Senior Backend Software Engineer

Koyfin is a rapidly growing, VC-backed fintech startup looking for a Senior Backend Software Engineer to join a small team of very talented engineers to help scale our product to millions of users.We believe every investor deserves powerful, intuitive tools to analyze markets and portfolios—without the steep learning curve or sky-high costs of traditional platforms.That’s why we built Koyfin: a modern, accessible analytics platform that combines sleek visualizations, comprehensive data, and customizable tools to empower smarter investment decisions.

Our users love what we’ve created so far:

🥇 Fastest growing research platform for financial advisors using product-led growth (register for free)

🚀 Recognized by G2 as a top-rated analytics platform(link)

📈 Rapid growth with new records in usage and revenue every quarter

💰 We’re cash flow positive -and proud of itJoin our mission to transform the way financial data is accessed and used!

What you’ll be doing?You will join the

Application team and help deliver a comprehensive investment experience to our customers. Our tech stack includes TypeScript, Node.js, NestJS, React, RxJS, AWS, Kubernetes, MongoDB, and PostgreSQL. 

More specifically, you will:

• Be responsible for the end-to-end development and implementation of features
• Take ownership of features, from gathering requirements to realization, maintenance, and continuous improvement
• Design and implement scalable web services, applications, and APIs
• Work on transforming large and complex datasets into beautiful visualizations
• Identify bottlenecks and improve software efficiency
• Collaborate closely with product management and design teams to define feature requirements and deliver impactful products that enhance the customer experience

Who we’re looking for?

• 5+ years of experience in software engineering
• Strong experience with back-end technologies: Node.js, NestJS (or any other framework), SQL, and NoSQL databases
• Professional experience with ReactJS or another modern JavaScript web framework (Vue, Angular, Ember, etc.)
• A solid understanding of semantic HTML, CSS, and core JavaScript concepts
• Experience with infrastructure: Cloud computing (AWS), CI/CD, Kubernetes
• Understanding of design patterns, algorithms, and system design
• Great communication skills; curious, collaborative, humble, and an excellent problem solver
• Upper-Intermediate level of English

Will be a plus:

• Previous experience in a FinTech startup
• Experience with one or more JavaScript visualization packages such as D3, ReactViz, Victory, or similar

What we offer

• An open environment where problems are solved by honest and rigorous discussion
• Fast-growing fintech startup where each person has a big impact and receives feedback directly from users
• Flexible work schedule
• Fully remote work or access to a modern coworking space in the center of Kyiv
• Generous salary and bonus potential
• Health Insurance/Well-being payment
• Extra vacation days