Medior PHP Backend Developer

Shiftbase; Zoetermeer; On-site; EUR 70,000 - 95,000; Full time

Job summary

Shiftbase is a Netherlands-based workforce software company seeking a backend engineer to join a seven-person backend group. You will work on a platform serving hundreds of thousands of users daily, currently modernizing with Symfony, hexagonal architecture, DDD, and OpenAPI.

You will help shape the system, mentor peers, and leverage AI tooling to push for high-quality, scalable engineering. You’ll collaborate with senior engineers, write clean code, and own meaningful features end-to-end while

Qualifications

• 3–5 years of professional backend experience.
• Proficient in PHP and comfortable with Symfony or a similar framework.
• Solid experience with relational databases and RESTful APIs.
• Familiar with SOLID, clean architecture, or domain-driven design.

Responsibilities

• Build and ship backend features that directly impact users.
• Improve performance, reliability, and scalability of existing systems.
• Break down complex problems into well-structured, testable solutions.
• Drive modernization: refactoring legacy code safely and pragmatically.
• Design and optimize relational database queries and data models.
• Participate in code reviews, architecture discussions, and technical decision-making.
• Use AI development tools as part of daily workflow.
• Mentor junior developers and share knowledge within the team.

Skills

PHP

Symfony

REST APIs

Relational DBs

GIT

CI/CD

Automated tests

OOP SOLID

DDD

Tools

OpenAPI

Claude Code

Job description

About Shiftbase

At Shiftbase, we build workforce software that helps people get work done. Thousands of teams across Europe rely on our platform every day to plan work, track time, and manage leave. We reduce admin so businesses can focus on what really matters.

About Shiftbase

At Shiftbase, we build workforce software that helps people get work done. Thousands of teams across Europe rely on our platform every day to plan work, track time, and manage leave. We reduce admin so businesses can focus on what really matters. Our engineering team is 18 people, a mix of cultures and backgrounds, working in an open team culture where ideas travel freely regardless of title.

About The Role

You'd join a backend group of 7 engineers, most of them senior, working on a platform that serves hundreds of thousands of users daily. This is not a greenfield project. Our codebase has real history and real complexity. We're actively modernizing it: migrating to Symfony, implementing hexagonal architecture, using DDD principles, running on GCP with Kubernetes and Flux, and generating API contracts with OpenAPI. You'll help drive these improvements and take ownership of meaningful parts of the system. The domain is complex. Workforce management touches scheduling, time tracking, leave policies, and labor law across multiple countries. Even our senior engineers take time to fully understand it. If that kind of depth excites you rather than intimidates you, keep reading.

What makes this role different

You'll deepen your engineering craft, not just write code.Yes, we use PHP (latest version) with Symfony. But the real value here is applying and sharpening your skills in OOP, SOLID, Hexagonal Architecture, and Domain-Driven Design. These are transferable principles that make you a strong engineer in any language or stack. You'll be part of an experienced team that values quality.You'll collaborate closely with senior engineers through meaningful code reviews, architectural discussions, and pair programming. You'll also be in a position to mentor less experienced developers and help raise the bar across the team. You'll work with AI tooling that most companies won't adopt for years.We're heavily invested in AI-assisted development. Everyone has access to the latest models. We use Claude Code as our primary tool, we're building spec-driven development workflows, and we're targeting 80% AI-generated code. You'd be developing software in a way that will define how engineering works going forward.

Your first 90 days

We have a structured 30/60/90 onboarding plan. You'll get a buddy, guided first work items, and the context you need to start making an impact quickly. By the end of your first quarter, you'll own features end to end and contribute to technical decisions within the team.

What you'll do

• Build and ship backend features that directly impact users
• Improve performance, reliability, and scalability of existing systems
• Break down complex problems into well-structured, testable solutions
• Drive modernization efforts: refactoring legacy code safely and pragmatically
• Design and optimize relational database queries and data models
• Participate actively in code reviews, architecture discussions, and technical decision-making
• Use AI development tools as part of your daily workflow
• Help mentor junior developers and share knowledge within the team

Career growth

We use a skill matrix to plot a clear development path, including personal goals you set yourself. You'll have regular growth conversations and a concrete picture of what you're working toward. This role is a strong stepping stone toward a senior engineering position.

Who are we looking for

People who are genuinely curious. Who constantly come with ideas to improve things. Who want to try new approaches and aren't afraid to challenge the status quo. Who find satisfaction in making a complex system better over time.

You might be a great fit if:

• You have a few years of professional experience in backend development (roughly 3–5 years)
• You're proficient in PHP and comfortable working with Symfony or a similar framework
• You have solid experience with relational databases and RESTful APIs
• You're familiar with principles like SOLID, clean architecture, or domain-driven design — and you actively try to apply them
• You're comfortable with Git, CI/CD pipelines, and writing automated tests
• You take ownership of your work and proactively propose improvements - You're curious about how systems work under the hood and always looking to grow

It helps if you've worked with AI development tools, contributed to modernization or migration projects, or have experience with event-driven architectures or cloud infrastructure. Note: Candidates outside the Netherlands will not be considered