Web 3 Back-End Software Engineer

SHIMI Sp. z o.o.

• Diploma in IT, Engineering, Mathematics, or Physics.
• 5 years experience in software engineering including full-stack/backend/frontend/distributed systems.
• 5 years experience in scalable, secure, cloud-based software architecture.
• 5 years experience with Agile / Scrum delivery.
• 3 years experience with DID and W3C Verifiable Credential solutions.
• 3 years experience with OpenID4VCI and OpenID4VP.
• 3 years experience with credential issuance, presentation, verification, wallet integration.
• 3 years with cryptographic workflows, digital signatures, secure key management.
• 3 years experience with blockchain-based and distributed-ledger solutions.
• 3 years experience with code reviews and software engineering best practices.
• 3 years experience with Digital Product Passport solutions.
• 5 years experience with JavaScript, TypeScript, React, Next.js, React Native, HTML5, CSS3, Webpack, Vite.
• 5 years experience with Node.js, NestJS.
• 5 years experience with RESTful APIs, OpenAPI, PostgreSQL, MySQL, MongoDB.
• 3 years experience with Solidity, Hardhat, Foundry, OpenZeppelin, ethers.js, token standards.
• 3 years with DID, VC, SD-JWT VC, OpenID4VCI, OpenID4VP, SIOP v2, OAuth2, OIDC.
• 3 years with ECDSA, hardware wallets, digital signatures.
• 3 years with EBSI ecosystem.
• 3 years with XML, XSD, JSON, JSON Schema, JSON-LD.
• 5 years experience with web application security, API protection, OAuth, OWASP.
• 5 years experience with Docker, Kubernetes, GitLab CI, Jenkins, ArgoCD, Git, AWS, Azure, DevSecOps, JIRA, Confluence.
• Minimum English proficiency at B2 level.

• Development of back-end website applications.
• Integration of user-facing elements developed by frontend developers with server-side logic.
• Implement core business logic.
• Design and implementation of data storage solutions.
• Apply data and security best practices: input validation, authentication/authorisation, secure storage, compliant logging and monitoring.
• Optimisation of the application for maximum speed and scalability.
• Design and develop APIs.
• Participate in the design and creation of scalable software.
• Maintenance of code integrity and organisation.
• Writing clean, functional code on the backend.
• Compile and analyse data, processes, and code to troubleshoot problems and identify areas for improvement, including setting up and querying monitoring tools.
• Perform unit/integration testing, debug, fix, and validate code changes.
• Deliver solutions that fulfil functional and non-functional requirements and align with user expectations.
• Write technical documentation.
• Basic configuration of cloud services for back-end functionality (e.g., serverless functions, storage accounts, managed Kubernetes).
• Develop and maintain services and business logic using one or more back-end programming languages.
• Implement authentication and authorization mechanisms to secure API endpoints and services.
• Write and maintain unit and integration tests to ensure code quality and reliability, integrating them into the CI/CD pipeline.
• Plan, execute, and control projects by managing scope, schedule, budget, risks, and stakeholders with recognised methods.

Services must be performed from within the EU. Occasional travelling to Brussels may be required with 7 days’ notice at contractor’s cost.