Senior Fullstack Developer (PHP+React)

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

About SINGU

At SINGU, we’re redefining how the world’s most ambitious real estate companies run their operations. Our mission is to become Europe’s leading platform for managing warehouse, logistics, retail, and multi-site commercial real estate portfolios — empowering our Clients to protect revenue, boost efficiency, and unlock new value across every aspect of their business.

Our unified CAFM platform already powers the daily operations of over 250 million m² of real estate worldwide, supporting more than 500,000 professionals. Following our union with the UK’s Micad and Germany’s net-haus, we now help manage 100,000+ buildings across 35+ countries — and we’re just getting started.

Backed by a leading growth equity investor, we’re scaling rapidly and partnering with global leaders such as Prologis, ECE, CTP, Hillwood, Logicor, GLP, and Unibail-Rodamco-Westfield. As we continue to grow through strategic acquisitions and bold innovation, we stay true to our core values: adaptability, collaboration, and client focus.

If you’re ready to help build Europe’s leading platform for property operations — and make a tangible impact on how the real estate industry works — join SINGU and be part of this transformation.

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