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Senior Frontend Engineer with 6+ years of experience building large-scale, production-grade web applications. I work primarily with React and Next.js, focusing on frontend systems that operate under real traffic and real business constraints. My experience includes performance-critical environments, experimentation-driven development, and highly observable production systems. I care about building frontends that are reliable, scalable, and easy to evolve over time. I treat performance as a product feature, not a post-launch optimization, and I value clear architecture, strong observability, and thoughtful technical trade-offs. I’ve worked closely with product, design, and backend teams in mature engineering organizations, contributing not just code, but technical judgment and ownership in live production environments.…Senior Frontend Engineer with 6+ years of experience building large-scale, production-grade web applications. I work primarily with React and Next.js, focusing on frontend systems that operate under real traffic and real business constraints. My experience includes performance-critical environments, experimentation-driven development, and highly observable production systems. I care about building frontends that are reliable, scalable, and easy to evolve over time. I treat performance as a product feature, not a post-launch optimization, and I value clear architecture, strong observability, and thoughtful technical trade-offs. I’ve worked closely with product, design, and backend teams in mature engineering organizations, contributing not just code, but technical judgment and ownership in live production environments.

Sergi Botargues

Front-End Developer, Full Stack Developer, Web Developer, +6

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Senior Frontend Engineer with 6+ years of experience building large-scale, production-grade web applications. I work primarily with React and Next.js, focusing on frontend systems that operate under real traffic and real business constraints. My experience includes performance-critical environments, experimentation-driven development, and highly observable production systems. I care about building frontends that are reliable, scalable, and easy to evolve over time. I treat performance as a product feature, not a post-launch optimization, and I value clear architecture, strong observability, and thoughtful technical trade-offs. I’ve worked closely with product, design, and backend teams in mature engineering organizations, contributing not just code, but technical judgment and ownership in live production environments.…Senior Frontend Engineer with 6+ years of experience building large-scale, production-grade web applications. I work primarily with React and Next.js, focusing on frontend systems that operate under real traffic and real business constraints. My experience includes performance-critical environments, experimentation-driven development, and highly observable production systems. I care about building frontends that are reliable, scalable, and easy to evolve over time. I treat performance as a product feature, not a post-launch optimization, and I value clear architecture, strong observability, and thoughtful technical trade-offs. I’ve worked closely with product, design, and backend teams in mature engineering organizations, contributing not just code, but technical judgment and ownership in live production environments.

Available to hire

Barcelona, Spain

Senior Frontend Engineer with 6+ years of experience building large-scale, production-grade web applications.

I work primarily with React and Next.js, focusing on frontend systems that operate under real traffic and real business constraints. My experience includes performance-critical environments, experimentation-driven development, and highly observable production systems.

I care about building frontends that are reliable, scalable, and easy to evolve over time. I treat performance as a product feature, not a post-launch optimization, and I value clear architecture, strong observability, and thoughtful technical trade-offs.

I’ve worked closely with product, design, and backend teams in mature engineering organizations, contributing not just code, but technical judgment and ownership in live production environments.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Language

Spanish; Castilian

Fluent

Catalan; Valencian

Fluent

English

Fluent

Work Experience

Frontend Developer at Mango

December 1, 2023 - Present

Work in a large-scale, high-traffic global e-commerce platform using Next.js in production environment. Contributing to performance-critical frontend systems, with a strong focus on reliability, scalability, and user experience. Implementing advanced caching and CDN strategies using Akamai to optimize global delivery. Designing and running A/B tests with Optimizely to support data-driven product decisions. Monitoring and debugging production issues using Dynatrace in a highly observable environment. Collaborating with product, UX, and backend teams in a mature frontend organization with strong engineering standards.

Software Developer at GoStudent

March 1, 2022 - December 1, 2023

Contributed to multiple projects with different architecture and technical constraints. Adapted quickly to diverse code bases and stacks, working across frontend and backend boundaries. Strengthened problem-solving skills by delivering features in fast-moving environments.

Software Developer at Niikiis

February 1, 2020 - April 1, 2021

Built internal HR tools for companies using React, Node.js, and AWS. Worked extensively with AWS services, including serverless architectures. Developed and maintained production features with a strong focus on reliability and maintainability. Core expertise: Production-first mindset; strong architectural judgment in evolving large frontend codebases without disrupting production. Performance treated as a production feature, not a post-launch optimization. Ability to balance experimentation speed with system stability in live environments. Comfortable operating under real traffic, partial failures, and imperfect constraints. Clear technical communication with product and design to align engineering and business goals.

Frontend Developer at Mango / GoStudent

December 1, 2023 - Present

Frontend development for a large-scale, high-traffic global e-commerce/education platform using Next.js in production. Contributing to performance-critical frontend systems with a strong focus on reliability, scalability, and user experience. Implemented advanced caching and CDN strategies (Akamai) to optimize global delivery. Designed and ran A/B experiments (Optimizely) to support data-driven product decisions. Monitored and debugged production issues (Dynatrace) in a highly observable environment. Collaborated with product, UX, and backend teams in a mature frontend organization with strong engineering standards.

Software Developer at Team No Box

March 1, 2021 - March 1, 2022

Contributed to multiple projects with different architectures and technical constraints. Adapted quickly to diverse code bases and stacks, working across frontend and backend boundaries. Strengthened problem-solving skills by delivering features in fast-moving environments.

Front-End Developer at Mango

December 1, 2023 - Present

Worked on a large-scale, high-traffic global e-commerce platform using Next.js in production. Contributed to performance-critical frontend systems with focus on reliability, scalability, and user experience. Implemented advanced caching and CDN strategies using Akamai to optimize global delivery. Designed and ran AB experiments with Optimizely to support data-driven product decisions. Monitored and debugged production issues using Dynatrace in a highly observable environment. Collaborated with product, UX, and backend teams in a mature frontend organization with strong engineering standards.

Software Developer at GoStudent

March 1, 2021 - March 1, 2022

Developed and maintained a large-scale virtual classroom platform used by thousands of students and teachers. Worked on real-time and interaction-heavy features such as video calls and collaborative whiteboards. Focused on frontend architecture, complex state management, and performance using React and TypeScript. Collaborated with cross-functional teams to deliver reliable, user-centered features in production.

Software Developer at NIIK IIS

February 1, 2020 - April 1, 2021