want to do the best work of your life, you belong here.
We are building the missing financial layer of the modern project management stack. Built for Humans, AI, and whatever comes next.
We’re assembling a top-tier founding team and we’re looking for the brightest engineers with startup experience and a founder mindset.
If you’re looking for a comfortable job with well-defined tasks, this isn’t it. If you want to build and ship at breakneck speed, own massive impact, and shape a world-class product from day one, let’s talk.
About Splinde
We are engineering the next generation of financial modeling, built for humans and ready for agents. Forget standard CRUD, we are building a high-performance visual runtime that renders complex financial graphs in the browser. You will architect a reactive, node-based system that challenges the limits of modern web performance. We are looking for a leader who craves deep complexity, rapid deployment cycles, and the autonomy to define the stack that powers the next generation of project finance.
Back in 2020, our founder Joshua was deep in the trenches as a Commercial Film Producer in Germany. He built an Excel sheet to handle international budgets, and guess what? It became the industry standard! Over 300 companies rely on it today. As a producer, developer, and the industry's "Excel-guy", Joshua saw the gap. The industry needed a tool that could actually handle the complexity and speed of modern production. That’s how the vision started. Now, we're building the future of budget management: for humans and AI!
The Opportunity
As the Lead Developer, you won't just be writing code; you will be architecting a high-performance visual engine capable of rendering thousands of nodes in the browser while maintaining real-time data integrity across a complex distributed system. You will oversee our infrastructure from Docker environments to production AWS deployments.
Key Challenges & Responsibilities
1. High-Performance Frontend Architecture You will own the performance of our React SPA, specifically regarding large-scale data presentation.
Tree Virtualization: Architect algorithms to flatten deeply nested data into performant, virtualized list views (DOM-based).
Performance: Ensure 60fps scrolling for thousands of items using memoization & virtualization.
State Management: Architect granular Valtio state solutions to prevent expensive re-renders across the tree.
2. Scalable Backend & Real-Time Collaboration
You will maintain and evolve a Node.js backend designed for complexity and speed.
Data Modeling: Manage complex budget structures and migrations in PostgreSQL using Prisma and raw SQL.
Real-Time Systems: Architect and maintain WebSocket and Redis implementations to enable live, multi-user collaboration on budget flows.
3. Infrastructure Stability & Maintenance You will maintain our existing stack, ensuring smooth delivery from Local to Production without rebuilding operations.
Cloud Health: Oversee the health of our current AWS infrastructure (CDK) and RDS databases.
Pipeline Stewardship: Keep GitLab CI/CD pipelines green and efficient, troubleshooting occasional build issues.
Containerization: Maintain Docker setups to keep environments running smoothly.
Requirements
Must-Have
Startup experience and founder mindset – You’ve built things from scratch, owned projects end-to-end, and think like an entrepreneur. You’re not just here to build a product; you’re here to help build the company. We don’t work in silos — it’s crucial to understand our domain, our customers’ problems, and how we solve them. You think beyond code and care about the bigger picture.
Speed – You turn ideas into shipped features in days, not weeks, and thrive in a fast-moving environment. We are not waiting for the next weekly, we jump on a huddle and ship.
Curiosity and continuous learning – You have a deep curiosity about how things work and how they could work better. You’re not just focused on technology but also on business, customers, and what makes startups succeed. You see every challenge as an opportunity to learn, grow, and push beyond what you already know.
Boldness to step outside your comfort zone – You take on challenges that stretch your abilities, experiment without hesitation, and embrace the unknown.
Full-stack mastery with modern TypeScript stack – You can own entire features from backend to frontend.
Track record of maintaining large codebases with growing teams – You write scalable, maintainable code and have experience with long-term tech decisions.
Experience with React and Node.js – You can build and ship high-quality web applications.
Excellent taste in product and UI design – You have a strong sense of what makes a great user experience and care about the details.
Comfortable talking to customers – You’re not afraid to jump on a call, understand their needs, and get direct feedback.
Genuine passion for AI tools of the future – You’ve likely built something with LLMs just for fun or to solve a real problem.
React Proficiency: Proven experience with complex React applications, performance profiling, and optimization (memoization, virtualization).
Backend Experience: Experience with Node.js and relational databases (PostgreSQL).
DevOps Literacy: Comfortable with Docker, Docker Compose, and CI/CD configurations.
Nice-to-Have (The "Perfect Fit")
Background in building collaborative multi-user applications (with Yjs).
Experience with Valtio for proxy-based state management.
Experience with TanStack Query (React Query).
Experience with AWS CDK or CloudFormation.
Custom UI design systems/components
Realtime collaborative features using Websockets, tRPC, YJS etc.
Cultural Fit: The "Founder Mode" Mindset
Radical Ownership (The "Buck Stops Here"): You don't just pick up tickets; you own the outcome. You treat the codebase, the infrastructure, and the user experience as your own assets.
Strategic Urgency: We are a startup moving at high velocity. You possess an innate bias for action and understand that momentum is oxygen. You distinguish between "rushing" (reckless) and "speed" (efficient execution).
High-Stakes Reliability: You understand that while we move fast, financial integrity is non-negotiable. You have the maturity to balance feature delivery with architectural stability.