Lead Developer (Enterprise Modernisation, Platform and Cloud)

Most modernization efforts fail because they focus solely on the technology. In the Enterprise Modernisation, Platform and Cloud Service Line , we do things differently. We solve some of the hardest modernization challenges organizations face—from legacy and mainframe transformation to cloud native development, platform engineering, and developer experience. We don’t just upgrade technology; we evolve architectures, processes, and engineering cultures to help organizations become evergreen and ready for inevitable change. We combine strategic advisory thinking with deep delivery expertise to transform large, complex, and business-critical technology estates (including monoliths, mainframes, and fragmented cloud environments) into scalable, continuous-improvement landscapes. We help clients move away from fragile, hard-to-change systems. By prioritizing measurable business value and delivering in shorter cycles than our competitors, we ensure our clients can adopt the state-of-the-art quickly, improve how their teams build and run software, and drive long-term, sustained value. As a Lead Developer, you will act as the primary point of contact for our clients, ensuring that teams are successful in their delivery. In this role, you will bring a strategic mindset to projects and spend time collaborating and negotiating with clients to bring a technical vision to life. Having a balance of high-level and tactical mindsets is a must, as you will spend time both with clients and your teammates. At Thoughtworks , we believe in going above and beyond the standard and are committed to delivering best-in-class solutions that exceed our clients' expectations. Our standard engineering and delivery practices reflect our commitment to quality, and our team is always looking to innovate and improve. As a leader, you will guide and coach your teams in their implementation and application. Job responsibilities You will champion and adopt best practices like writing clean and reusable code using TDD , pair programming and design patterns Champion strategic AI-first software delivery (AIFSD): You will lead in the strategic integration of AI technologies across the software development life cycle, ensuring its use is deliberate and purposeful, to maximize quality, efficiency and innovative client solutions. You will use and advocate for continuous delivery practices to deliver high-quality software as well as value to end customers as early as possible You will assess legacy systems holistically (architecture, codebase health, delivery constraints, operational risk, data dependencies and team topology) and identify pragmatic modernisation paths aligned to business outcomes. You will connect technical modernisation decisions to measurable business outcomes, helping clients prioritise the work that creates the most value earliest. You will help clients reduce legacy risk by improving testability, deployment safety, observability and recovery practices before and during migration. You will apply the latest technology thinking from our Technology Radar to solve client problems You will apply a variety of languages and tools to your work and continue to code alongside Developers; you will not be post-technical in this role You will efficiently utilize and champion DevSecOps tools and practices to build and deploy software, advocating devops culture and shifting security left in development You will cultivate Thoughtworker growth and development by encouraging feedback and fostering an inclusive, supportive team culture Job qualifications Technical Skills You are well-versed in two or more languages (Java, Kotlin, JavaScript, TypeScript, Ruby, C#, etc.) and are comfortable with the latest Object-Oriented technology. Understanding of modernisation patterns and the judgment to apply them pragmatically in complex legacy environments. Ability to evaluate when to refactor, replatform, re-architect or replace, and to explain those trade-offs clearly to both t…