Lead Software Engineer, Frontend Platform Team - Sievo Oy - Helsinki, Finland

As the Lead Software Engineer for our Frontend Platform team, your mission is to build a production-ready frontend ecosystem engineered from the ground up for autonomous and AI-assisted software development. This is a greenfield role where you will scale our early-stage architecture into a robust production environment and establish our core design system from scratch. Instead of building a traditional developer platform solely for human engineers, you will design a highly deterministic repository structure, runtime abstractions, and strict architectural guardrails. Your primary goal is to ensure that AI agents have the high-fidelity context, type safety, and safety nets they need to safely ship high-performance UI features for our 5+ product engineering teams. You will head our Frontend Center of Excellence, redefining what it means to build software when AI is the primary author. What you’ll do Lead the Center of Excellence: guide both the frontend community and the wider engineering org as we shift to AI-native software development. You'll set the standards that make this feel natural: prompt engineering practices, clear repository boundaries, and automated code mods that keep quality high as development accelerates. Harden the Autonomous Platform Foundation: Take our early-stage frontend architecture to production, establishing a highly performant monorepo structure, efficient local development setups, and automated CI/CD pipelines optimized for rapid development loops. Co-create the Design System: Partner directly with Product Design to launch a token-driven, highly composable component library from scratch, establishing automated design-to-code synchronization and deterministic component behaviors that make UI assembly foolproof for AI agents. Enable Product Team Autonomy: Design a self-service platform infrastructure, including instant preview environments, and isolated local development workspaces, that allows feature teams to independently test and deploy their workloads end-to-end. Engineer the LLM Context Layer: Design and maintain the repository's semantic context layer, including structured markdown rules, machine-readable architectural manifests, and tight end-to-end TypeScript types, ensuring AI coding tools possess perfect context of system boundaries. What we're looking for Engineering Leadership: You know how to bring people along, not just set direction. You're comfortable influencing without authority and building trust across product, design, and engineering teams. Scaling Frontend Platforms: Proven track record of scaling a shared frontend platform across multiple distributed engineering teams. You understand the full lifecycle of platform ownership, including managing shared package dependencies, controlling bundle-size bloat, handling zero-downtime framework upgrades, and measuring developer friction to clear delivery bottlenecks. Decentralized Platform Philosophy: A clear architectural preference for building self-service, decoupled developer tools (such as isolated preview environments and custom CLIs) that eliminate centralized engineering bottlenecks. Component-Driven API Design: Deep experience engineering reusable UI primitives with strict separation of concerns (such as headless UI or design-token-driven architectures), utilizing explicit, typed contracts rather than fragile, highly mutable component configurations. Modern Tooling Fluency: Deep technical expertise in TypeScript and contemporary frontend web architectures (e.g. Vite, Turborepo, Nx, and package-manager workspaces) with a strong focus on maximizing local development speed.