Senior Kotlin Developer

HCLTech; Slough; On-site; GBP 90,000 - 135,000; Full time

Job summary

HCLTech in London is seeking two senior Kotlin/Java engineers to support and extend a cloud-hosted platform used for bookbuilding issuances across Investment Banking Capital Markets. This hands-on role emphasizes XP practices, including mob programming, test-first development, and continuous refactoring, with responsibilities spanning development, integration and production support.

You will join a high-caliber front-office team delivering a platform that handles around 1,000 global users in

Qualifications

• Experience building backend services in Kotlin.
• Expertise in XP practices including mob programming, TDD and refactoring.
• Cloud experience with GCP (GKE/Cloud Run, Cloud SQL, Memorystore, Artifact Registry, Cloud Logging, Key Management).
• CI/CD and SDLC in regulated/enterprise environments.
• Experience with production systems requiring high availability and correctness.

Responsibilities

• Work primarily in mobs, sharing design and code ownership.
• Build, test, and evolve services with emphasis on clarity and maintainability.
• Support the platform in production, using incidents to improve design and resilience.

Skills

Kotlin backend

XP practices

Mob programming

TDD

Cloud GCP

CI/CD (regulated)

Tools

GKE

Cloud Run

Cloud SQL

Memorystore

Artifact Registry

Cloud Logging

Key Management

Job description

HCLTech is a global technology company, home to 219,000+ people across 54 countries, delivering industry-leading capabilities centered on digital, engineering and cloud, powered by a broad portfolio of technology services and products. We work with clients across all major verticals, providing industry solutions for Financial Services, Manufacturing, Life Sciences and Healthcare, Technology and Services, Telecom and Media, Retail and CPG, and Public Services. Consolidated revenues as of $13+ billion.

For more information on how we process your personal data, please refer to HCLTech's Candidate Data Privacy Notice.

Role: Senior Java Kotlin Developer

HCL require two senior, experienced Kotlin engineers to support and extend a cloud-hosted platform used for bookbuilding issuances across Investment Banking Capital Markets. These roles will join a high-caliber London front-office engineering team building a new issuance platform to replace a legacy bookbuilder.

This is a hands-on engineering role with strong emphasis on Extreme Programming (XP) practices, including mob programming, test-first development, and continuous refactoring. Engineers are expected to contribute across development, integration, and production support, working closely as a team to maintain a high standard of code quality and system reliability.

Location: London

Required Skills

• Strong commercial experience building backend services in Kotlin
• Deep experience with XP practices, including:
  • Mob programming as a primary way of working
  • Test‑driven development (TDD)
  • Continuous refactoring and clean code discipline
• Cloud experience in CARE Cloud / GCP, including:
  • GKE and / or Cloud Run
  • Cloud SQL, Memorystore
  • Artifact Registry, Cloud Logging
  • Key Management
• CI/CD and SDLC experience in a regulated / enterprise environment
• Comfortable working in production systems with high availability and correctness requirements

Role Context & Responsibilities

We are building a new issuance platform to replace a legacy bookbuilder. The system is akin to a real-time trading platform, used by ~1,000 global users who add and remove orders in real time during a tight ~5-hour execution window. The platform supports issuances totalling over a trillion euros annually.

Foundational services are already in place; the focus now is on expanding into core business features such as Sales screens, hedge workflows, and allocation processes. The work is delivered incrementally, with a strong emphasis on small, testable changes, frequent feedback, and sustainable pace.

Engineers in this role:

• Work primarily in mobs, sharing ownership of design and code
• Build, test, and evolve services with a strong focus on clarity, simplicity, and maintainability
• Support the platform in production, using incidents and defects as opportunities to improve system design and resilience