29 jobs found

A high-growth, award-winning specialist lender is seeking a Junior Software Developer to help build and implement a highly automated, bespoke lending platform. Having featured on the Financial Times 1000 fastest-growing companies in Europe for two consecutive years, this firm is now looking to transform its operating efficiency and scalability through in-house technology. Location : London Hybrid : 4 days on-site, 1 day remote Salary : £40,000 to £45,0000 This is a frontend-focused role with some backend requirements. You will join a small, agile team and work directly with the company s co-founders, playing a fundamental role in the evolution of their technology stack. Responsibilities Build and maintain modern web applications using React and Next.js . Develop clean, intuitive user interfaces with a strong focus on UI design and usability. Integrate frontend components with RESTful APIs and backend services. Work with Node.js and related development tools to support the full application lifecycle. Collaborate on CI/CD pipelines and ensure high-quality code through testing and TDD practices. Assist in the transition towards highly automated, data-driven lending processes. Requirements Proficiency in TypeScript and JavaScript . Strong experience with React and Next.js. Experience using Node.js. Proven ability in UI development and CSS styling libraries. Working knowledge of RESTful APIs and frontend-backend integration. Exposure to cloud platforms (Azure, AWS, or GCP). Understanding of CI/CD pipelines and testing practices (TDD). Desirable Skills Python and FastAPI for backend development. Experience with AI-assisted development tools and AI agents. Awareness of Model Context Protocol. Experience working with Figma or collaborating from design files. This role is ideal for a motivated and disciplined developer, whether self-taught, formally educated, or professionally experienced, who wants to see their code have a direct impact on a company s growth and operational success. Ripple Recruitment is acting as an employment agency for this vacancy. My client is an equal opportunity employer committed to fostering a diverse and inclusive workplace. Due to high volumes of interest, we can only respond to shortlisted applicants.

We are looking for a skilled Java Full Stack Developer with expertise in modern web technologies, cloud infrastructure, and emerging Generative AI capabilities. The ideal candidate will be responsible for designing, developing, and deploying scalable applications using Java-based microservices and React-based frontends, while leveraging cloud-native and DevOps practices. Java Full Stack with React and Gen AI, Docker/Kubernetes, Terraform/Cloud Formatoin, MQ/Apache Kafka, Datadog/AppDynamics/Dynatrace. Required Skills Backend: Strong experience in Java , Spring Boot, and Microservices Knowledge of REST APIs, security (JWT, OAuth), and database design Frontend: Proficiency in React.js , JavaScript (ES6+), HTML, CSS Experience with state management (Redux or similar) Cloud & DevOps: Experience with Docker and Kubernetes Hands-on with Terraform or CloudFormation Familiarity with AWS or other cloud platforms Gen AI Messaging: Experience with Apache Kafka or other messaging systems Hybrid: 2/3 days in a week Onsite.

Cloud Software Architect Java - BackEnd, Back End Google Cloud (GCP) Contract: Until December 2026 - Renewable Location: Essex Offices (located between Brentwood and Basildon) 4 days a week Rate: £600 per Day Inside IR35 The finance and banking division of this engineering company and household name is seeking a Software Engineer, Software Developer Software Architect to be responsible for designing, developing, testing and maintaining software applications and products to meet customer needs. The Software Architect will be involved in the entire software development lifecycle including designing software architecture, writing code, testing for quality. They are particularly interested in Version control systems (e.g. Git/GitHub) and CI/CD tools (e.g. Cloudbuild), including defining and optimising pipelines for backend deployments Main Tasks and Responsibilities Software Architect SDLC - BackEnd, Back End Google Cloud (GCP) Essential Skills & Experience Software Architect SDLC - BackEnd, Back End Google Cloud (GCP) # Java # Spring Boot # JUnit # GCP (Google Cloud Platform) # GitHub # Jetbrains products (e.g., IntelliJ IDEA) # Fossa (or similar open-source licence compliance tools) # SonarQube (or similar code quality analysis tools) # Checkmarx (or similar static application security testing tools) # Cycode (or similar software supply chain security platforms)

About Synechron: Synechron is a leading digital transformation consulting firm dedicated to delivering innovative technology solutions within banking, financial services, and insurance. We thrive on engineering excellence, collaboration, and a passion for cutting-edge technologies. We are seeking a highly experienced Lead Full Stack Java Developer (10+ years) with strong expertise in the latest Core Java versions to lead and drive end-to-end development activities. The role requires a hands-on technical leader capable of guiding a development team, providing architectural and coding solutions, and ensuring successful delivery of high-quality applications Key Responsibilities Lead and manage a team of full stack developers , providing technical direction, guidance, and mentorship. Drive the design, development, and implementation of scalable, high-performance applications using modern Java. Take ownership of development activities, ensuring alignment with delivery timelines, quality standards, and best practices. Act as a solution provider , assisting the team in resolving complex technical challenges. Participate in architecture and design discussions, ensuring robust and maintainable solutions. Review code and designs to ensure compliance with coding standards and performance benchmarks. Collaborate closely with business stakeholders, architects, and QA teams to translate requirements into technical solutions. Support troubleshooting, debugging, and resolution of production issues. Promote best practices in code quality, performance, security, and maintainability. Technical Skills Required Strong hands-on experience with latest Core Java (Java 17/21/24) Full Stack development experience: Backend: Java, Spring/Spring Boot, REST APIs Frontend: Angular/React/other modern UI frameworks Solid understanding of object-oriented design, design patterns, and clean code principles Experience with SQL and relational databases Familiarity with build tools, version control, and CI/CD pipelines Diversity Statement Synechron are proud to be an equal opportunity employer. Our Diversity, Equity, and Inclusion (DEI) initiative Same Difference' is committed to fostering an inclusive culture - promoting equality, diversity and an environment that is respectful to all. We encourage applicants from across diverse backgrounds, race, ethnicities, religion, age, marital status, gender, sexual orientations, or disabilities to apply. We offer flexible workplace arrangements, mentoring, internal mobility, learning and development programmes to support our global workforce. Empowerment and collaboration are at the core of how we operate. All employment decisions at Synechron are based on business needs, job requirements and individual qualifications, without regard to the applicant's gender, gender identity, sexual orientation, race, ethnicity, disabled or veteran status, or any other characteristic protected by law.

Software Engineer, Developer - Frontend - React, JavaScript Contract - Until 31 December - Renewable Rate: £600 per Day - Inside IR35 Location: Essex Offices (between Brentwood and Basildon) 4 days a Week The banking and finance division of one of the world's leading engineering and manufacturing companies and a household name is seeking a Software Developer, Software Engineer - Front End, Frontend. The Frontend software developer will be working within a single team assisting with the creation of new frontend products for customers. It is expected the Software Engineer will upskill other team members with the knowledge required around creating leading frontend applications. Essential Skills & Experience Software Engineer, Developer - Frontend - React, JavaScript Desirable (not essential) Skills & Experience Software Engineer, Developer - Frontend - React, JavaScript # Software engineering (Backend) # Networking (Subnets, Firewall, Load balancing, VPN configurations) # Security and identity management # Monitoring and logging # Problem-Solving and debugging

Java Developer - SC Cleared - Spring Boot / AWS - Croydon (Hybrid) Location: Croydon (Hybrid Working) Clearance: Active SC Clearance required Type: Contract Rate: 475 per day Duration: 12 months Overview We are looking for an SC Cleared Java Developer to support the delivery of modern, cloud-based applications within an AWS environment. The role will involve backend development, API delivery, and contributing to greenfield microservices-based solutions. Hybrid working is required, with on-site presence in Croydon . Key Skills (Essential) Strong Java development experience Spring Boot SQL and report writing Experience working in AWS environments EBSA experience API development and microservices architecture Experience with CI/CD pipelines Containerisation using Docker and/or Kubernetes Experience delivering greenfield development projects Active SC Clearance Desirable Skills React Next.js Experience working within Agile delivery teams Responsibilities Develop backend services using Java and Spring Boot Build and maintain REST APIs Work with AWS cloud infrastructure Contribute to microservices and containerised deployments Support delivery of new system builds (greenfield) Collaborate with cross-functional teams in an Agile environment

Contract Java Developer - Enhanced DV Cleared New Contract Opportunity for a Java Software Developer in Cheltenham with eDV Clearance New contract opportunity working on highly secure operational systems within the National Security domain Enhanced DV (eDV) Clearance required for access to high-side systems Cheltenham based - 3 days per week on-site 24 month contract Daily rate up to £700 DOE To apply please email or call WHO WE ARE? We are recruiting for a highly secure government programme delivering critical capabilities across the UK National Security sector. Working within a collaborative and fast-paced engineering environment, you will contribute to the development of secure, scalable software solutions used to support real-world operational outcomes. Due to the sensitive nature of the work, candidates must hold active Enhanced DV (eDV) clearance . WHAT WILL THE JAVA DEVELOPER BE DOING? You will be joining an experienced engineering team developing and enhancing secure backend systems that underpin mission-critical capabilities. The role involves designing, developing and maintaining Java-based services within highly secure environments, collaborating closely with other engineers, architects and stakeholders to deliver robust and reliable software. WE NEED THE JAVA DEVELOPER TO HAVE Active Enhanced DV (eDV) Clearance Strong Java development experience Experience working within secure or government environments Experience with microservices architectures Knowledge of RESTful APIs and backend services Experience working in Agile delivery teams IT WOULD BE NICE FOR THE JAVA DEVELOPER TO HAVE Experience with Spring / Spring Boot Exposure to containerisation (Docker / Kubernetes) Experience with CI/CD pipelines Knowledge of cloud environments such as AWS or Azure TO BE CONSIDERED Please either apply by clicking online or emailing me directly to . For further information please call me on . I can make myself available outside of normal working hours to suit you.

MCS Group is delighted to be working with a global financial technology organisation as they expand their engineering team in Belfast with the addition of a Full-Stack Java Engineer This is an opportunity to join a highly regarded technology function within a large, established financial services environment, building robust, high-performance systems used by clients across international markets. The team operates in an agile, delivery-focused way and values engineers who enjoy solving complex problems and building software that truly matters.The RoleYou'll join a collaborative development team responsible for designing and building internal tools and client-facing services that support a fast-moving, data-driven trading environment. The role offers genuine ownership across the full development lifecycle, from design through to production support, while working closely with product, trading and support stakeholders.What You'll Be DoingDesigning and developing scalable Java-based services using modern frameworksBuilding and enhancing web applications using Angular and TypeScriptWorking across the full SDLC, including design, development, testing and optimisationCollaborating closely with product and business stakeholders to deliver high-quality solutionsContributing to agile delivery, technical discussions and continuous improvementSupporting production systems and helping resolve complex technical issues when requiredWhat We're Looking ForStrong commercial experience with Java and modern backend frameworks (e.g. Spring)Front-end experience with Angular and TypeScriptSolid understanding of RESTful APIs, web technologies and relational databasesExperience working in a performance-critical or complex systems environmentStrong problem-solving skills and the ability to work effectively in a teamA background in Computer Science, Engineering, Mathematics or equivalent experienceWhy Apply?Work on high-impact, business-critical systemsJoin a well-established engineering team with a strong delivery cultureHybrid working model based Long-term career progression within a stable, global organisation To speak in absolute confidence about this opportunity, please send an up to date CV via the link provided or contact matthew rainey at Even if this position is not right for you, we may have others that are. Please visit MCS Group to view a wide selection of our current and exclusive roles MCS Group is committed to Equality, Diversity, and Inclusion for all, being the first recruitment agency in NI to achieve Bronze Diversity Mark accreditation, if you have a disability which means you require a reasonable adjustment to be considered at any stage of the recruitment process, please contact us and we will endeavour to facilitate the request. Not all agencies are the same MCS Group are passionate about providing a first-class service to all our customers and have an independent review rating of 4.9 stars on Google.

Node Developer - Remote Working Lynx are currently working with a large IT consultancy to help them source a Node Developer. Our client is large global Consultancy who work with enterprise clients, solving their business and technology problems using cutting edge Solutions. Responsibilities: Design, implement, and manage backend applications and APIs using Node.js Work with RESTful APIs and external services to enhance system capabilities and connectivity Perform unit and integration testing, troubleshoot issues, and maintain high code reliability Collaborating with stakeholders and leadership to understand and refine project requirements Working on diverse projects and challenges in a consultancy capacity Advocating for and contributing to best practices in software engineering across teams and projects Key skills and experience: Previous experience working within a consulting organisation is essential Must be either SC cleared or eligible Experience working as a Software Engineer Strong Node.JS development experience Strong knowledge of JavaScript Experience working within cloud environments If this role sounds of interest, then please apply with your updated CV.

Cloud Application Developer £50,000-£65,000 + £15,000 (once clearance in place) eDV role - not required to start Manchester or Cheltenham (remote, then on site once cleared) Sanderson Government and Defence are supporting a commercial supplier to government in their search for a Cloud Application Developer to work out of either Manchester or Cheltenham. This client, aside from offering a very strong package, offer an excellent development programme, with a real willingness to support both financially and otherwise. Tech wise, we have requirement for both Java and Python backend languages, and cloud experience would also be very helpful indeed. AWS is by far the most prevalent, but we will look at individuals with transferable experience in this area. We need individuals who are eligible for a high level of security clearance, which will be explained in further detail in the initial screening call. Reasonable Adjustments: Respect and equality are core values to us. We are proud of the diverse and inclusive community we have built, and we welcome applications from people of all backgrounds and perspectives. Our success is driven by our people, united by the spirit of partnership to deliver the best resourcing solutions for our clients. If you need any help or adjustments during the recruitment process for any reason , please let us know when you apply or talk to the recruiters directly so we can support you.

Senior Backend Engineer (Golang) Onsite: Tuesday, Wednesday, Thursday Our client is looking for an experienced Senior Backend Engineer with strong Golang expertise to help shape the systems, processes, and architecture driving their mission. If you re a hands-on problem solver who thrives in fast-paced, collaborative environments, this is a chance to work on impactful projects while accelerating your career in a growing company. The Role You ll be part of a cross-functional squad, delivering new features and capabilities that the business depends on. The backend is built in Go, following a documentation-first approach and a service-oriented architecture. High code quality, automated testing, and seamless deployments through CI/CD pipelines into AWS are core to the way they work. What You ll Be Doing Build & Deliver Write clean, testable, maintainable Go code Break down User Stories into clear, deliverable tasks Drive best practices across testing, code reviews, and refactoring Ensure compliance with coding standards, security, and regulations Collaborate & Influence Partner with product owners, designers, and engineers to turn requirements into technical solutions Contribute ideas that improve systems and processes Shape the Future Support technical roadmaps and long-term strategies Stay ahead of industry trends, sharing insights that spark innovation About You You enjoy tackling complex challenges, simplifying problems, and delivering outcomes that matter. You re action-oriented, detail-focused, and thrive in a collaborative, team-driven environment. Clear communication and a positive, empathetic approach set you apart. What You ll Bring 5+ years of software development with strongly typed languages (Go, Java, etc.), including 2+ years of commercial Golang experience Strong experience writing well-tested code Proven ability to take a User Story from refinement through to delivery within a sprint Solid background in data modelling and database design (SQL/NoSQL) Knowledge of distributed systems and event-driven architectures Experience building cloud-based REST API solutions Excellent communication and collaboration skills Nice to Have SaaS product experience Expertise in microservices and event-driven integration Knowledge of AWS architecture Familiarity with Terraform or other IaC tools Degree in Computer Science, Engineering, or related field

Cloud Application Developer £50,000-£65,000 + £15,000 (once clearance in place) eDV role - not required to start London, Manchester or Cheltenham Sanderson Government and Defence are supporting a commercial supplier to government in their search for a Cloud Application Developer to work out of either Manchester or Cheltenham. This client, aside from offering a very strong package, offer an excellent development programme, with a real willingness to support both financially and otherwise. Tech wise, we have requirement for both Java and Python backend languages, and cloud experience would also be very helpful indeed. AWS is by far the most prevalent, but we will look at individuals with transferable experience in this area. We need individuals who are eligible for a high level of security clearance, which will be explained in further detail in the initial screening call. Reasonable Adjustments: Respect and equality are core values to us. We are proud of the diverse and inclusive community we have built, and we welcome applications from people of all backgrounds and perspectives. Our success is driven by our people, united by the spirit of partnership to deliver the best resourcing solutions for our clients. If you need any help or adjustments during the recruitment process for any reason , please let us know when you apply or talk to the recruiters directly so we can support you.

Role: Backend Developer Contract: 6 months Location: Canary Wharf, London Working model: Hybrid - 3 days onsite We're looking for a talented Backend developer with strong Java and Node.js/TypeScript experience to join a dynamic development team within a leading financial services organisation. This role is ideal for someone who enjoys working across both backend development and infrastructure, collaborating with centralised DevOps teams, and contributing to modern, large-scale financial services platforms. What You'll Do Maintain and enhance scalable back-end applications using Java, Node.js, and TypeScript. Lead the migration of existing Node.js systems into Java to align with bank-wide infrastructure strategy. Work closely with DevOps teams, utilising Docker and Kubernetes for containerisation and deployments. Build and maintain CI/CD pipelines (GitHub Actions). Monitor and optimise system performance and uptime. Write robust unit and integration tests to ensure high code quality. Collaborate with cross-functional teams to define, design, and deliver new features. What We're Looking For 5+ years' experience as a Java & Node.js/TypeScript developer. Hands-on experience with Docker, Kubernetes, GitHub Actions (CI/CD). Strong knowledge of SQL databases. Proven track record writing unit & integration tests. Strong problem-solving skills, with the ability to meet deadlines in collaborative environments. Nice-to-Have Skills Experience with Snowflake (cloud data warehousing). GraphQL API development experience. This is an urgent vacancy. If you are interested then please apply directly to the ad Randstad Technologies is acting as an Employment Business in relation to this vacancy.

Backend Developer - Java/Spring Boot - Warwickshire - Permanent Hybrid working - this opportunity requires 2-3 days/week on site in Warwickshire Competitive salary offering Backend Developer required for a leading client based in Warwickshire. You will come on board to design, build and optimise scalable services and APIs, relating to AI-based applications, ensuring seamless integration with the Front End. Key skills & responsibilities: Develop scalable Server Side applications using Java Spring Boot and microservices architecture. Build secure, high-performance RESTful APIs to support Front End integration. Design and optimize relational databases (MySQL, PostgreSQL) for efficient data management. Resolve performance bottlenecks and enhance system scalability and reliability. Apply best practices in code quality, testing (JUnit, Mockito), and CI/CD pipelines. Collaborate with cross-functional teams to deliver cohesive, end-to-end solutions. Familiar with DevOps tools (Docker, Jenkins) and cloud platforms (AWS, GCP). Knowledgeable in application security, including OAuth2 and JWT authentication. Interested in leveraging AI and automation to improve Back End processes. Interested? Please submit your updated CV to at Crimson for immediate consideration. Not interested? Do you know someone who might be a perfect fit for this role? Refer a friend and earn £250 worth of vouchers! Crimson is acting as an employment business regarding this vacancy

JavaScript Developer Remote 48k - 55k Sellick Partnership are currently recruiting a versatile JavaScript Developer with strong experience in Vue.js on the front end and Node.js on the backend. The ideal candidate will be comfortable working across the stack to deliver high-quality, scalable web applications. Responsibilities: Develop and maintain responsive front-end applications using Vue.js. Collaborate with designers and backend engineers to create seamless user experiences. Build and optimize RESTful APIs and backend services with Node.js. Write clean, efficient, and maintainable code following best practices. Debug, test, and optimize applications for performance and scalability. Participate in code reviews and contribute to team knowledge sharing. Requirements: Proven experience with JavaScript/TypeScript Strong hands-on experience with Vue.js Backend development experience with Node.js Familiarity with REST APIs, authentication, and databases (SQL/NoSQL). Proficiency with version control (Git) and agile development workflows. Strong problem-solving skills and ability to work collaboratively. If you are open to a conversation about this opportunity, please apply. Sellick Partnership is proud to be an inclusive and accessible recruitment business and we support applications from candidates of all backgrounds and circumstances. Please note, our advertisements use years' experience, hourly rates, and salary levels purely as a guide and we assess applications based on the experience and skills evidenced on the CV. For information on how your personal details may be used by Sellick Partnership, please review our data processing notice on our website.

(SalesForce) Commerce cloud architecture Skilled with javascript, Node.js Strong HTML, CSS Salesforce Commerce Cloud Developer (SFCC) Location: Uxbridge, London (Hybrid) Salary: £70,000 - £75,000We're working with a luxury client to find a talented Salesforce Commerce Cloud Developer to join their e-commerce team. This is your chance to work on world-class e-commerce solutions in a collaborative, fast-paced environment. What you'll do: Develop and enhance features on Salesforce Commerce Cloud (SFCC). Integrate third-party services like payment gateways, CMS, and marketing tools. Optimise code for performance, scalability, and security. Collaborate with UX/UI designers, product owners, and other developers in an agile team. Mentor junior developers and contribute to best practices. What we're looking for: 5+ years in e-commerce development (frontend & backend). Strong skills in JavaScript (ES6+), Node.js, HTML/CSS, and responsive design. Experience with SFCC, SFRA, REST APIs, Git, and CI/CD pipelines. Problem solver, team player, and agile working experience. Perks: Hybrid working - 3 days in Uxbridge office. Competitive salary: £70,000 - £75,000. 25 days holiday (which increases with service) Employee discounts Work with a prestigious luxury brand in a supportive environment.

Full Stack Integration Developer - Azure, .NET, NextJS Full Stack Integration Developer - Azure, .NET, NextJS - Active SC Clearance is ESSENTIAL A leading technical consultancy is seeking a Full Stack Integration Developer for an Outside IR35 contract. This hybrid role (London-based) offers and requires SC Clearance. You'll play a key role in a large-scale digitisation program, developing and integrating modern web applications within an Azure ecosystem. While primarily hands-on, you'll also contribute to architectural design and strategy. Key Responsibilities: Application Development: Build and maintain scalable web applications using .NET (C#, ASP.NET Core) and Azure Functions. Front End Development: Develop modern UIs using NextJS and other JavaScript frameworks. Integration & Backend: Work with Azure Service Bus, Event Grid, and Static Web Apps. Design and optimize SQL Server databases, stored procedures, and APIs. DevOps & Infrastructure: Create and manage CI/CD pipelines using Azure DevOps, GitHub Actions, or Jenkins. Architecture Support: Contribute to high- and low-level design documentation and advise on integration strategy. Skills & Experience: Strong experience with .NET, Azure Functions, Azure SQL, Service Bus, and Event Grid. Proficiency in NextJS or similar JavaScript frameworks. Solid understanding of CI/CD and infrastructure automation. Experience integrating third-party APIs and services. Ability to contribute to architectural decisions and communicate effectively with stakeholders. Requirements: Active SC Clearance. Experience working in government or GDS environments

Senior Full Stack Developer Tech : AWS, NodeJS, TypeScript, JavaScript, ReactJS Why? scaling FinTech, revolutionising the industry Location : Hybrid - 1-2 days in the office (Central London) Our Client A new UK-based financial services provider is launching credit card, personal loans and insurance offerings aimed at delivering fair, flexible, and user-friendly financial products to consumers. The organisation is committed to empowering individuals by enhancing their understanding and control of personal finance through clarity, intelligence, and technology. Senior Full Stack Developer - Responsibilities Design, develop, and maintain advanced applications. Collaborate with cross-functional teams to define, design, and ship new features. Guide and develop the skills of junior engineers. Optimize components for maximum performance across a vast array of web- capable devices and browsers. Maintain code and write automated tests to ensure the product is of the highest quality. Lead the development team in implementing methodologies that enhance project quality and speed. Troubleshoot and debug to optimize performance. Provide code reviews, feedback, and mentorship to junior developers. Stay up-to-date with new technology trends, applications, and protocols Senior Full Stack Developer - Experience Required Proven experience as a Senior Full Stack Developer or similar role with a strong portfolio of projects. Expertise in Node.js and AWS Lambda for serverless backend services. Proficiency in React with Next.js for frontend development. Proficiency in TypeScript and experience with infrastructure as code using Terraform. Understanding of RESTful APIs and web application architecture. Experience in a start-up environment. Bachelor's or Master's degree in Computer Science, Engineering, or a related field, or equivalent experience. Familiarity with RESTful APIs and mobile libraries for networking. Strong proficiency in JavaScript, including DOM manipulation and the JavaScript object model. Experience with automated testing suites, like Jest or Mocha. Excellent problem-solving skills and the ability to think algorithmically. Experience with cloud message APIs and usage of push notifications. Knowledge of CI/CD pipelines, code signing, and deployment (App Store, Google Play). Understanding of secure coding practices. Excellent written and verbal communication skills For more information, contact Katie at Matched Group. Senior Full Stack Developer / Senior Full Stack Engineer / Full Stack Developer / Full Stack Engineer / Software Developer / Software Engineer / Senior Developer / Senior Engineer / Senior Software Developer / Senior Software Engineer