Senior Polyglot Engineer @

2 weeks ago

Warszawa, Mazovia, Czech Republic Winged IT Full time
  • 8+ years of experience with Python, JavaScript/TypeScript, React, and React Native;
  • Experience with Redis and PostgreSQL;
  • Strong emphasis on backend development;
  • Familiarity with AWS services such as DynamoDB, Firehose, and Elasticache;
  • Experience with tools like Datadog and Elasticsearch;
  • Prior experience with Klarna payments API (PACS, OPF, etc.) and understanding of how orders flow through various services from creation to merchant capture;
  • Strong educational background in Computer Science, Information Technology, or a related field;
  • Language proficiency: Advanced English (minimum B2 level).

Nice to have:

  • Experience with payments, remittances, or banking APIs;
  • Klarna experience (or Klarna platform knowledge—e.g. routing layers, service registration, AuthN/AuthZ models);
  • Comfortable contributing to web or app UI codebases (React, React Native).

Do you want to play a key role in revolutionizing the future of finance? Join a global leader in deferred payments, with over 85 million active users and 2.5 million transactions processed daily As a pioneer in modern payment solutions, our client is developing innovative methods that streamline the shopping experience, enhance transaction security, and expand the availability of purchasing options.

We're seeking individuals eager to achieve remarkable results and share their bold vision to redefine the future of payments and fintech. Send us your CV - we can't wait to meet you

Employer: Klarna

Location: Warsaw (hybrid work: 2-3 days in the office)

Rate: 170 - 195 PLN per hour

Cooperation model: B2B or Employment Contract

Start date: ASAP

Duration: long-term agreement

,[To take part in building a cross-platform money movement engine seamlessly connecting Klarna users (and non-users) across markets, currencies (incl. crypto), and payment networks;, To work as a full-stack engineer with strong backend focus;, To build and maintain scalable backend services in Java, Python, and TypeScript;, To develop high-performance APIs powering P2P and cross-border money transfer experiences in Klarna's app and web products;, To design and maintain secure, observable, and fault-tolerant infrastructure;, To own the full development lifecycle—from design to deploy and monitor;, To integrate with third-party money movement APIs (e.g. banking and crypto API providers, banking partners, SEPA, etc.);, To ensure compliance with Klarna's security, identity, KYC, and AML flows;, To build robust and secure payment orchestration and settlement logic;, To work with Klarna-internal teams (e.g. Payments, Identity, Customer Support) to reuse or extend foundational capabilities;, To understand and plug into Klarna's existing infra (e.g. PubSub events, internal auth models, mobile architecture);, To build feature-rich AI powered UIs for chat-based money transfers, payment link generation, FX tracking, and transaction history;, To contribute to UI codebases (TypeScript/React/React Native) as needed.] Requirements: AWS, Python, React, Redis, PostgreSQL, JavaScript, Node.js Tools: Jenkins, Agile. Additionally: Small teams, International projects, Flat structure, In-house trainings, Modern office, Mobile phone, Startup atmosphere.

  • Senior Software Engineer – Python

    4 days ago

    Warszawa, Mazovia, Czech Republic Link Group Full time

    What We're Looking For:At least 5 years of professional experience in software engineeringStrong programming skills in PythonHands-on experience with at least one functional programming language (Haskell, Scala, Clojure, F#, Erlang, etc.)Degree in Computer Science, Mathematics, Physics, or related disciplineFamiliarity with statistical computing, numerical...

  • Senior Data Engineer – Python, Spark, AWS @

    4 days ago

    Warszawa, Mazovia, Czech Republic Link Group Full time

    What We're Looking For:5+ years of experience in Python and strong software engineering skillsSolid knowledge of AWS cloud services and best practicesExperience building scalable Spark pipelines in PySpark or ScalaPractical experience with Spark Streaming for low-latency pipelinesFamiliarity with Delta Lake and modern data lakehouse architecturesHands-on...

  • Senior QA Engineer @

    4 days ago

    Warszawa, Mazovia, Czech Republic ITMAGINATION Full time

    5+ years of experience in manual QA testing  Proven expertise in FX trading platforms and FX protocol  Strong knowledge of BDD, Kibana, and Unix/Linux environments  Proficient with Xray, Jira, and API testing tools (e.g., Postman/Soap)  Experience with basic Bash/CLI, Jenkins, Putty, and WinSCP  Hands-on experience in managing test cases and...

  • Senior Software Engineer in Finance with C# @

    7 days ago

    Warszawa, Mazovia, Czech Republic Link Group Full time

    5+ years of experience in software development, specifically within finance or a similar domain.Advanced proficiency in C# and SQL.Bachelor's degree in Mathematics, Physics, Computer Science, Engineering, Finance, or a related field.Strong problem-solving skills, particularly in complex financial systems and technologies.Excellent communication skills to...

  • Senior Software Engineer in Finance with C# @

    7 days ago

    Warszawa, Mazovia, Czech Republic Link Group Full time

    5+ years of experience in software development, specifically within finance or a similar domain.Advanced proficiency in C# and SQL. Experience in Python or functional programming languages is a big plus.Bachelor's degree in Mathematics, Physics, Computer Science, Engineering, Finance, or a related field.Strong problem-solving skills, particularly in complex...

  • Senior Data Engineer – Advanced Data Solutions

    4 days ago

    Warszawa, Mazovia, Czech Republic beBee Careers Full time

    Key Responsibilities:We are seeking a Senior Data Engineer to join our team responsible for designing and building scalable data ingestion pipelines in AWS. This role is central to integrating modern data lakehouse components and supporting the company's AWS-based infrastructure.Design and build scalable data ingestion pipelines in AWSWork extensively with...

  • Senior MLOps Engineer @

    18 hours ago

    Warszawa, Mazovia, Czech Republic Team Up Recruitment Full time

    RequirementsBachelor's degree in Computer Science or a related fieldMinimum of 5 years of professional experience in designing and building microservices in a production environmentStrong hands-on experience with Infrastructure as Code tools (e.g., Terraform), cloud platforms, and orchestration services such as AWS Sagemaker, Airflow MWAA, Step Functions,...

  • Senior Full Stack Software Engineer

    4 days ago

    Warszawa, Mazovia, Czech Republic beBee Careers Full time

    Job Title: Senior Full Stack Software EngineerAbout the Role:We are seeking a highly skilled and experienced Senior Full Stack Software Engineer to join our team. As a key member of our software development lifecycle, you will be responsible for managing the full development process, from requirements analysis to maintenance.Main Responsibilities:Full...

  • Software Engineering Expert for High-Performance Systems

    3 days ago

    Warszawa, Mazovia, Czech Republic beBee Careers Full time

    Senior Software Engineer – Python & Functional Programming"],

  • Senior Software Engineer

    2 weeks ago

    Warszawa, Mazovia, Czech Republic VISA Full time

    Energy and Experience: A growth mindset that is curious and passionate about technologies and enjoys challenging projects on a global scale.Experience of working with agile methodologies and understand the value of tracking engineering key metricsChallenge the Status Quo: Comfort in pushing the boundaries, 'hacking' beyond traditional solutionsLanguage...