Senior Software Engineer – DaaS / APIs / MCP

WHO ARE WE

Cognism is the leading provider of European B2B data and sales intelligence. Ambitious businesses of every size use our platform to discover, connect, and engage with qualified decision-makers faster and close more deals. Headquartered in London with global offices, Cognism’s contact data and contextual signals are trusted by thousands of revenue teams to eliminate the guesswork from prospecting.

About Cognism

Cognism is building Europe's leading B2B Sales Intelligence platform. Our engineering organisation is transforming around customer outcomes, data quality and AI-first engineering. The Warsaw Hub is being established as one of Cognism's two primary engineering centres and will play a key role in the company's long-term growth.

About the Role

As a Senior Software Engineer, you will build the services that power Cognism's strategic Data-as-a-Service (DaaS), APIs and Model Context Protocol (MCP) capabilities. You will work on cloud-native distributed systems processing large volumes of business data and exposing it through secure, scalable APIs used by enterprise customers and AI-powered workflows. This role is ideal for engineers who enjoy building high-quality backend systems while owning software throughout its lifecycle.

What You'll Do

Design, build and maintain backend services supporting DaaS, APIs and MCP

Deliver production-ready software with strong focus on quality, reliability and performance

Own features from technical design through deployment and operational support

Collaborate closely with Product Managers, Architects, Platform and Data Engineering teams

Contribute to architectural decisions and continuously improve engineering standards

Write automated tests and participate in code reviews

Use AI-assisted engineering tools to improve development productivity

What Success Looks Like

Deliver strategic platform capabilities on time

Take ownership of production services with measurable reliability improvements

Contribute reusable engineering patterns adopted by multiple teams

Act as a trusted technical mentor for less experienced engineers

Required Experience

5+ years of professional software engineering experience

Strong backend development skills using Java, Scala, Kotlin, C# or modern TypeScript/Node.js

Experience designing REST APIs and distributed microservices

Hands-on knowledge of AWS or another major cloud platform

Experience with SQL and NoSQL databases

Strong understanding of CI/CD, Git and modern software engineering practices

Excellent communication skills and fluent English

Nice to Have

Kafka or event-driven architectures

Kubernetes and Docker

Infrastructure as Code

Experience building public APIs or developer platforms

Experience with AI coding assistants such as Claude Code, GitHub Copilot or Cursor

Why Join Cognism

You will join the founding engineering team of Cognism's Warsaw Hub, helping build a strategic platform that will shape the company's future. You'll work in a modern engineering environment with significant ownership, direct impact on product direction and opportunities to influence architecture, engineering practices and culture from the earliest stages of the hub.

Hiring Process

Recruiter introduction

Hiring Manager interview

Technical coding interview

System design interview

Final leadership conversation

WHY COGNISM

At Cognism, we’re not just building a company - we’re building an inclusive community of brilliant, diverse people who support, challenge, and inspire each other every day . If you’re looking for a place where your work truly makes an impact , you’re in the right spot!

Our values aren’t just words on a page—they guide how we work, how we treat each other, and how we grow together. They shape our culture, drive our success, and ensure that everyone feels valued, heard, and empowered to do their best work.

Here’s what we stand for:

• 🤝 We Own the Outcome Together.
• 🤓 We Deeply Understand our Customers.
• 🏆 We Celebrate Impact Wherever It Comes From.

At Cognism, we are committed to fostering an inclusive, diverse, and supportive workplace. We welcome applications from individuals typically underrepresented in tech, so if this role excites you but you’re unsure if you meet every requirement, we encourage you to apply!