Senior Software Developer – PHP & Java

Project overview

We are looking for an experienced Senior Software Developer for a demanding project in the area of digital certificates and archiving solutions. You will work as a freelancer in a 48-month engagement with 40% utilization.

Your tasks include analyzing existing systems and developing migration strategies for document archives. You will oversee data migration and the decommissioning of old production systems. Furthermore, you will analyze, specify, and implement components and system architectures for solutions in the area of digital certificates. You will evaluate functional and non-functional requirements and develop order management systems for certificate products using agile development methods.

Technologically, you will work with Java, PHP, and MySQL. Programming and system architecture are the focus of your daily work.

We expect at least three years of professional experience in PHP 5 and higher, Java, and in the area of Public Key Infrastructure (PKI). Experience in a Trust Center environment and certified data center operations is required.

Long-term refactoring experience in existing systems, knowledge of SOAP, WSDL, and XSD, as well as experience in developing shop systems and MySQL are advantageous.

The engagement is possible 100% remotely, with an on-site onboarding. The hourly rate is 85 Euros. Start date is December 2026.

Project details

• Start: 12/2026
• Duration: 48 Monate
• Remote: onsite
• Location: Berlin, DE
• Rate: 85-85 EUR/h
• Languages: German