Senior/Lead Full Stack Developer (Java/React) – Tieto Tech Consulting (m/f/d)

Location: Sofia, Sofia City Province, bg, Remote

Job Description

Tieto Tech Consulting (MentorMate from 2001 to 2026) is looking for a highly skilled and motivated Senior Java Full Stack Developer, a professional who will join a project within a Telecom Team for our respectful client BICS.

Join the software engineering team for our customer BICS – a global telecommunications enabler – and impact how billions of people communicate. 

Build solutions used by top enterprises and carriers: from network for voice, messaging, and data, to 5G IoT, roaming, signaling, and cloud communications businesses. Beyond traditional telecommunications, BICS is at the forefront of enabling digital transformation, cloud interconnectivity, IoT ecosystems, and next-generation mobile services, helping customers navigate the evolving global connectivity landscape. 

You won’t find micromanagement here, but you will find the support of a local People Manager, a diverse team, and an AI-enabled culture shaped to increase your productivity instead of replacing people. 

Become a part of the BICS community at Tieto Tech Consulting that has been growing since 2010 and enjoy the comfortable and stable environment where new ideas thrive. 

Responsibilities

• Design, develop, and maintain scalable applications using Java and modern frontend technologies
• Lead by example and mentor a development team in day-to-day delivery while continuously improving engineering practices
• Drive technical discussions and contribute to architecture decisions
• Collaborate closely with stakeholders, product owners, and cross-functional teams
• Ensure clean, maintainable, and well-tested code
• Take ownership of features and deliver end-to-end solutions independently

Requirements

• 5+ years of experience in commercial software development using Java
• Strong experience with Java 17+, Spring, Spring Boot, Hibernate, and JPA
• Good knowledge of JavaScript and React.js
• Experience in API design and development
• Strong understanding of relational and NoSQL databases, with expertise in writing and optimizing complex SQL queries
• Solid understanding of design patterns, clean code principles, and testing practices
• Experience working in Agile/Scrum environments
• Strong communication skills in English
• Openness to using modern AI tools in daily development workflows (e.g. GitHub Copilot, Claude Code, ChatGPT)
• Experience being involved in projects at their early stages, particularly in shaping solutions, collaborating with architects, and evaluating alternative approaches
• Comfortable taking ownership of technical decisions or defending a proposed solution when challenged
• Ability to travel abroad for business trips

Nice to Have

• Experience with microservices architecture
• Cloud and cloud-native experience (AWS is a plus; Azure or Google Cloud also valuable)
• Experience with OSS/BSS integrations; knowledge of CAMARA and GSMA standards is a strong advantage
• Experience with Test-Driven Development (TDD)
• Experience in performance tuning and system optimization

Personal Skills

• Leadership mindset with a hands-on approach
• Proactive, self-driven, and solution-oriented attitude
• Strong analytical and problem-solving skills
• Team player with a collaborative mindset
• Ability to estimate work accurately and commit to delivery plans

Additional Information

At Tieto, we believe in the power of diversity, equity, and inclusion. We encourage applicants of all backgrounds, genders (m/f/d), and walks of life to join our team, as we believe that this fosters an inspiring workplace and fuels innovation. Our commitment to openness, trust, and diversity is at the heart of our mission to create digital futures that benefit businesses, societies, and humanity.
Diversity, equity and inclusion | Sustainability | Tieto

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• For more information visit Important Advisory Regarding Recruitment Fraud | Tieto Blog