Senior Fullstack Developer (PHP+React)
About The Position
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. The role involves designing and implementing integrations and custom functionality for enterprise clients, building secure, high-performance backend services in PHP, and extending React frontends when the feature needs it. It also includes designing and optimizing data import/export processes with a focus on security, data integrity and performance, finding and removing performance bottlenecks in application and database layers, and taking part in technical breakdown and estimation before development starts, co-owning API contracts. The role also involves reviewing code and mentoring mid-level developers, and being a go-to person for backend and database topics. Collaboration with the Tech Lead, QA, and other SINGU teams (Platform, Core) is expected. This role offers real integrations with enterprise systems, direct impact on systems used daily by some of the largest companies in Europe, senior influence where your technical opinion shapes how the team builds, and a team that values clean code, security, and performance.
Requirements
- 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
- 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 Haves
- 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
Responsibilities
- 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)
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What This Job Offers
Job Type
Full-time
Career Level
Senior
Education Level
No Education Listed
