Senior Software Developer Java / PHP (m/f/d) – PKI & Trustcenter Environment

Project overview

For a current project with a client, we are looking for a developer (m/f/d) to take on tasks related to the replacement of an existing electronic archiving system, including the migration of documents to a new system and further development of solutions for digital certificates. The developer should possess the following qualifications and skills:

Responsibilities

Mandatory Criteria – all must be met for consideration:

Desirable – significantly improves chances:

Application deadline: Monday, November 16, 2026, 2:00 PM. Due to short offer deadlines, later applications unfortunately cannot be considered.

Please submit with your application.

• Analysis of the existing system and development of a migration concept for the documents
• Support of data migration and decommissioning of the old production system
• Analysis, specification, conception, and realization of components and system architectures in the area of digital certificates
• Evaluation and refinement of functional and non-functional requirements
• Conception and development of order management systems for certificate products (agile)
• Programming in Java, PHP, and MySQL
• At least 3 years of experience in PHP (version 5 or higher)
• At least 3 years of experience in Java
• At least 3 years of experience in PKI (Public Key Infrastructure)
• At least 3 years of experience in a trustcenter environment (certified data center operation)
• German at C2 level or native speaker
• English at least B2
• General degree
• Three personal reference projects from the last 48 months (i.e., since November 2022), each lasting at least 3 months. Criteria 1 to 4 must be demonstrable from these three references combined.
• Availability from December 2026 and activity from Germany
• Many years of experience in refactoring legacy systems
• Experience with SOAP, WSDL, and XSD
• Experience in developing shop systems
• Experience with MySQL
• Advantageous: document or archive migration, order management

Project details

• Start: December 2026 (at the latest beginning of January 2027)
• Duration: until December 2028
• Scope: approx. 150 person-days over the entire duration, on-demand (not full-time)
• Location: predominantly remote; personal appearance in Berlin at the beginning and end of the project (hardware issuance and return) as well as on-site on short notice if required
• Important: The activity must be carried out from Germany. Access from abroad is not permitted, and from EU countries only after prior approval.
• Environment: public contracting authority in the field of trust services and digital certificates
• Start: 2026-12
• Duration: 25 Monate
• Remote: remote
• Location: Berlin, Deutschland, DE
• Languages: German, English