Full Stack Developer

Keystone Solutions; Brussel; Hybrid; EUR 60,000 - 90,000; Full time

Benefits offered by this job

Remote work up to 3 days/week

Long-term renewable contract

Job summary

Keystone Solutions is seeking a Full-Stack Developer for a consultancy mission at a client site in Belgium. You will engage in the entire development cycle for a national border control project, working on the BorderTask ecosystem with both backend and frontend responsibilities.

Requirements include strong PHP expertise, modern JavaScript, and experience with Laravel or Symfony; Vue.js is a plus. You will handle legacy code, implement REST APIs, and ensure security and maintainability.

Qualifications

• Proven experience with Laravel and Symfony in production environments.
• Strong JavaScript skills with modern frameworks.
• Experience with REST APIs, SQL databases, and Git workflows.
• Ability to maintain and evolve legacy PHP applications.
• Security-conscious coding and code quality practices.

Responsibilities

• Design, develop, test, and maintain web applications across the full stack.
• Develop and integrate REST APIs and ensure security and performance.
• Evolve legacy codebases and improve maintainability.
• Collaborate with analysts and project partners to deliver features.
• Participate in code reviews, testing, and documentation.

Skills

PHP

JavaScript

SQL

REST APIs

Tools

Laravel

Symfony

Vue.js

React

AngularJS

CodeIgniter

Smarty

jQuery

PostgreSQL

Docker

GitLab

Job description

Mission Overview

Keystone Solutions is seeking a Full-Stack Developer to join a consultancy mission at a client site. This role involves engaging in the entire development cycle for a national project focused on border control applications.

Project Details

The project involves the BorderTask ecosystem, which includes applications for various modes of transport and border control processes. The applications handle sensitive biometric and alphanumeric data, ensuring compliance with European regulations while providing direct impact on operational efficiency.

Responsibilities

• Design, develop, test, and maintain web applications.
• Handle development across the entire stack, from backend to frontend.
• Develop and integrate REST APIs.
• Understand and evolve existing legacy codebases.
• Participate in securing and modernizing the application.
• Restructure code to improve maintainability and separation of concerns.
• Engage in technical analysis and problem-solving.
• Ensure code quality, stability, and security.
• Participate in code reviews and testing.
• Document development work.
• Collaborate with developers, analysts, and other project partners.

The applications are actively used by law enforcement at border checkpoints, providing immediate feedback on functionality and user experience.

Profile Requirements

• Strong expertise in PHP.
• Good command of modern JavaScript.
• Experience with at least one modern PHP framework, preferably Laravel or Symfony.
• Experience with at least one modern JavaScript framework, with Vue.js being an advantage.
• Ability to work autonomously on both backend and frontend.
• Proficiency in SQL, REST APIs, and Git.
• Comfortable with maintaining and evolving legacy code in production.
• Experience in developing complex applications in production.
• Ability to identify and rectify security issues in existing codebases.
• Knowledge of best development practices: architecture, code quality, security, testing, error management, and maintainability.
• Capable of analyzing complex technical problems and proposing suitable solutions.
• Quickly adapt to existing codebases and become operational.

Technical Environment

• Current Stack: PHP 5.6 / 7.4, CodeIgniter, Smarty, AngularJS, jQuery
• Target Stack: PHP 8.2+, Laravel 12+, JavaScript, Vue 3
• API: REST
• Database: PostgreSQL
• Versioning: Git / GitLab
• Containerization: Docker / Podman
• Servers: Linux / Red Hat Enterprise Linux
• CI/CD: CI/CD practices and tools

Conditions

• Professional English required, both spoken and written.
• Fluency in French or Dutch is acceptable; neither language is prioritized.
• This mission is part of a long-term collaboration, contractually organized in renewable six-month periods.
• Remote work is allowed up to three days a week.
• Use of AI tools is subject to internal policy and security constraints.
• Occasional travel to operational sites is expected.

Advantages

• Proven experience with Laravel and/or Vue.js.
• Experience with Symfony, React, Angular, or equivalent technologies.
• Experience in modernizing legacy applications.
• Good knowledge of application security.
• Experience with critical or high-availability applications.
• Experience in the public sector.

Duration

01/12/2026 - 31/12/2026 5 weeks

• (full time)

Skills required

• JavaScrip - Level: Confirmed - Most recent: Any time
• Laravel - Level: Confirmed - Most recent: Any time
• PHP - Level: Confirmed - Most recent: Any time
• SQL, API REST, Git - Level: Confirmed - Most recent: Any time

Language Requirements

Dutch

Level Active knowledge

English

Level Active knowledge

French

Level Active knowledge