Senior Full Stack Software Engineer - Series A FinTech

This role is offered by Bondaval. Your actual pay will be based on your skills and experience – talk with your recruiter to learn more.

We are looking for multiple mid‑senior‑lead Full Stack / Back End Engineers to join our high‑calibre engineering team. You will design, build, and maintain the core services and APIs that power our proprietary platform, with opportunities to contribute to both back‑end and front‑end codebases, and explore AI & LLM agents and frameworks. You will work closely with the CTO, product, and data teams to deliver robust, scalable solutions.

Location: London (Hybrid – 5‑minute walk from London Bridge Station)

About BondAval: Founded in 2020, BondAval is a fast‑growing fintech transforming B2B credit with innovative, technology‑enabled solutions, serving global blue‑chip clients across the UK, Europe, US, and Canada. Having secured Series A funding and with Series B in the pipeline, Bondaval is backed by top European and American VCs such as Octopus Ventures, Tallis Capital, Expa and Dawn Capital, alongside Angel Investors like Tom Blomfield (founder of Monzo) and Carlos Cadenas (Index Ventures, GoCardless, Skyscanner).

The Role: As a Technical Lead, you will report to our CTO and help drive the next evolution of our platform, designing architecture, managing engineers and shaping how we integrate AI and large language models into our products and workflows. You will design, implement, and maintain scalable back‑end services and APIs (primarily in Go, with Python for scripting and data). You lead by example, build fast and help shape our technical roadmap. As a mid‑senior software engineer, you will take full lifecycle ownership of end‑to‑end delivery — from technical design and implementation through to testing, deployment, and monitoring. Contribute to front‑end code (VueJS) as needed, supporting a collaborative, full‑stack environment. Work with relational databases (Postgres) and NoSQL solutions (MongoDB, Redis). Participate in architectural discussions and technology decision‑making. Help improve CI/CD pipelines and infrastructure (AWS, Ansible, GitHub Actions). Write clean, maintainable, and well‑tested code. Mentor team members and share knowledge across disciplines. Contribute to open‑source libraries and research where relevant. Demonstrate a strong understanding of BondAval’s ethos and values in your work. Actively seek to understand the business, product, and our customers’ needs. Embrace and implement AI tools and workflows, using AI to enhance your productivity and the quality of your work.

What We’re Looking For:

• 3‑6+ years of software engineering experience (dependant on the role).
• Strong proficiency in a back‑end server‑side language (Go preferred, Python or Java applicable).
• As a senior/lead, you will have built and designed distributed systems and scalable architectures.
• Experience with relational databases (Postgres) and NoSQL databases (MongoDB, Redis, Cassandra).
• Experience with RESTful API design and integration.
• Familiarity with front‑end frameworks (VueJS, React, or Angular).
• Good knowledge of source control (Git) and CI/CD tools.
• Understanding of infrastructure and deployment (AWS, Ansible, Kubernetes).
• Architectural skills and experience with microservices.
• A genuine interest in AI and LLMs — from using tools like Cursor and Copilot to experimenting with frameworks such as Hugging Face or LangChain is highly desirable.
• AI literacy and an interest in using AI tools to improve workflow and product outcomes.
• Degree in Computer Science (or similar) from a good University highly desirable.

Nice to Have:

• Familiarity with message brokers (Kafka, SQS/SNS, RabbitMQ).
• Knowledge of real‑time streaming (Kafka Streams, Apache Flink, etc.).
• Exposure to big‑data or machine‑learning frameworks (TensorFlow, PyTorch, Hugging Face, LangChain).
• Understanding of infrastructure and DevOps (Terraform, Ansible, AWS, Kubernetes).
• Exposure to fintech or start‑up environments.

Mindset & Attributes:

• Positive, objective‑focused, and collaborative.
• Willingness to teach and learn from others.
• Strong communication and teamwork skills.
• Passion for software security and quality.
• Eager to understand the business domain and BondAval’s product.
• Demonstrates BondAval’s values in daily work.
• Embraces the rise of AI and seeks to use it to their advantage.

Why Join Us?

• Employee share options – earn a stake in the company you’re helping to build!
• Hybrid working environment with a vibrant office culture on Bermondsey Street.
• Generous benefits package: private healthcare, private pension plan, bike‑to‑work scheme, £100/year towards a physical challenge of your choice, and more!

Seniority level: Mid‑Senior level

Employment type: Full‑time

Job function: Information Technology