Lead Java Developer/Architect

About the Company

OLSYS Ltd provides full-service solutions for mid-market and enterprise organizations.

As an enterprise software development company, we are building long term partnerships helping our clients accelerate their digital experiences with reasonable IT investments.

Our tailored approach, e-commerce focus, and flexible solutions allow us to design, develop, and deliver scalable, integrated commerce platforms that drive profits and boost the business.

15+ years of experience, 100+ projects, 200+ specialists.

About the opportunity

Our Client, a dynamic start-up company in the field of digital marketing, is seeking a talented Lead Java Developer/Architect to join their ambitious team. As the Lead Java Developer/Architect, you will have a unique opportunity to work closely with the highly experienced Chief Technology Officer (CTO) who has a proven track record in successfully creating tech start-ups. This collaborative environment will provide you with the chance to contribute directly to the project from its inception.

This is a challenging and rewarding opportunity for a mature, experienced, and self-driven Lead Java Developer/Architect to make a significant impact on a start-up project in digital marketing. If you are passionate about cutting-edge technologies, AI integration, and being part of a highly collaborative team, we would love to hear from you.

Requirements:

• 10+ years of commercial hands-on development experience using Java-related technologies.
• 3-5+ years of technical and team management experience.
• Proven experience in building large-scale, complex applications.
• Extensive knowledge of Java frameworks and libraries (e.g., Spring, Hibernate).
• Proficiency in object-oriented design principles, design patterns, and software architecture.
• Experience with relational databases (e.g., PostgreSQL, MySQL, Oracle) and proficiency in SQL.
• Hands-on experience with AWS services including EC2, Cognito, IAM, Secrets Manager, RDS, Route 53, Lambda (minimal), CloudWatch, and CloudFront.
• Familiarity with XSL and XSLT.
• Experience with integrating LLMs (Large Language Models) through prepared API prompts.
• Ability to work in a fast-paced start-up environment, adapt to changing priorities, and meet tight deadlines.
• Self-driven and proactive mindset, with the ability to take ownership of projects and drive them to completion.
• Strong problem-solving and analytical skills, with the ability to troubleshoot complex technical issues.
• Excellent communication and collaboration skills, with the ability to work effectively in cross-functional teams.

Would be a plus:

• Experience of work in Product companies.

English: Upper intermediate

Responsibilities:

• Lead the development of a cutting-edge project in digital marketing — delegating tasks, managing workload distribution, and ensuring timely, high-quality delivery.
• Design and develop backend architecture using Java 17, Spring, and PostgreSQL.
• Collaborate closely with the CTO to define the technical roadmap, architecture, and product vision.
• Mentor and guide a team of Java engineers, ensuring the delivery of high-quality software.
• Manage and optimize AWS infrastructure components.
• Integrate with popular AI engines such as GPT-5, Bard, and others to leverage advanced capabilities.
• Implement interaction with LLMs through prepared prompt APIs.
• Write high-quality, scalable, and maintainable code in Java.
• Help develop product hypotheses and contribute to the creation of proof-of-concepts (POCs).
• Drive innovation and bring creativity to the project, offering new ideas and solutions.
• Collaborate with cross-functional teams including product managers, designers, and data scientists to ensure seamless project execution.