Sergio Collado Vázquez

CTO & Co-Founder

Synkross, Madrid and Luxembourg

Synkross is a custom software company based in Madrid and Luxembourg that builds, scales and rescues digital products for companies and startups, with a fully senior team and more than 20 products in production. As CTO and co-founder I lead the technical direction, architecture and software delivery, owning each product from requirements to production.

• Design the architecture and build the complete product, web, mobile app, backend, payments, integrations and infrastructure, from the first meeting to production.
• Lead the engineering team and define the standards for code, quality and delivery.
• Take AI to production, with language models integrated into real products.
• Run our own infrastructure, with Kubernetes, CI/CD, monitoring and backups, plus the maintenance of every product in production.
• Work directly with founders and business stakeholders to turn product requirements into technical decisions.
• Clients and products include Airplane Solutions, Sense Living, CSC Tech, Caytco, Kelimbo, Fliply, Stowly and Buddy Market, among others.

Technologies: TypeScript, Next.js, React Native, Node.js, PostgreSQL, Prisma, Stripe, Docker, Kubernetes and language models

Front End Tech Lead

Garaje de Ideas, Madrid

Garaje de Ideas is a digital product design and development consultancy based in Madrid that works for large brands. I was Front End Tech Lead for the new web platform and CMS of an international pharmaceutical company, with full internationalisation by country and language.

• Defined the frontend architecture, its integration with the CMS and the coding standards of the project.
• Designed the internationalisation by country and language, covering content, routes and components, so a single product could be deployed across several markets.

Technologies: React, Next.js, TypeScript, automated testing, Jira, Confluence and Notion

Freelance Full Stack Engineer

Freelance, Madrid

Alongside the positions of this period I built custom web and mobile applications for companies and startups that needed a complete product with a single technical owner, deployment and maintenance included. Synkross grew out of this work.

• Delivered products end to end, from technical design to production.
• Supported clients on product strategy and business decisions, not only on the technical side.

Technologies: JavaScript, TypeScript, React, Next.js, React Native, Node.js, PostgreSQL, Prisma, Storybook, Leaflet, WebSocket, Stripe, Docker, Kubernetes, Jest, Cypress, Google Optimize and Google Analytics

Software Engineer

IKEA, Madrid

IKEA is the largest furniture and home furnishing group in the world and, with more than 400 restaurants and around 700 million diners a year, also one of the largest food service chains on the planet. I worked as Software Engineer on the new international food platform, with e-commerce and landing pages for several markets, and was the team's technical reference for Next.js and design systems.

• Built features of the international food e-commerce platform and created and optimised landing pages for different countries.
• Rolled out the IKEA design system (Skapa) across all projects, extended it with custom components and documented the library in Storybook for Next.js.
• Trained the development team in Next.js and engineering best practices.
• Trained the design team to work with development on the design system and defined the workflow between design and development.

Technologies: Next.js, React, TypeScript and Storybook

Front End Engineer, Fotocasa

Adevinta Spain, Madrid

Adevinta Spain is the marketplace group behind Fotocasa, InfoJobs, Milanuncios, coches.net and habitaclia. Fotocasa is the leading real estate portal for buying and renting homes in Spain and Andorra. I was Front End Engineer on the team that built the new management panel for real estate agencies.

• Defined and built panel features end to end, maintaining and refactoring code with test coverage.
• Drove code and tooling improvements in a team with a strong review and feedback culture, alongside Miguel Ángel Durán (midudev).
• Took part in continuous integration and observability with Travis, Spinnaker, GitHub Actions and Datadog.

Technologies: React, SASS, MSW, Formik, Yup, Jest, Chai, Cypress, OpenSearch, Jira and Confluence

Front End Engineer

Fintonic, Madrid

Fintonic is one of the largest personal finance fintechs in Spain. Its app aggregates the user's accounts and offers tailored loans and insurance. As Front End Engineer I worked on the frontend of the loan assessment funnel.

• Built the loan application, assessment and offer flow on the web, with conversion, performance and measurement covered at every step.
• Connected the funnel to the backend assessment and offer services.

Technologies: Next.js, React, TypeScript, Storybook, Docker and Kubernetes

Front End Engineer

DataBeacon, Madrid

DataBeacon is a Madrid startup building AI-powered air traffic management software to prevent conflicts between flights. As Front End Engineer I built the air traffic control application from scratch together with the CTO.

• Built the real-time flight visualisation on a map, with Leaflet, tile layers and data received over WebSocket.
• Built the tools for controllers inside the application, such as distance measurement between aircraft and filters by flight level.
• Integrated the conflict prevention machine learning models into the interface.
• Created the application's own component library, with its design system documented in Storybook.
• Improved the office network infrastructure.

Technologies: React, TypeScript, Leaflet, WebSocket, Storybook and real-time data visualisation

CRO Developer, EDP Solar

EDP, Madrid

EDP Energía is the Spanish subsidiary of the EDP energy group. Its EDP Solar line sells photovoltaic self-consumption installations for homes and businesses. I was CRO Developer on the conversion optimisation team for the EDP Solar website, where users size their installation and request a quote.

• Built A/B tests on the solar calculator, which estimates the installation and budget from roof area and consumption, and on the quote request flow. The tests went beyond visuals and changed business logic, calculation rules and the offers shown to the customer.
• Built the variants of the contracting pages, modifying the original pages to improve conversion to quote.
• Measured every test in Google Optimize, analysed the results and shipped the winning variants to the live site.
• Built website customisations for campaigns and co-branded partnerships.

Technologies: JavaScript, HTML, CSS, Google Optimize and Google Analytics

Co-Founder & CEO

Cubik Systems, La Línea de la Concepción, Cádiz

Cubik Systems was an IT services company for businesses, individuals and the public sector in Andalusia, with a shop and repair workshop in La Línea de la Concepción. As co-founder and CEO I ran the business, the team and the relationship with clients and suppliers, and delivered the technical projects myself.

• Grew the company to serve businesses and public administrations across Andalusia from a single location.
• Built business software and custom websites for clients and public bodies.
• Designed and installed networks, servers, security and CCTV systems and POS systems.
• Assembled custom computers for office, home and gaming.

Founder & CEO

Nativa3D, La Línea de la Concepción, Cádiz

I founded and ran Nativa3D, a company designing, manufacturing and selling affordable, reliable 3D printers, with an online shop and wholesale distribution across Spain.

• Won first prize for best business project at Encuentro de Ideas del Estrecho 2015 (Zona Franca de Cádiz).
• Designed and manufactured our own range of 3D printers and brought it to market through the online shop.
• Turned the company into a national wholesaler of 3D printers, electronics, consumables and spare parts for shops and workshops across Spain.
• Opened an industrial maintenance line for 3D printers and water jet, laser and CNC cutting machines.