← All jobs
thecodest

Senior Fullstack Engineer (Java&Kotlin + JavaScript)

Remote - Poland
Level
Senior
Work type
Remote · Poland only

Not stated in the posting: salary, visa.

Open. First seen 22 October 2026.

Apply on the company's site →

About the role

thecodest's standard text

🌍 Hello World!

We are The Codest - International Tech Software Company with tech hubs in Poland delivering global IT solutions and projects. Our core values lie in “Customers and People First” approach that prioritises the needs of our customers and a collaborative environment for our employees, enabling us to deliver exceptional products and services.

Our expertise centers on web development, cloud engineering, DevOps and quality. After many years of developing our own product - Yieldbird, which was honored as a laureate of the prestigious Top25 Deloitte awards, we arrived at our mission: to help tech companies build impactful product and scale their IT teams through boosting IT delivery performance. Through our extensive experience with product development challenges, we have become experts in building digital products and scaling IT teams.

But our journey does not end here - we want to continue our growth. If you’re goal-driven and looking for new opportunities, join our team! What awaits you is an enriching and collaborative environment that fosters your growth at every step.

Project description:

Our client is one of the largest e-commerce platforms in Europe, used by millions of users every day. The company connects sellers - from small businesses to global brands - with customers, offering a vast product selection, fast delivery, and a well-crafted shopping experience.

The subject of the contract is the provision of professional services within the New Ventures Core Tech area. This area focuses on launching innovative services with external strategic partners. Under the operational model, external partners predominantly integrate by calling the Purchaser’s APIs.

Engineer in this project will act as a technical leader and the architectural anchor for these integrations.

The role:

  • API Design & Partner Integration: Facilitating seamless onboarding of external partners by designing robust API contracts, writing high-quality developer documentation, and creating mock environments.
  • Frontend Development: Driving the development of modern web interfaces (including checkout paths, landing pages, and discovery hubs) that consume the integrated partner services.
  • Technical Leadership: Bridging Java and Kotlin backend design with modern frontend development to ensure cohesive, end-to-end technical implementation.
  • Deep, hands-on experience in Java and Kotlin.
  • Strong track record in designing, building, and scaling RESTful APIs (API-first design, OpenAPI/Swagger).
  • Excellent frontend skills: proficiency in moder JavaScript/TypeScript and a modern framework (React is highly preferred).
  • Solid understanding of distributed systems, integration patterns, and secure authentication (OAuth 2.0, OpenID Connect).
  • Proven ability to define coding standards, lead technical discussions, and design flexible "API contracts" for external B2B partners.
  • English level min. B2+
  • Availability for the Incident Response service.

Nice to have:

  • Experience dealing with data isolation and security standards
  • Eagerness to explore and implement Agentic AI tools (e.g., Copilot, LangGraph) to accelerate engineering workflows.

Our offer:

  • 20–26k PLN on a B2B contract
  • Access to the Worksmile platform
  • A work environment that values growth and innovation - you bring the ideas, and we want to hear them 😉

Recruitment process:

  • 30-minute screen with our recruiter, Justyna
  • Technical Verification Meetings
  • Stakeholder meeting
  • Offer
thecodest's standard text

Questions, insights? Feel free to reach out to our recruiting team:

justyna.pazdalska@thecodest.co

In the meantime, feel free to visit our website where you can find key facts about us.

What this role asks for

Particular to this role

LangChain · OAuth · OpenAPI

Rare in thecodest's other 22 open postings.

Standard for mobile roles

Kotlin

Common in mobile postings at any company.

62% of this description is written for the role. The rest is thecodest's standard text, folded away below.

Compared with thecodest's other open jobs.

The team: Development HIRES STEADILY

This role is one of 21 open in Development. 4 were posted in the last 30 days and the oldest in May: a team that hires all year rather than one being built.

WHAT THE TEAM WORKS WITH, ACROSS ITS POSTINGS

CI/CD (14 of 21), Python (10 of 21), REST (10 of 21), Java (9 of 21), JavaScript (8 of 21), React (8 of 21), AWS (7 of 21)

OTHER ROLES ON THIS TEAM

From the team and dates on thecodest's own job board.

Similar jobs

Is this your posting? Email info@careerholo.com to have it removed.