Mid-Level Engineer

Location: Cardiff

Hybrid Working

Salary: up to £55,000 depending on experience, plus a potential bonus up to £11,000

A hands-on role building features from design through to production and helping junior engineers improve, at one of Europe's leading financial businesses

The Role

You'll join the Engineering team at LDMS as a Mid-Level Engineer, working within a single team and reporting to an Engineering Team Lead. You'll design and build features end-to-end, from working out the approach to getting them into production and checking they work once they're live. You'll work within the technical direction and patterns set by your Lead Engineer and the senior engineers on your team. Our stack is React and TypeScript on the frontend, Java with Spring Boot on the backend, and PostgreSQL with schema-per-tenant multi-tenancy underneath, all cloud-hosted on AWS.

You'll be responsible for the quality of your own work, review other people's code, take part in design discussions, and help newer engineers when they get stuck. Over time you'll take on bigger pieces of work that cover several parts of the system, and decide how the features you own are tested. This is a hands-on role, not a line-management one.

Key Responsibilities

These may change with the needs of the business, but the main areas are:

Technical Skills

• Design and build small to medium features end-to-end without needing close supervision, keeping the code easy to maintain.
• Make good technical choices within our existing patterns and be able to explain why you made them.
• Write unit, integration and contract tests, and decide how the features you own should be tested, including failure cases.
• Think about performance and security when you design a feature, so problems are caught early.
• Spot technical debt, raise it and help fix it.

Delivery

• Plan and deliver features end-to-end, managing your own time and raising risks early.
• Work out dependencies and unknowns at the start and deal with them before they hold things up.
• Check your work in production and watch for regressions after release.
• Keep work moving when things are unclear, and ask the questions you need to get answers.
• Give estimates you can stick to, and update them when the scope changes.

Impact

• Be someone your team relies on to get work done.
• Help junior engineers with technical questions, pair with them and give them feedback.
• Take part in hiring by running technical interviews and giving clear feedback on candidates.
• Suggest ways the team could work better, and see the change through if you're asked to lead it.
• Take part in team planning and help decide what goes into the backlog.

Communication

• Explain things in a way that suits who you're talking to, with more detail for engineers and less for everyone else.
• Speak up in design reviews, retros and sprint planning.
• Give clear, specific and kind feedback in code reviews.
• If you disagree with something, say so early and professionally.
• Let your Engineering Team Lead know early when a piece of work is falling behind, rather than letting it surface late.

AI and Innovation

• Use AI coding tools such as Claude in your day-to-day work, while you stay in charge of the design decisions.
• Review AI-written code to the same standard as your own, and check that generated tests actually test the requirement.
• Follow the team's agreed approach to using AI, and update the guidance for your area when your changes make it out of date.

Requirements

Essential

• Solid, hands-on experience in Java (preferably Java 25+) and Spring Boot.
• Good relational database skills, ideally PostgreSQL, including working with schemas and migrations.
• Experience designing and delivering features from planning through to production.
• Experience writing unit, integration and contract tests.
• Comfortable working within an existing architecture and set of patterns.
• A good understanding of secure coding and how to write code that performs well.
• Experience working with CI/CD pipelines (for example Jenkins).
• Able to explain technical work clearly to engineers and non-technical colleagues.
• Comfortable getting on with work when the requirements are not fully clear.

Desirable

• Experience using AI coding tools such as Claude well as part of day-to-day engineering.
• An understanding of what it takes to build software in a financial environment.
• Some experience monitoring and debugging services (for example Prometheus, Grafana).
• Experience working with cloud-hosted systems on AWS.
• Exposure to React and TypeScript, enough to work sensibly with patterns defined.
• Familiarity with tools such as Keycloak for identity and AWS S3 for storage.
• Experience helping more junior engineers or taking part in technical interviews.