Senior Fullstack Engineer (React)

Gain is the Private Markets Super App, a connected global platform transforming how leading investors, advisors, and corporates source, evaluate, and execute deals. By combining investment-grade intelligence, AI-powered workflows, and proprietary data in one unified platform, Gain enables top deal teams to move faster, reduce risk, and build conviction with confidence.

Gain is trusted across more than $1 trillion of private capital, used by 100% of MBB and Big Four firms, and by 80% of the world’s top 20 M&A advisory houses.

Recognized for fast innovation and impact, Gain has been named both US and EU Data Provider of the Year by PE Wire, awarded Global Financial Market Review’s Best Use of AI in Finance, and ranked in Sifted’s Top 100 Fastest-Growing Companies, the Forbes 1000, and the Deloitte Technology Fast 50. Gain operates globally with offices in New York, London, Amsterdam, Frankfurt, Warsaw, and Bangalore.

As a frontend-focused Fullstack Engineer, you spend most of your time building features and maintaining our React/TypeScript codebase, and you're comfortable working across the stack into our Go backend when a feature calls for it. You balance high-quality craftsmanship with pragmatic delivery, and collaborate closely with Product, Design, and other engineers to drive architectural improvements and raise engineering standards through mentorship, code reviews, and technical leadership. You think beyond the code, connecting your work to business impact and strategically planning for the platform's future.

Our Engineering team is based in Amsterdam, where most of us typically work 2 days a week onsite. We are a team of engineers (Backend, Frontend, Data, DevOps and ML) and a handful of colleagues in Product and Design. Together, we operate in an efficient and pragmatic way, where everyone’s voice is heard. Apart from a short daily stand-up, we aim to keep meetings to a minimum. Team events are held on a monthly basis to foster collaboration, enhance communication, and boost morale.

• 10+ years of software development

• 5+ years of recent React/TypeScript experience

• Deep knowledge of React architecture, state management patterns, and modern best practices

• Experience with TypeScript in large-scale codebases

• Understanding of semantic HTML and responsive CSS

• Experience optimizing front-end performance and build pipelines

• 3+ years of backend development experience

• Working knowledge of SQL and relational database design

• Understanding of front-end/back-end boundaries and API contracts

• Experience mentoring engineers and driving engineering quality standards

• Experience with MUI

• Experience with Go and PostgreSQL

• Experience with Google Cloud architecture / infrastructure

• Experience in FinTech, economics, or private equity