Are you passionate about working with the most cutting-edge technologies, including AI, big data analytics, LLMs, data mining, and business intelligence (BI)? Are you looking to become part of a world-class engineering team? Do you aspire to contribute to a globally recognized, pre-IPO leader in technology?

As a Senior Software Engineer, you will contribute to the design and development of AI-driven architectures that power our next-generation intelligent customer engagement platforms. Your contributions will help shape AI-powered customer experiences, enhancing the intelligence and efficiency of our service platforms.

Job Responsibilities:

• Develop and enhance a cloud-based data foundation system and AI agent platform. This involves leveraging AI/ML models, applying prompt engineering techniques, and conducting data analysis across structured, semi-structured, and unstructured data. Utilize technologies such as data and pattern mining, business intelligence (BI), and data transformation and processing.
• Collaborate with cross-functional teams, including data scientists, software engineers, product managers, and business stakeholders, to deliver a high-performance, reliable, scalable service with assured AI quality.
• Contribute to architectural discussions, providing technical design input and ensuring alignment with the overall technology roadmap while adopting best practices effectively and independently.
• Participate in shaping the engineering roadmap, ensuring solutions are scalable and extensible while meeting business needs.
• Support and mentor junior engineers, fostering a collaborative and innovative development culture.
• Stay up-to-date with industry trends, emerging technologies, and advancements in AI and data engineering.

Qualifications:

• Bachelor's or Master's degree in Computer Science, Engineering, or a related field.
• 5+ years of experience in backend development for cloud-based services, with a strong focus on scalability, reliability, and performance.
• Proficiency in Java, Python, C++, C#, Kotlin, Scala, or similar languages.
• Experience building and optimizing data-intensive services, including data processing, transformation, storage, and retrieval at scale.
• Strong problem-solving skills and ability to design scalable solutions for AI-driven services.
• Strong written and verbal English communication skills.
• Prior experience with data platforms and/or AI services is highly desirable.
• Experience working with distributed data platforms and modern data architectures, such as Apache Spark, Databricks, Kafka, Delta Lake, or similar is a desirable.
• Experience in data science and practical experience applying AI/ML models is a plus.

Additional Notes:
This position will follow a hybrid work model.

Location: Portugal

Department: Engineering

Employment: Full time

About YLD:

Everything we do is to empower our clients to move forward. Our purpose is to help our clients develop the capabilities they need to outperform their competitors. Our success is a consequence of ensuring our clients are successful. Our company is built on extraordinary people; we aim to attract, inspire, develop and retain them. YLD is a software engineering and design consultancy; we create digital capabilities for our clients that last beyond our engagement. We have offices in London, Lisbon, Porto.

About the role:

As a Software Engineer, you’ll be part of a client team building innovative products. We expect you to be curious, passionate, driven, and enthusiastic. You’ll be proficient at problem-solving, and crafting scalable, resilient, and fault-tolerant architectures. You’ll be an effective communicator and a team player. You and your team will move in a fast-paced engineering environment, achieving outstanding results and delivering exciting projects.

About you:

A YLD Software Engineering Consultant is a highly skilled developer who exemplifies the highest standard in software engineering and enjoys sharing their knowledge and experience with others.

You’ll have the opportunity to build and deliver software within some interesting projects in terms of the product and methodology. We work in an Agile environment (Scrum) with a test-first mindset (actually, writing code without tests should be unthinkable). We are also big advocates of pair programming and nothing is released until we have a code review.

You have a real passion for problem-solving and are an active learner who gets excited by working collaboratively with those around you.

Your day-to-day responsibilities will look like this:

• Crafting excellent products! As an AI Engineer, you will be building new AI-powered features that meet the needs of our clients' customers, as well as improving their Digital Platform with intelligent capabilities;
• Continuously delivering changes to products including AI model integrations, prompt optimisations, and system improvements, as we push for a full CI/CD model;
• Working closely with your team, regularly collaborating on both traditional engineering and AI initiatives, to continually push yourselves to build better, smarter systems;
• Participating in regular show and tells to promote your work — from AI experiments to production deployments — to both your department and the wider company;
• Joining our clients’ internal events, including meeting external speakers, going to quiz nights, etc.

You’ll have the following skills and experience:

Core Programming & AI

• Proven strong experience with JavaScript, TypeScript, and Python
• Advanced GenAI/LLM expertise: RAG, embeddings, vector search, prompt engineering, evals, guardrails, caching, chaining, function calling, etc
• Fine-tuning expertise: LoRA/QLoRA, instruction tuning, RLHF, domain adaptation, and custom model training
• Agentic architecture design: multi-agent systems, tool orchestration, planning/reasoning frameworks, memory systems, and agent coordination patterns
• Eval systems: automated evals, human feedback loops, benchmarking, A/B testing, safety testing, hallucination detection, and performance metrics
• Experience with LLM frameworks (LangChain, LlamaIndex, LiteLLM, CrewAI, Mastra, etc) and API integrations (OpenAI, Anthropic, etc.)

Infrastructure & DevOps

• CI/CD pipelines and IaC tools (Terraform, CloudFormation, CDK)
• Cloud platforms (AWS, Azure, GCP) for GenAI workloads and API management
• Containerisation and orchestration (Docker, Kubernetes) for AI applications
• LLM hosting and inference optimisation (vLLM, TGI, local deployment)

Data & Databases

• Vector databases (Pinecone, Weaviate, Chroma, Qdrant) and traditional databases (PostgreSQL, Neo4j)
• Data pipeline design for RAG and knowledge ingestion
• Real-time data streaming and processing
• Document processing and embedding generation workflows

Frontend & APIs

• React or modern UI frameworks
• API design for LLM services and conversational interfaces
• Multiple protocols (HTTP, GraphQL, gRPC, WebSockets, MCP)
• Real-time chat and streaming response handling

Performance & Reliability

• Building high-performance, scalable AI applications
• LLM cost optimisation, token management, and caching strategies
• Performance monitoring, observability, and debugging production AI systems
• Comprehensive testing: unit, integration, AI behaviour, security, accessibility

You’ll be:

• Self-motivated, proactive and always looking for ways to improve and develop yourself;
• A good communicator, both in writing and verbally. You’ll be able to explain technical ideas and concepts in business-friendly language;
• Detail oriented;
• Used to working in a team-oriented, collaborative environment;
• Comfortable with experimentation, iteration, and managing uncertainty in AI systems;
• Analytical and problem-solving oriented;
• Ethical thinker who considers the broader implications of AI implementations;
• A genuine believer in diversity and fairness.

As well as the chance to work with a forward-thinking, ethical, and fun group of people, you’ll also get:

• Company Private Health care
• Enhanced fully paid maternity and paternity leave for up to 6 months
• 25 days annual holiday (excluding Public Holidays)
• €2000 annual allowance for Training/Conferences
• €300 annual allowance for additional hardware
• Wellbeing & Performance Support via Oli including Therapy and Coaching
• Discretionary Bonus (depending on Company performance and results)
• Company laptop
• Generous referral schemes

Our typical Recruitment Process looks like this:

• 1st Interview with someone from the Talent team (30/45 mins)
• Technical Interview with our Senior Developers (1h30)

We live and breathe our values, and know you will too:

• Growing every day
• Including everyone
• Relationships built on honesty and ethics
• Inspiring solutions
• Winning together

We’re an equal-opportunity employer and value diversity of all kinds. We don’t discriminate based on race, religion, colour, national origin, gender, sexual orientation, pregnancy or maternity, age, marital status, or disability status. We also offer a remote-first working environment, meaning that flexible working and work-life balance come as standard for all employees.