Senior PHP & React Engineer - Enterprise Integrations

SINGU; Kraków, Warszawa; On-site; PLN 180,000 - 250,000; Full time

Job summary

SINGU in Kraków, Poland, seeks a Senior PHP Backend Engineer to own, design, and deliver secure, high‑volume backend services and API integrations for major real estate clients. You’ll work across data pipelines, system integrations, and React frontends when needed.

Ideal candidates bring 5+ years’ commercial PHP experience, deep PostgreSQL expertise, and a track record of mentoring peers. The role emphasizes security, performance, and end‑to‑end ownership in a multi‑tenant environment.

Qualifications

• 5+ years of commercial PHP backend development (7.4+/8)
• Expert PostgreSQL - query optimization, indexing, 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)
• Working React knowledge - feature end-to-end delivery
• Strong focus on security and high-volume performance
• Full ownership of delivered solutions from design to production
• Experience mentoring other developers and code reviews
• Active use of AI tools (Claude, Cursor, Copilot, ChatGPT)
• Communicative English (B2+) for specs and tickets
• Fluent Polish for internal teamwork

Responsibilities

• Design and implement integrations and custom functionality for enterprise clients
• Build secure, high-performance backend services in PHP, and extend React frontends when needed
• 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)

Skills

PHP backend

PostgreSQL

REST APIs

Data import

React

Security

Performance

Mentoring

AI tools

English (B2+)

Polish

Code reviews

Tools

Git

Docker

CI/CD

PHPUnit

PHPStan

Job description

SINGU in Kraków, Poland, seeks a Senior PHP Backend Engineer to own, design, and deliver secure, high‑volume backend services and API integrations for major real estate clients. You’ll work across data pipelines, system integrations, and React frontends when needed.

Ideal candidates bring 5+ years’ commercial PHP experience, deep PostgreSQL expertise, and a track record of mentoring peers. The role emphasizes security, performance, and end‑to‑end ownership in a multi‑tenant environment.