Senior Full-Stack Software Engineer

Senior Full-Stack Software Engineer

Al & Product Engineering

Company: Avagance Limited (United Kingdom) Location: Hybrid / Onsite (Sri Lanka)
Employment: Full-time | Direct UK company hire Experience: 5+ years preferred

Salary: Rs. 250,000 - Rs. 300,000

About Avagance

Avagance is a UK-based technology company building an Al-native financial planning and wealth management platform. We're developing an intelligent platform that combines Al agents, financial planning and calculation engines, automated workflows, compliance systems, and web and mobile applications.

We're a small, ambitious engineering team working on complex technical challenges and building software designed to change how financial professionals work.

We're looking for an experienced Senior Full-Stack Software Engineer who can take ownership of engineering challenges across the entire product, from development and integration through to testing, deployment and ongoing improvements.

About the Role

This is a hands-on engineering role with broad technical responsibility. You'll work directly with our founding engineering team to build, maintain, test and continuously improve the Avagance platform.

We're looking for someone who doesn't see development, testing and deployment as separate jobs, but understands how they fit together to deliver reliable software. You'll contribute to product development, investigate complex issues, work across frontend and backend systems, implement integrations, and help ensure the application works seamlessly for real users.

We use Al development tools extensively, including Claude Code and OpenAl Codex, to accelerate software engineering, automate repetitive tasks and improve development efficiency. We expect you to use these tools effectively while maintaining strong engineering judgment and responsibility for the final result.

The role also involves a forward-deployed engineering approach: understanding real customer requirements, investigating problems in practical workflows and turning those findings into working product improvements.

Key Responsibilities

Full-Stack Product Development

• Design, develop and maintain features across frontend, backend and mobile applications.
• Work with APls, databases, integrations and distributed services.

Contribute to the development of Al-powered features and automated workflows.

Investigate and resolve complex engineering problems across the platform.

Improve application performance, reliability, maintainability and security.

Participate in architectural decisions, code reviews and technical planning.

Al Engineering & Agentic Development

Work with Al agents, LLM integrations, tool calling and multi-step workflows.

Develop and improve agent-powered application functionality.

Use Claude Code, OpenAl Codex and similar tools throughout the development lifecycle.

Build Al-assisted workflows for development, debugging, testing and automation.

Review and validate Al-generated implementations to ensure correctness and reliability.

Explore and implement new engineering approaches where they provide meaningful improvements.

Quality Engineering & Product Testing

Take an active role in ensuring the entire application works reliably from end to end.

Perform hands-on manual and exploratory testing to identify issues automated tests might miss.

Test complex user journeys across web, iOS, Android, backend services and integrations.

• Evaluate Al agent interactions, including voice conversations, text responses, tool usage and workflow execution.
• Use Al coding agents to develop and maintain automated regression tests.

Investigate, reproduce and resolve defects, then verify fixes.

Help maintain strong testing standards and release readiness across the platform.

Deployment, DevOps & Infrastructure

Work with GitHub Actions, Cl/CD pipelines, Docker and Linux environments.

Support application deployments, release validation and environment management.

• Investigate production and staging issues using logs, monitoring and debugging tools.
• Improve automation, build processes and engineering workflows.

Contribute to platform stability, performance and operational reliability.

Customer-Focused Engineering

Understand how advisers and clients use the application in real-world situations.

Translate customer feedback and technical requirements into practical solutions.

Investigate integration, configuration and workflow issues.

• Work closely with the founding team to identify opportunities for product improvements.
• Help deliver and validate solutions that address actual customer problems.

Technical Skills & Experience

Essential

5+ years of professional software engineering experience, or equivalent demonstrated capability.

Strong full-stack development skills using TypeScript, JavaScript, Python or similar languages.

Experience with modern frontend frameworks, backend development, APIs and databases.

Strong debugging, troubleshooting and problem-solving ability.

Experience working with Git, Cl/CD pipelines and modern development workflows.

Understanding of automated testing, integration testing and end-to-end quality assurance.

Ability to independently investigate problems across multiple parts of an application.

• Familiarity with Al-assisted software development tools, or demonstrable ability to adopt them effectively.
• Good communication skills and the ability to work independently in a distributed team.

Nice to Have

Experience developing Al-powered applications or multi-agent systems.

Familiarity with Claude Code, OpenAl Codex or similar agentic development tools.

Experience with React, Next.js, Node.js or Python-based backend systems.

« Experience with Playwright, Appium or similar testing frameworks.

Experience developing or testing native or cross-platform mobile applications.

Familiarity with voice Al, real-time communication or speech processing.

Knowledge of Docker, cloud infrastructure and self-hosted Cl systems.

• Experience working in fintech, financial services or regulated technology environments.
• Experience implementing customer-facing technical solutions or integrations.

What We're Looking For

We're looking for someone who takes ownership of problems from beginning to end. You should be equally comfortable developing a feature, investigating a failing API, exploring an unfamiliar part of the application, debugging an Al agent or tracking down a production issue.

We value engineers who are curious, practical and willing to challenge assumptions rather than simply accepting that something works because the tests pass.

You should enjoy working across different technical areas, learning new technologies and finding better ways to deliver reliable software. We don't expect you to know every technology in our stack. Strong engineering fundamentals, independent problem-solving ability and a willingness to learn are more important.

We're looking for an engineer who cares about the entire product, not just the code they write.

Why Join Avagance?

Work directly with the founders of a UK-based Al technology company.

Contribute to a complex, Al-native financial technology platform.

Take meaningful ownership across product development, Al engineering, testing and deployment.

Work extensively with modern Al-assisted development tools.

Solve challenging problems involving intelligent agents, financial systems, real-time interactions and distributed applications.

Be part of a small team where engineering decisions and contributions have a direct impact on the product.

How to Apply

Please send your CV, along with your GitHub profile or examples of previous engineering work where available, to with the email subject: Application — Senior Full-Stack Software Engineer — Al &
Product Engineering

We'd particularly like to hear about a complex engineering problem you've taken from investigation through implementation and deployment, and how you've used Al-assisted development tools in your workflow.

• Employment: Full Time, Permanent, Onsite
• Closing date: 24 Nov 2026
• Job ref: 1569561