Senior Frontend Engineer
Block Labs • Portugal
Posted: April 30, 2026
Job Description
About Block Labs
Block Labs is a premier technology studio operating at the bleeding edge of Web3, Artificial Intelligence, and iGaming. We don't just ship features; we engineer high-scale, production-grade platforms that power the next generation of digital products.
We are a collective of senior engineers, product strategists, and builders who refuse to compromise on architecture. Whether we are designing autonomous multi-agent AI systems, building decentralized financial infrastructure, or architecting high-frequency iGaming platforms, our standard is excellence.
We move fast, but we build for the long term. If you are looking to work alongside a team that values deep technical expertise, thoughtful system design, and product ownership, Block Labs is where you belong.
About The Role
As a Senior Frontend Engineer, you will help build and ship high-performance, modular and visually distinct interfaces across our multi-tenant platforms. You will work within cross- functional teams of engineers, product managers and designers, owning the frontend layer that powers multiple white-labeled experiences for partner brands. This is a hands-on role with significant influence over our templating strategy, micro frontend architecture, performance budgets and frontend tooling. You will move quickly, leveraging modern AI-assisted development workflows to ship production-quality code at a pace that matches our delivery ambitions.
Key Responsibilities:
Rebuild an existing customer-facing product UI and launch a new branded experience for an incoming partner, both running on shared multi-tenant foundations
Design and own the templating and theming system that lets us spin up differentiated UIs per tenant without duplicating codebases
Architect and maintain micro frontend boundaries across our platforms so teams can ship independently while keeping shared user journeys consistent
Hit and defend strict Core Web Vitals targets (LCP, INP, CLS), enforcing performance budgets and shipping measurable optimisations
Build, maintain and refactor modular Next.js and React interfaces with reusability and tenant configurability as first-class concerns
Use AI coding tools (Cursor, Claude Code or equivalent) as a core part of your daily workflow to accelerate scaffolding, refactoring, test generation and overall shipping velocity
Collaborate with product and backend engineers to define API contracts, feature behaviour and tenant-specific configuration
Advocate for clean, testable and maintainable code through peer reviews, documentation and a strong shared design system
About You:
You have 5+ years of frontend engineering experience building production-grade, consumer-facing web applications
Deep expertise in React and modern TypeScript, with strong opinions on rendering strategies (SSR, SSG, ISR, React Server Components) and when to apply each
Experience with Next.js is a plus
Hands-on experience designing or maintaining multi-tenant frontends, including theming, templating, white-labeling or partner-configurable UI
Solid track record working with micro frontend architectures (module federation, monorepos, independent deployables) and a clear understanding of the trade-offs
Demonstrable experience hitting tight Core Web Vitals targets in real production environments: profiling LCP, optimising critical rendering paths, image and font strategies, code splitting, edge caching and server components
Fluency with AI-assisted development tools (Cursor, Claude Code, Copilot) and a clear point of view on how to use them to ship faster without compromising quality
Comfortable with modern build tools (Bun, Vite, Webpack, Turbopack) and testing frameworks (Playwright, Cypress, Vitest)
Working knowledge of DevOps practices and containerisation in cloud environments
Strong command of both verbal and written English
Background in fintech, DeFi, real-time gaming and entertainment platforms or other high-traffic consumer products is a strong plus
What kind of culture can I expect?
Mature, mission-driven, and low-ego. We value clarity over noise, outcomes over theatrics, and pace without chaos. If you’re one of the smartest minds in your craft and want to build with other experts, you’ll feel at home here.
Additional Content
About Block Labs
Block Labs is a premier technology studio operating at the bleeding edge of Web3, Artificial Intelligence, and iGaming. We don't just ship features; we engineer high-scale, production-grade platforms that power the next generation of digital products.
We are a collective of senior engineers, product strategists, and builders who refuse to compromise on architecture. Whether we are designing autonomous multi-agent AI systems, building decentralized financial infrastructure, or architecting high-frequency iGaming platforms, our standard is excellence.
We move fast, but we build for the long term. If you are looking to work alongside a team that values deep technical expertise, thoughtful system design, and product ownership, Block Labs is where you belong.
About The Role
As a Senior Frontend Engineer, you will help build and ship high-performance, modular and visually distinct interfaces across our multi-tenant platforms. You will work within cross- functional teams of engineers, product managers and designers, owning the frontend layer that powers multiple white-labeled experiences for partner brands. This is a hands-on role with significant influence over our templating strategy, micro frontend architecture, performance budgets and frontend tooling. You will move quickly, leveraging modern AI-assisted development workflows to ship production-quality code at a pace that matches our delivery ambitions.
Key Responsibilities:
Rebuild an existing customer-facing product UI and launch a new branded experience for an incoming partner, both running on shared multi-tenant foundations
Design and own the templating and theming system that lets us spin up differentiated UIs per tenant without duplicating codebases
Architect and maintain micro frontend boundaries across our platforms so teams can ship independently while keeping shared user journeys consistent
Hit and defend strict Core Web Vitals targets (LCP, INP, CLS), enforcing performance budgets and shipping measurable optimisations
Build, maintain and refactor modular Next.js and React interfaces with reusability and tenant configurability as first-class concerns
Use AI coding tools (Cursor, Claude Code or equivalent) as a core part of your daily workflow to accelerate scaffolding, refactoring, test generation and overall shipping velocity
Collaborate with product and backend engineers to define API contracts, feature behaviour and tenant-specific configuration
Advocate for clean, testable and maintainable code through peer reviews, documentation and a strong shared design system
About You:
You have 5+ years of frontend engineering experience building production-grade, consumer-facing web applications
Deep expertise in React and modern TypeScript, with strong opinions on rendering strategies (SSR, SSG, ISR, React Server Components) and when to apply each
Experience with Next.js is a plus
Hands-on experience designing or maintaining multi-tenant frontends, including theming, templating, white-labeling or partner-configurable UI
Solid track record working with micro frontend architectures (module federation, monorepos, independent deployables) and a clear understanding of the trade-offs
Demonstrable experience hitting tight Core Web Vitals targets in real production environments: profiling LCP, optimising critical rendering paths, image and font strategies, code splitting, edge caching and server components
Fluency with AI-assisted development tools (Cursor, Claude Code, Copilot) and a clear point of view on how to use them to ship faster without compromising quality
Comfortable with modern build tools (Bun, Vite, Webpack, Turbopack) and testing frameworks (Playwright, Cypress, Vitest)
Working knowledge of DevOps practices and containerisation in cloud environments
Strong command of both verbal and written English
Background in fintech, DeFi, real-time gaming and entertainment platforms or other high-traffic consumer products is a strong plus
What kind of culture can I expect?
Mature, mission-driven, and low-ego. We value clarity over noise, outcomes over theatrics, and pace without chaos. If you’re one of the smartest minds in your craft and want to build with other experts, you’ll feel at home here.