Blockchain Payments Integration - Backend Engineer (TypeScript)

🏢 Summary: Backend Engineer role focused on designing and scaling real-time, cloud-based systems and APIs for an AI-powered consumer product. The position involves building reliable backend services, data pipelines, and infrastructure on AWS within a high-performing engineering team. You will collaborate with mobile and AI teams to deliver low-latency, scalable, and secure user experiences. 🗂️ Requirements: 2+ years backend development experience with Node.js and TypeScript, Strong knowledge of PostgreSQL including schema design and query optimization, Experience with Redis for caching and queue management, Hands-on experience with AWS services (EC2, RDS, Lambda, ECS, S3), Strong REST API design skills and real-time communication patterns, Understanding of scalability, concurrency, and distributed systems, Experience with Docker, Git workflows, and CI/CD automation, Knowledge of backend security and performance best practices 📃 Skills: Node.js, TypeScript, PostgreSQL, Redis, AWS, EC2, RDS, Lambda, ECS, S3, REST, WebSockets, SSE, Docker, Git, CICD 🏢 Description: Backend Engineer – Node.js, TypeScript, AWS For our client, a fast-growing team building a next-generation AI-powered consumer product, we are looking for an experienced Backend Engineer to help scale the systems powering real-time experiences, cloud synchronization, and intelligent APIs. This is not a founding role, but it is a highly impactful engineering position within a small, high-performing team focused on building world-class consumer technology products. About the role You will be responsible for designing, building, and scaling backend systems that support core product functionality — from real-time data pipelines to reliable cloud infrastructure and low-latency APIs. You’ll work closely with mobile and AI teams to deliver fast, scalable, and highly reliable user experiences. Responsibilities Backend Development Design and build RESTful APIs using Node.js and TypeScript (Express.js or Nest.js) Architect and maintain PostgreSQL databases, including schema design and query optimization Implement background jobs and queue systems using Redis for ingestion, summarization, and notifications Build and maintain caching layers (Redis, CDN, HTTP cache) to ensure low-latency performance Implement authentication, authorization, and data privacy best practices Add real-time capabilities using WebSockets and Server-Sent Events Build observability into services through logging, metrics, and tracing Deploy and manage backend services on AWS (EC2, ECS, RDS, S3, Lambda) Systems & Architecture Design clean, scalable, and maintainable service architectures Plan and execute safe database migrations and schema evolution strategies Ensure consistency and reliability across distributed systems Optimize system performance across I/O, CPU, and memory bottlenecks Build and maintain CI/CD pipelines and release automation workflows Contribute to infrastructure reliability, scalability, monitoring, and cost optimization Quality & Security Write unit, integration, and contract tests with clear quality standards Enforce linting, type safety, and static analysis within CI pipelines Conduct security reviews and dependency audits while following least-privilege principles Clearly document services, APIs, and important architectural trade-offs Requirements Must-have 2+ years of backend development experience with Node.js and TypeScript Strong understanding of PostgreSQL, including schema design, indexing, and query optimization Experience working with Redis for caching and queue management Hands-on experience with AWS services such as EC2, RDS, Lambda, ECS, and S3 Strong API design skills, including REST and real-time communication patterns Solid understanding of scalability, concurrency, and distributed systems Experience with Docker, Git workflows, and CI/CD automation Familiarity with security and backend performance best practices Nice to have Experience with GraphQL or gRPC Exposure to event-driven architectures or microservices Familiarity with observability tools such as OpenTelemetry, CloudWatch, or Sentry Experience building high-traffic consumer applications Example stack Backend: Node.js, TypeScript (Express.js / Nest.js), PostgreSQL, Redis Cloud: AWS (EC2, RDS, Lambda, ECS, S3, CloudWatch) Infrastructure: Docker, GitHub Actions, CI/CD

🏢 Summary: Fullstack Developer role focused on building and maintaining backend services in Node.js and frontend applications in React/Next.js, with occasional involvement in smart contract development. The position involves working with databases, APIs, and collaborating across backend and blockchain teams in an onsite environment. The offer is targeted at senior-level engineers with strong production experience. 🗂️ Requirements: Strong Node.js/NestJS backend experience, Minimum 5 years of backend development experience, Minimum 2 years maintaining production applications, Strong React and TypeScript skills, Experience with database and API integration, Ability to work onsite in Warsaw (100%), English level B2 or higher 📃 Skills: Node.js, NestJS, Express, React, Next.js, TypeScript, PostgreSQL, MongoDB, API, EVM, SVM 🏢 Description: About BlockyDevs We build end-to-end applications combining fintech-grade reliability with Web3 innovation. Your Role As a Fullstack Developer, you’ll primarily work with Node.js on the backend, React on the frontend, and occasionally contribute to smart contract development. Responsibilities Develop backend services with *Node.js (NestJS/Express)** Build frontend apps with *React/Next.js + TypeScript** Work with databases (PostgreSQL, MongoDB) and APIs Occasionally contribute to smart contracts (EVM/SVM) Collaborate with design, backend, and blockchain teams Requirements Strong backend skills in Node.js/NestJS At least 5 years of experience in backend applications At least 2 years of experience in maintaining production applications Solid frontend skills in React + TypeScript Database and API integration knowledge Experience mentoring mid/junior developers English at least B2 level Ability to work 100% onsite from our office near Metro Plac Wilsona, Warsaw Nice-to-have Microservices and cloud deployment experience Web3 integrations knowledge Rates (B2B/Freelance) Senior: 120 - 180 PLN/h Recruitment Process 1. Intro Call (30 min) – Quick chat about your experience, expectations, and our projects. 2. Technical Interview / Task – Backend (Node.js) and frontend (React) focus, with some discussion of smart contracts. 3. Final Meeting – Culture/fit + project discussion. 4. Offer – Fast decision if it’s a match. 5. Process usually takes 2–3 weeks . 6. Feedback after each stage within a few days

🏢 Summary: 12-month B2B contract for experienced Backend Developers to build new features and products for a flagship Cashback/Loyalty application in a fast-paced Agile environment. The role focuses on highly scalable, high-load systems using a modern JavaScript stack, fully remote with required overlap with US teams (2pm–10pm CET). 🗂️ Requirements: 5+ years of experience with Node.js (backend), Strong experience with TypeScript, Strong experience with PostgreSQL, Experience with scalable, event-driven architectures, Availability to work 2pm–10pm CET 📃 Skills: Node.js, TypeScript, PostgreSQL, JavaScript, React, ReactNative, GCP, Redis, Docker, Kafka, GraphQL, Apollo, CI/CD 🏢 Description: Our client - a fast-growing US-based fintech - is looking to hire 2 strong Backend Developers to help on an initial 12-month B2B contract, to work remotely. You will be working in an Agile team, dedicated to working on new features and products related to the companies flagship Cashback / Loyalty application. This will be a dynamic and fast-paced enviromnet, working on highly scalable architectures and high load / high transaction databases in a modern JavaScript environment. You must be comfortable working from 2pm-10pm CET, in order to have full consistency with the US teams. Requirements: 5+ years of experience working with Node.JS (Backend) Strong experience with Typescript Strong experience with PostgreSQL Familiarity with scalable, event-driven architectures Some experience in fintech environment is nice to have, but not mandatory Experience with the following is not necessary , but are part of the wider tech stack and so any supplementary knowledge could be helpful: React Native, React.js, GCP, Redis, Docker, Apache Kafka, Apollo GraphQL, CI/CD tool

🏢 Summary: Long-term remote contract for a Senior Frontend-focused Fullstack Developer to support modernization of international money transfer systems in online and mobile banking. The role centers on building modern Angular interfaces while contributing to Java-based microservices and ensuring quality through testing. You will work within a complex banking ecosystem delivering clean, scalable end-to-end solutions. 🗂️ Requirements: Senior-level experience, Strong expertise in JavaScript, Strong expertise in TypeScript, Strong expertise in Angular, Solid experience with Java, Experience with Spring, Experience with Spring Boot, Experience with OR-Mappers, Knowledge of relational databases, Experience with microservices architecture, Proficiency in Clean Code principles 📃 Skills: JavaScript, TypeScript, Angular, Java, Spring, SpringBoot, Hibernate, SQL, Microservices, CleanCode 🏢 Description: Join a major modernization initiative within a leading German bank, focusing on international money transfers for both Online Banking and Mobile Banking (BankingApp). You will collaborate with an existing nearshore team that is highly flexible—developing frontends while also building and testing (manually and automatically) Java-based microservices. We are looking for a specialist who can bridge both worlds but maintains a strong primary focus on the Frontend . Details Start: June 2026. Duration: longterm Location: 100% remote (max. 2 site visits per year to Germany, travel costs covered by the Bank). Workload: 1 FTE Languages: Fluent English is a must; German is a "nice to have." Responsibilities Frontend Development: Leading the creation of modern, responsive interfaces for banking applications using Angular. Backend Support: Building and maintaining backend microservices to ensure end-to-end functionality. Quality Assurance: Participating in both automated and manual testing of the developed services. Modernization: Implementing clean, scalable code within a complex international banking ecosystem. Requirements Frontend (Primary): Strong expertise in JavaScript, TypeScript, and Angular . Backend (Fullstack): Solid experience with Java, Spring, Spring Boot , and OR-Mappers (e.g., Hibernate). Databases: Practical knowledge of relational databases and microservices architecture. Standards: Proficiency in Clean Code principles. Seniority: Senior-level experience is required. Nice to Have Experience with Kafka and Openshift .

🏢 Summary: Entry-level Backend Engineer role focused on supporting the development of backend services and REST APIs under senior guidance. The position involves contributing to production systems, writing tested and maintainable code, and collaborating within a cross-functional engineering team. Ideal for candidates with foundational Java experience seeking hands-on experience in scalable and secure systems. 🗂️ Requirements: Bachelor's degree in Computer Science or related field (or currently pursuing), Minimum 0.5 years of Java experience, Practical experience with RESTful APIs, Ability to work with HTTP methods, status codes, and JSON, Experience writing SQL queries (SELECT, JOIN, WHERE, GROUP BY) or using ORM, Basic understanding of SQL and NoSQL differences, Knowledge of data structures and algorithms, Ability to use Git in a team environment (branching, pull requests, merge conflicts), Experience writing unit tests, Experience contributing code to production through review and deployment process 📃 Skills: Java, REST, HTTP, JSON, SQL, NoSQL, ORM, Git, JUnit, Pytest, Jest, CI, Algorithms, DataStructures, APIs, Testing 🏢 Description: (5190) About This Role You will be a part of the Engineering team and reports to our Manager, Engineering. You will support the development of backend services and APIs that power customer’s products. Working under close guidance from experienced engineers, you will gain hands-on experience contributing to real-world systems while learning best practices in software development, scalability, and security. Key Responsibilities Support the development of backend services and APIs under direct supervision of senior engineers Assist with writing clean, maintainable, and well-documented code following team standards Help debug, test, and troubleshoot backend systems and services Contribute to small tasks or components within larger projects Collaborate with cross-functional teams including Frontend, Product, and DevOps Participate in code reviews and apply feedback to improve technical skills Assist in writing unit tests and validating functionality Document technical processes and development work Required Qualifications Bachelor's degree in Computer Science or a related field; Currently pursuing is also an option Strong theoretical knowledge of Java, at least 0.5 years of experience Practical experience building and consuming RESTful APIs — HTTP methods, status codes, JSON, request/response handling, basic error handling. Working knowledge of databases — has written real SQL queries (SELECT, JOIN, WHERE, GROUP BY) or used an ORM in production code; understands the difference between SQL and NoSQL at a basic level. Solid understanding of data structures and algorithms — arrays, hash maps, trees, basic Big-O analysis — sufficient to discuss simple coding problems and reason about correctness. Comfortable with Git in a team setting — branching, pull requests, code review, addressing feedback, resolving merge conflicts; has worked in a shared repository with at least one other developer. Hands-on experience writing unit tests for their own code (pytest, JUnit, Jest, or equivalent), and basic familiarity with how testing fits into a CI pipeline. Demonstrated ability to ship code to production — even small features or bug fixes — through a real review and deployment process; ability to clearly describe what they built, how it was reviewed, and how it was tested. Genuine interest in cryptocurrency, blockchain, or Web3 (self-taught is fine — owning crypto, reading, side projects, hackathons) and willingness to learn the regulated FinTech context; English level: Upper-intermediate or higher, sufficient for daily team communication and code review discussions. Bonus: exposure to Linux / command line, Docker basics, message queues (Kafka, RabbitMQ), cloud platforms (AWS, GCP), open-source contributions, hackathon participation, or an active public GitHub portfolio.

🏢 Summary: Senior Fullstack TypeScript Engineer role in a fintech environment focused on building and maintaining scalable, secure full-stack applications with a backend emphasis (Node.js) and React frontend. The position involves system and API design, real-time components, testing, and production support, using modern engineering practices including AI-assisted development. It is a hands-on role centered on architecture quality, performance, and reliable delivery. 🗂️ Requirements: Strong experience with Node.js, TypeScript, JavaScript (ES6+), React, Experience building full-stack web applications, Solid understanding of REST APIs and authentication, Knowledge of scalable system design (stateless services, caching, queues, performance), Experience with relational databases (PostgreSQL or MySQL), Experience with unit, integration, and E2E testing, Understanding of performance optimisation and debugging, Ability to evaluate technical trade-offs and system design decisions, Experience using AI tools in development workflows with critical validation of outputs, Professional English proficiency 📃 Skills: TypeScript, Node.js, JavaScript, React, REST, PostgreSQL, MySQL, SQL, Testing, CI/CD, Authentication, Caching, Queues, AI, Git, HTML, CSS 🏢 Description: Senior Fullstack TypeScript Engineer – Fintech London / Remote | B2B | Competitive package Our client is a UK-based fintech company with 25+ years of experience delivering innovative solutions for repo and securities financing markets. Their platform connects major market participants and provides real-time services that enable efficient and accurate trading. We are looking for a Senior Fullstack TypeScript Engineer to join our client’s engineering team. This role has a strong backend focus (approximately 60% backend / 40% frontend) and involves working across both frontend and backend systems, contributing to scalable architecture, feature delivery, and engineering best practices. This is a hands-on, delivery-focused role with a strong emphasis on system design, quality, and modern engineering practices, including AI-assisted development workflows. Responsibilities Build and maintain Fullstack applications using TypeScript (Node.js + React) Design and implement features across frontend and backend systems Participate in API and system design discussions Contribute to decisions around REST APIs, authentication, and architecture patterns Build secure, scalable, and maintainable systems Work with real-time and event-driven components where applicable Write and maintain unit, integration, and end-to-end tests Support production systems and assist in incident resolution when needed Participate in code reviews and contribute to engineering standards Use AI-assisted tools (e.g., Cursor, GitHub Copilot) to improve productivity, debugging, testing, and refactoring, while critically validating outputs Requirements Strong experience with Node.js, TypeScript, JavaScript (ES6+), React Experience in building full-stack web applications Solid understanding of REST APIs, authentication, and API design Knowledge of scalable system design (stateless services, caching, queues, performance) Experience with relational databases (PostgreSQL / MySQL) Experience with testing (unit, integration, E2E) Understanding of performance optimisation and debugging Ability to evaluate technical trade-offs and system design decisions Experience working in agile, collaborative teams Strong communication and ownership mindset English – professional working proficiency AI & Engineering Mindset Comfortable using AI tools in daily development work Able to: validate AI-generated code for security, maintainability, and performance use AI for debugging, refactoring, and test generation critically assess outputs instead of blindly accepting suggestions Awareness of secure usage of AI tools and data handling practices Nice to have AWS / cloud experience Docker / Terraform Event-driven architecture GraphQL experience State management (Redux / Zustand) Tailwind / Styled Components Observability (logging, metrics) Load / performance testing Data visualization (D3.js)

🏢 Summary: Short-term B2B contract for a Fullstack Developer (Node.js + TypeScript) to build and maintain backend services for a regulated digital capital market platform in the fintech domain. The role focuses on developing scalable APIs, integrating KYC/AML providers, and implementing authentication, authorization, and investor management features. The project emphasizes code quality, security, and collaboration with cross-functional teams. 🗂️ Requirements: 3+ years commercial experience with Node.js, Strong knowledge of TypeScript, Experience building REST APIs, Experience with NestJS or similar framework, Experience with Prisma ORM or similar ORM, Understanding of authentication and authorization, Experience with relational databases, Experience writing automated tests, Knowledge of clean code principles, English for daily communication 📃 Skills: Node.js, TypeScript, NestJS, Prisma, REST, SQL, Jest, Supertest, Authentication, Authorization 🏢 Description: Description We are a technology company that started its journey in 2008. Our main headquarters is located in the picturesque city of Poznań, nestled by the beautiful Malta lake. For more than 17 years, we have been assisting companies in developing and implementing innovative fintech solutions. Leveraging our expertise in areas such as blockchain, online payments, and more, our clients can invent and develop cutting-edge solutions and services that keep them at the forefront of innovation. FULLSTACK DEVELOPER B2B: 80-100 PLN / hour START - 1 JULY TERM - 6 WEEKS LOCATION: POLAND (REMOTE) *We offer a hybrid work model, allowing you to balance office presence with remote work. However, it's important to note that the role emphasizes a stronger presence in the office to foster teamwork and effective communication. Requirements Key Duties and Services: A Roadmap to Your Professional Success Your Mission : We are looking for a Fullstack Developer (Node. js + TypeScript) to join a fintech project focused on building a regulated digital capital market platform. The system supports investor onboarding, KYC/AML verification, investor classification, access control, audit logging, and digital wallet infrastructure. You will work closely with senior engineers and architects to build scalable backend services and integrations with fintech and blockchain-related providers. Scope of services: Developing and maintaining backend services using Node. js + TypeScript Building and extending REST APIs for onboarding, authentication, and user management Integrating external KYC/AML and identity verification providers Implementing business logic for investor classification and access control Creating and maintaining database models using Prisma ORM Writing unit and integration tests (Jest, Supertest) Participating in code reviews and technical discussions Collaborating with frontend, mobile, QA, and product teams Supporting code quality, security, and system reliability Here’s the set we are required: 3+ years of commercial experience with Node. js backend development Strong knowledge of TypeScript Experience building REST APIs and backend systems Experience with NestJS or similar frameworks Experience with Prisma ORM or similar Understanding of authentication & authorization concepts Familiarity with relational databases Experience writing automated tests (Jest, Supertest or similar) Strong understanding of clean code principles and best practices Good communication skills and English for daily cooperation Nice to have: Experience with class-validator / DTO-based validation Familiarity with GraphQL (Apollo) Experience in fintech / banking / regulated environments Knowledge of KYC/AML processes Exposure to blockchain, wallets, or digital assets Career Advancement at Your Fingertips: Explore Opportunities with Us By joining us you will get: Work on a modern fintech platform with real regulatory requirements Collaboration with experienced senior engineers and architects Opportunity to work with KYC/AML, identity systems, and fintech integrations Influence on system design and backend architecture decision A strong engineering culture focused on quality, security, and scalability Navigating the Hiring Process: What does the recruitment process for that position look like? HR Screening with Talent Acquisition Specialist (30 min) Technical Interview (60 min) Interview with Delivery Manager (30 min) Job Offer

🏢 Summary: Senior Backend Engineer role focused on defining the technical direction and architecture of a domain within a borderless financial platform. The position involves designing scalable microservices, driving architectural decisions, and leading a small backend team in a distributed environment. The role emphasizes reliability, security, and high‑volume transaction processing in a cloud-based ecosystem. 🗂️ Requirements: 4-7 years backend engineering experience, Proficiency in Go, Experience with Java 21 or modern Java, Experience designing microservices with clear contracts, Experience with caching strategies including TTL and invalidation, Experience with event-driven or asynchronous architectures, Experience with structured logging, metrics, and alerting, Experience with AWS services, Experience with relational and non-relational databases, Experience with Spring Boot or similar frameworks, Experience reviewing code and architectural decisions, Availability to work in GMT+5:30 timezone 📃 Skills: Java, Go, Spring, JDBI, PostgreSQL, CockroachDB, DynamoDB, Redis, SQS, SNS, Kafka, AWS, EKS, ALB, RDS, S3, Kong, Datadog, Quickwit, JWT, RBAC, TLS, Docker, ArgoCD, GitHub, Microservices, Kafka, CDC 🏢 Description: Project overview This project focuses on developing a borderless financial platform that supports international banking flows, payments, account management and regulatory compliant operations. The product handles sensitive data and high volume transactions while prioritising reliability and security. Team You will work in a distributed environment with backend engineers, a product manager and platform specialists. The role involves leading a sub team of three to five engineers, conducting design reviews, ensuring code quality standards and supporting collaborative decision making. Position overview We are looking for a Senior Backend Engineer who will define the technical direction of a backend domain and drive architectural decisions. You will design microservices, create scalable solutions, guide a small engineering group and collaborate closely with product specialists to shape the delivery roadmap. We are looking for a person willing to work in the time zone: GMT+5:30. Technology stack Java 21, Go, Spring Boot, JDBI, custom workflow engines, PostgreSQL, CockroachDB, DynamoDB, Redis, SQS, SNS, Kafka, AWS EKS ALB RDS S3 Secrets Manager, Kong API Gateway, Datadog, Quickwit, JWT RBAC TLS request and response encryption VAPT, GitHub Actions, Docker, ArgoCD, microservices, event driven architecture, saga and orchestration patterns, CDC pipelines, maker checker workflows Responsibilities Plan and design backend microservices with clear boundaries and contracts Develop solutions for domains such as onboarding, payments, transaction orchestration or platform components Break complex epics into actionable tasks with clear acceptance criteria Review designs from other engineers to ensure scalability and fault tolerance Drive technical decisions including caching layers, asynchronous processing strategies, database choices and API versioning Evaluate build versus buy options for integrations and services Collaborate with a product manager to align on scope and prioritisation Lead a sub team of backend engineers and support their professional growth Support incident response, root cause analysis and long term improvements Monitor service performance using logging, metrics and tracing tools Requirements Professional backend engineering experience from 4-7 years Experience with Go (tooling & CLIs) Experience designing microservices with well-defined contracts and boundaries Experience with Java 21 or modern Java versions Experience with caching strategy design, including TTL and invalidation approaches Experience working with asynchronous processing, event-driven architecture, or queue-based workflows Experience using structured logging, metrics, and alerting to debug production systems Experience in making build versus buy decisions with clear trade-off analysis Experience reviewing code and identifying architectural or contract issues Experience with AWS-based services Experience working with relational and non-relational databases such as PostgreSQL or DynamoDB Experience writing backend services using Spring Boot or similar frameworks Nice to have Experience with financial or payments related systems Experience with KYC or AML flows Experience with workflow or orchestration engines Experience with platform wide pattern creation or reusable service design Experience with data encryption practices and security audits Experience with CockroachDB or high availability distributed databases What We Offer: Vacation days : Up to 26 business days per year. 10 illness/special days off per year (fully paid, no medical papers needed) for all contract types Health and life insurance (Luxmed) MyBenefit platform with Multisport option Internal psychological support service English language classes from the first working day Access to external learning platforms : O’Reilly, LinkedIn Learning, Udemy, and a wide catalog of diverse internal training Flexible workplace : work from the office, from home, or choose a hybrid option Tech Skills Mentoring Program Opportunities to develop as a public speaker, mentor, or technical interviewer Fully paid idle (bench) when not involved in a project Certification reimbursement (AWS, GCP, Microsoft, etc.)

🏢 Summary: Mid to senior backend engineer role focused on designing and scaling enterprise-grade backend services and integrations using Node.js and cloud-native technologies. The position involves building high-performance APIs, optimizing databases, leading CI/CD and DevOps practices, and mentoring engineering teams in complex enterprise environments. Fully remote opportunity available as full-time or B2B. 🗂️ Requirements: Minimum 5+ years of backend development experience with Node.js, TypeScript, NestJS, Proven experience designing and scaling RESTful APIs and SOAP services, Advanced PostgreSQL administration including performance tuning, replication, partitioning, Strong experience with Git workflows and CI/CD pipelines, Hands-on experience with AWS services (EC2, EKS, Lambda, S3, RDS, CloudWatch, API Gateway), Solid knowledge of Kubernetes deployment and scaling, Experience with monitoring and observability tools, Experience with infrastructure as code tools, Bachelor’s degree in Computer Science, Software Engineering, or related field 📃 Skills: Node.js, TypeScript, NestJS, PostgreSQL, Citus, Patroni, TimescaleDB, REST, SOAP, Swagger, OpenAPI, Postman, Git, GitHub, GitLab, GitHubActions, Jenkins, SonarQube, ESLint, Prettier, AWS, EC2, EKS, Lambda, Fargate, S3, RDS, CloudWatch, APIGateway, Docker, Kubernetes, Helm, Splunk, Prometheus, Grafana, Spinnaker, ArgoCD, AzureDevOps, Terraform, CDK 🏢 Description: We are seeking a mid to senior level engineer with deep expertise in backend engineering, cloud-native architecture, and enterprise system integration. Key Responsibilities Design, develop, and maintain enterprise-grade backend services using Node.js, TypeScript, and NestJS . Architect and implement high-performance REST and SOAP APIs for complex enterprise integrations. Optimize PostgreSQL databases for high availability, partitioning, replication, and performance tuning. Define and enforce secure coding practices, design patterns, and architectural principles . Collaborate with DevOps, frontend, QA, and product stakeholders to ensure seamless integration and delivery. Troubleshoot production issues, enhance reliability, and implement performance tuning at scale. Lead code reviews, enforce coding standards , and integrate quality gates in CI/CD pipelines. Mentor client engineering teams, contribute to technical strategy and architecture decisions . Integrate external systems, tools, and services to extend backend capabilities. Provide continuous innovation by adopting cloud-native, serverless, and emerging backend technologies . Required Qualifications Minimum 5+ years of backend development experience with Node.js, TypeScript, and NestJS. Proven expertise in designing and scaling RESTful APIs and SOAP services for enterprise-grade systems. Advanced proficiency in PostgreSQL administration (performance tuning, replication, partitioning). Strong experience with Git workflows, CI/CD pipelines, and automated quality controls . Deep understanding of cloud-native architectures and serverless implementations . Hands-on experience with AWS services (EC2, EKS, Lambda, S3, RDS, CloudWatch, API Gateway). Solid knowledge of Kubernetes (deployment, scaling, troubleshooting). Experience mentoring teams and driving technical leadership in multi-stakeholder environments . Expertise with Splunk (monitoring, dashboards, alerting). Familiarity with Spinnaker or advanced deployment pipelines . Education Bachelor’s degree in Computer Science, Software Engineering, or related field (required). Master’s degree preferred but not mandatory. Technology / Systems Expertise Node.js + NestJS + TypeScript – backend framework. PostgreSQL with advanced extensions (Citus, Patroni, TimescaleDB). Swagger / OpenAPI + Postman – API documentation & testing. GitHub / GitLab + GitHub Actions / Jenkins – version control & CI/CD automation. SonarQube, ESLint, Prettier – code quality enforcement. AWS (EC2, EKS, Lambda, Fargate, S3, RDS, CloudWatch, API Gateway) – cloud & serverless stack. Docker + Kubernetes (EKS) + Helm – containerization & orchestration. Splunk, Prometheus, Grafana – monitoring & observability. Spinnaker / ArgoCD/ Azure Devops – automated deployment pipelines. Terraform / AWS CDK – infrastructure as code. Skills & Capabilities Demonstrated expertise in backend architecture and scalable API design . Advanced database optimization & high availability strategies . Strong proficiency in CI/CD, GitOps, and DevOps integration . Hands-on experience in cloud-native and Kubernetes-based deployments . Proven ability to mentor engineers, lead architecture decisions, and drive best practices . All our positions are Remote and are available as Full Time Employment or B2B Contracts.

🏢 Summary: Senior Frontend Engineer role focused on building and scaling a modern fintech platform for managing corporate spending. The position involves leading development of React and TypeScript-based SPA applications, integrating with microservices and APIs, and driving performance and architectural improvements. You will collaborate cross-functionally while mentoring engineers and shaping scalable front-end solutions in a cloud-native environment. 🗂️ Requirements: 5+ years professional software engineering experience, Strong commercial experience with React, Strong expertise in TypeScript, Advanced knowledge of modern JavaScript (ES6+), Experience building large-scale SPA applications, Experience designing scalable front-end architectures, Experience working with APIs and microservices-based systems, Hands-on experience with front-end testing (unit, integration, e2e), Experience with CI/CD pipelines, Experience with AWS, Experience with Kubernetes, Professional English proficiency (min. B2), Fluent Polish, Residence in Poland 📃 Skills: React, TypeScript, JavaScript, ES6, SPA, REST, GraphQL, Microservices, CI/CD, AWS, Kubernetes, Testing, SSR 🏢 Description: Join a team building a modern fintech platform that helps businesses manage company spending more efficiently. The project focuses on developing a financial product that enables seamless integration of financial tools—including corporate cards, expense management, and invoice processing—directly with partner ecosystems such as banks, accounting platforms, and HR systems. The platform empowers companies to automate financial operations, simplify reconciliation processes, and gain full real-time visibility into their spending. Your tasks Lead initiatives focused on designing, building, and maintaining scalable front-end applications primarily using React and TypeScript Build modern, performant, and intuitive user interfaces for key areas of the fintech platform Collaborate closely with cross-functional teams across backend engineering, product, and design to deliver scalable product solutions Integrate front-end applications with microservices-based architectures and APIs (REST / GraphQL) Analyze application performance and implement optimizations to ensure high responsiveness, reliability, and scalability Participate in code reviews, architecture discussions, and post-mortems while mentoring other engineers Proactively address technical debt and guide the team through technical challenges, refactoring initiatives, and architectural migrations Requirements At least 5 years of professional software engineering experience, including strong commercial experience with React Strong expertise in TypeScript, modern JavaScript (ES6+), and building large-scale SPA applications Solid experience designing scalable front-end architectures using component-based and modular design principles Experience working with APIs and distributed systems in microservices-based environments Hands-on experience with front-end testing frameworks (unit, integration, e2e) and observability/monitoring tools Previous work with CI/CD pipelines, cloud environments such as AWS, and container orchestration platforms like Kubernetes Strong problem-solving skills, ownership mindset, and passion for mentoring and elevating engineering teams Professional English proficiency - minimum B2 Fluent in Polish required Residing in Poland required Nice-to-have requirements Previous experience in fintech or building financial products Understanding of payments, cards, expense management, or accounting-related domains Experience working in a scale-up environment Experience with GraphQL, SSR, performance optimization, or building design systems What we offer Great Place to Work since 2015 - it’s thanks to feedback from our workers that we get this special title and constantly implement new ideas Employment stability - revenue of PLN 2.1BN, no debts, since 2006 on the market We share the profit with Workers - over PLN 76M has already been allocated for this aim since 2022 Attractive benefits package - private healthcare, benefits cafeteria platform, car discounts and more Comfortable workplace – class A offices or remote work Dozens of fascinating projects for prestigious brands from all over the world PLN 1 000 000 per year for your ideas - with this amount, we support the passions and voluntary actions of our workers Investment in your growth – meetups, webinars, training platform and technology blog – you choose Fantastic atmosphere created by all Sii Power People If you want to work on systems with high operational significance — apply now!