Senior Full-Stack Engineer @ Thessaloniki | Tax Technology Consulting

Are you looking for an opportunity in Thessaloniki that offers you a hybrid working model?

Are you ready to work on large scale projects for industry-leading clients around the world and elevate your career to an international level?

If so, check below for more info about this career opportunity!

You bring passion, we bring opportunities!

#YourOpportunity

At Deloitte, the spirit of excellence is part of our DNA. We strive to hire the brightest minds from all around the globe, allowing us to excel in both long-term strategic thinking and business improvement implementation as the undisputed global leader in professional services. We are committed to delivering impacting results for diverse private and public organization clients, linking our peerless talent in audit with unrivaled opportunities for impact – committing ourselves to sustainable growth and investment in our employees’ development and inclusion along the way.

Since 2018, Deloitte has been operating its Competence Center in Thessaloniki with satellites in the cities of Patras, Heraklion, and Ioannina - which are model hubs of expertise, training, and innovation, specializing in cutting-edge exponential technologies, in which graduates and young professionals undergo immersive experiences, continuous learning, gaining practical insights and hands-on training that empower them to navigate the complexities of the digital landscape.

Deloitte is an ideal working environment for both young and senior professionals who want to take the next step in their careers, offering them a supportive and international working environment that leverages their expertise and potential. Its corporate culture is based on trust and collaboration and ensures diversity and inclusion so that everyone feels part of a great team.

#YourServiceLine

Tax & Legal

As global forces fundamentally shift how the tax function operates, tax leaders must become strategic advisors. We collaborate closely with our clients, connecting them to expertise, capabilities, technology, and innovative ideas that enhance agility, enabling them to lead their businesses through complexity with confidence. KBVL, member of the Deloitte Legal international network, is an independent law firm registered with the Athens Bar, that offers legal services aligned with clients’ key business objectives.

#YourRole

As a Senior Consultant in our Tax Technology Consulting team, you will serve as a Senior Full Stack Engineer for our AI platform used across professional services.

The platform combines an Angular/TypeScript single page application with a Python backend, a multi-tenant architecture with role-based access control, real-time streaming, multiple data stores, and AI capabilities such as multi-model LLM support, agent workflows, and retrieval (RAG).

You will accelerate the delivery of new features and act as the technical glue between frontend, backend, and AI integrations. You will help evolve the architecture, set engineering standards, and mentor less experienced engineers through design discussions and code reviews.

You will work on a production AI platform used by professionals across multiple countries, alongside experienced engineers, with real influence on technical decisions and the product roadmap.

#KeyResponsibilities

• Design and deliver features end to end across the Angular frontend, Python/FastAPI backend, and data layer
• Coordinate technically across frontend, backend, and AI integrations, ensuring clean API contracts and consistent data flows
• Contribute to the evolution of the platform architecture, including agent orchestration, asynchronous and scheduled execution, and integrations with external tools and services
• Break down roadmap items into well-scoped technical tasks and help the team estimate and prioritise
• Conduct code reviews and mentor engineers, raising the bar on code quality, testing, and documentation
• Build and maintain real-time features such as streaming responses (SSE) and WebSocket notifications
• Work with the data layer across relational, document, and in-memory databases
• Apply security and access-control best practices in a multi-tenant environment
• Collaborate with QA and DevOps to keep CI/CD pipelines and releases reliable
• Work with product and business stakeholders to translate requirements into technical solutions

#RequiredSkills

To qualify for the role, you must have:

• Bachelor’s degree in Computer Science, Software Engineering, or a related field
• 3–6 years of professional full stack development experience, with demonstrated ownership of production features
• Strong proficiency in Python or TypeScript as your primary language, with a modern framework (FastAPI, Django, Flask, Angular, or React)
• Solid working knowledge of the other language and of both sides of the stack: Angular (React is transferable) on the frontend and an async Python backend
• Hands-on exposure to LLM integrations (model APIs, prompt engineering, RAG, or agents), through work, projects, or coursework, and strong interest in building AI products
• Solid understanding of REST API design, authentication and authorization (OAuth2, JWT), and relational and NoSQL databases
• Experience designing and evolving non-trivial software architectures
• Experience with Git workflows, code reviews, automated testing, and CI/CD
• Experience mentoring or technically guiding other engineers
• Excellent written and verbal communication skills in English

#PreferredSkills

• Production experience with LLM APIs (Azure OpenAI, OpenAI, or equivalent), agent frameworks, or RAG pipelines
• Experience with MongoDB, PostgreSQL, and Redis
• Experience with real-time patterns such as SSE and WebSockets
• Familiarity with Docker, Azure cloud services, and GitHub Actions or Azure DevOps Pipelines
• Experience with multi-tenant applications and role- or attribute-based access control
• Understanding of accessibility (WCAG) and internationalisation (i18n)
• Experience in a product-led or consulting environment

#WhatWeOffer

At Deloitte, we know that great people make a great organization. We value our people and offer employees a broad range of benefits.

• Modern hybrid workplace, characterized by flexibility and Smart Working
• Empowered well-being: We provide multiple program offerings to support your well-being needs (flexible working arrangements, extra days of leave, parental allowances)
• Engagement within international large-scale teams and projects, with opportunities to travel for training or client purposes.
• Constant opportunities for learning with unlimited access to internal and external learning platforms and sponsored certificates aligned with business needs and technology trends
• Challenging and innovating environment where personal development and growth are encouraged, always with transparency and trust
• Diverse culture and active communities that enable you to bring yourself to work
• Team Building and Corporate Social Responsibility Activities
• A buddy to support you with your onboarding
• Private medical health insurance plan
• Ticket restaurant card
• Exclusive Discounts to several retail providers, restaurants and others
• Mobile phone
• Fresh fruits and unlimited coffee everyday at our offices

Please note that all the well-being benefits mentioned above are subject to annual review.

About Deloitte

#OurServices

Deloitte offers integrated services that include Audit & Assurance, Tax and Legal, Strategy-Risk & Transactions Advisory, and Technology & Transformation. Our approach combines insight and innovation from multiple disciplines with global business and industry expertise to help our clients excel anywhere in the world. We deliver outstanding impact on the reputation and success of our clients, in Italy and globally. In pursuing this we contribute to a sustainable and prosperous society, and are firm believers in the positive impact business can and should have on the world it operates within.

#OurPurpose

We are led by a purpose, to make an impact that matters with clients, people and society. This purpose defines who we are and what we stand for. It's not about being the biggest. It’s about being the first choice for the largest and most influential clients, and the first choice for the best talent.

#OurValues

At Deloitte we foster a collaborative culture where talented individuals can produce their best work. We value innovative thinking, diverse insights and a genuinely distinctive level of customer service through our expertise and professionalism. We value difference, with respect at the heart of our inclusive culture.

#OurTalentExperience

From day one at our firm, practitioners are part of a community. Our development and career progression framework will help them develop the skills and capabilities to succeed. The wellness of our people and the ability to offer agile working arrangements is at the center of our unique talent experience. We create a workplace that encourages collaboration, creativity, inclusiveness to ensure our staff are supported, encouraged and feel a sense of purpose and meaning in what they do each day.

This document has been prepared by Deloitte Business Solutions Societe Anonyme of Business Consultants, Deloitte Certified Public Accountants Societe Anonyme and Deloitte Alexander Competence Center Single Member Societe Anonyme of Business Consultants.

Deloitte Business Solutions Societe Anonyme of Business Consultants, a Greek company, registered in Greece with registered number 000665201000 and its registered office at Marousi Attica, 3a Fragkokklisias & Granikou str., 151 25, Deloitte Certified Public Accountants Societe Anonyme, a Greek company, registered in Greece with registered number 0001223601000 and its registered office at Marousi, Attica, 3a Fragkokklisias & Granikou str., 151 25 and Deloitte Alexander Competence Center Single Member Societe Anonyme of Business Consultants, a Greek company, registered in Greece with registered number 144724504000 and its registered office at Thessaloniki, PAEGA Building, Land Port Zone of the Port of Thessaloniki, 54626 Thessaloniki, Greece, are all companies of the Deloitte Central Mediterranean S.r.l. (“DCM”) geography. DCM, a company limited by guarantee registered in Italy with registered number 09599600963 and its registered office at Via Santa Sofia no.28, 20122, Milan, Italy is one of the Deloitte NSE LLP geographies. Deloitte NSE LLP is a UK limited liability partnership and member firm of Deloitte Touche Tohmatsu Limited, a UK private company limited by guarantee.

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