Senior Fullstack Developer

About SINGU SINGU is one of the fastest-growing PropTech companies in Europe. Our platform manages over 200 million sqm of commercial real estate for 500+ clients in 35 countries, helping property managers digitalize and automate their operations. About the Team The TAM (Technical Account Management) team delivers customizations, dedicated functionality and system integrations for our largest enterprise clients - international leaders such as Prologis, P3, CTP and AmRest. A significant part of the work is data imports/exports and integrations with external systems (ERP, HR, finance, SSO), where security, data correctness and database performance are critical. Customizations must fit into a shared, multi-tenant product - so design quality matters as much as delivery speed. Tech Stack Backend: PHP 8 (Phalcon), REST APIs, Redis, background job queues Database: PostgreSQL Frontend: React (TypeScript) Tooling: Git (Git Flow), Docker, CI/CD, PHPUnit, PHPStan AI-assisted development: Claude / Cursor / Copilot are part of our daily workflow What You’ll Bring Must-have 5+ years of commercial PHP backend development (7.4+/8) Expert PostgreSQL - query optimization, indexing, execution plans, migrations on large datasets Proven experience designing and maintaining REST APIs Hands-on experience with data import pipelines and external system integrations (files, APIs, queues) - idempotency, validation, error handling, reprocessing Working React knowledge - you can deliver a feature end-to-end when needed, not only read the code Strong focus on security (secure coding, access control, data protection) and performance of high-volume operations Full ownership of delivered solutions - from technical design to production and support Experience mentoring other developers and doing meaningful code reviews You actively use AI tools (Claude, Cursor, Copilot, ChatGPT) in your daily work Communicative English (B2+) - technical specs, tickets, documentation; occasional calls with client technical teams Fluent Polish - the team works in Polish internally Nice to Have Phalcon framework PostgreSQL tuning (partitioning, vacuum, planner) and performance troubleshooting in production ERP / enterprise integrations (SAP, Dynamics, PeopleSoft), SSO (SAML / OIDC) Docker, AWS, CI/CD Customization-heavy or multi-tenant B2B SaaS background Improving test automation and local development environments What You’ll Do Design and implement integrations and custom functionality for enterprise clients Build secure, high-performance backend services in PHP, and extend React frontends when the feature needs it Design and optimize data import/export processes with focus on security, data integrity and performance Find and remove performance bottlenecks in application and database layers Take part in technical breakdown and estimation before development starts; co-own API contracts Review code and mentor mid-level developers; be a go-to person for backend and database topics Collaborate with the Tech Lead, QA, and other SINGU teams (Platform, Core) Why This Role Real integrations with enterprise systems - not toy projects Direct impact on systems used daily by some of the largest companies in Europe Senior influence: your technical opinion shapes how the team builds A team that values clean code, security and performance