Principal Engineer I - Prepurchase Platform

Job Summary: JOB DESCRIPTION -Principal Engineer I, Prepurchase Platform

Location:London, UK

Division:TicketmasterUK Limited

LineManager:VP Engineering, Accounts, Identity and Pre-Purchase

Contract Terms:Full-time permanent, 40h/per week

THE TEAM The Prepurchase Platform group owns the backend services that power every fan's path to a ticket. We handle event discovery, real-time seat availability, and interactive venue experiences at massive scale, processing billions of API calls during peakon-sales. Our engineers build systems that must be fast, resilient, and available when it matters most.

THE JOB As a Principal Engineer on the Prepurchase Platform team, you will write code, build systems, and solve hard problems hands-on. This is a systems thinking role: you will reason carefully about distributed systemstradeoffs, understand why existing designs exist before proposing changes, and act on problems without waiting to be asked.

You will lead platform modernization efforts, design event-driven architectures, and deliver systems thatremainresilient during the highest-demand on-sales, working across multiple teams within the Prepurchase domain rather than within a single service area. The platforms you work on have no single correct implementation; they are a continuous series oftradeoffdecisions made under real constraints. Your value comes from understanding thosetradeoffsclearly and improving them deliberately, not from implementing solutions in a vacuum.

This is a hands-on technical role with no direct reports. You will write production code daily, influence technical direction, and partner with teams across Ticketmaster on cross-cutting architectural decisions. Depending on team needs, you may embed deeply within a single service area or work horizontally across multipleteams,the role flexes to where the highest-impact work is.

WHAT YOU WILL BE DOING

• Identifyand act on production problems without being prompted. A single 500 error reaching a fan is a problem, not a data point; treat it accordingly and act with urgency regardless of volume.

• Build end-to-end, high-availability systems that handle extreme traffic spikes during high-demand on-sales without degradation.

• Lead platform modernization initiatives - migrating legacy services to cloud-native, microservice-based architectures.

• Design and implement streaming and event-driven solutions using Kafka/gRPC, enabling real-time data flow across services.

• Embed deeply in a specific service area whenneeded, orwork horizontally across teams to solve cross-cutting problems.

• Champion resilience patterns: circuit breakers, graceful degradation, bulkheads, and auto-scaling strategies.

• Collaborate with the Enterprise Architecture team on architectural decisions and evolve engineering standards across the Prepurchase domain.

• Partner with product, security, and SRE teams to align technical decisions with business priorities.

• Drive observability improvements - ensuring services are instrumented for monitoring, alerting, and rapid incident response.

• Identifyandeliminatesingle points of failure, improving systemreliabilityand reducing on-call burden.

• Apply AI and machine learning tools to improve developer productivity, automate operational tasks, and enhance system capabilities.

• Evaluate and introducenew technologiesthat improve performance, reliability, or engineering velocity.

WHAT YOU NEED TO KNOW (or TECHNICAL SKILLS)

• Proven ability to reasonaboutdistributed systemstradeoffs- scalability, consistency, availability, latency and make defensible design decisions under real constraints. This is the core bar for this role.

• Proven experience writing production code and building high-traffic systems at scale - this is a coding role first.

• Expertisein Java (17+); and the JVM, withstrongcommand of JVM internals, garbage collection behavior, and performance tuning under load. Kotlin is a plus.

• Hands-on experience with a reactive, non-blocking framework (Vert.x, SpringWebFlux, or equivalent) and asynchronous, event-driven service design.

• Deep experience with stream processing and event-driven architecture - Kafka Streams, Apache Flink, or equivalent - including stateful streaming, topology design, and managing local state stores (e.g.RocksDB) at scale.

• Proventrack recordbuilding high-throughput, low-latency systems where tail latency, backpressure, and memory pressure are first-class design concerns.

• Strong command ofgRPC(including streaming RPC) and binary serialization formats such asFlatBuffers, Avro, orProtobuf, with schema evolution viaa registry.

• Familiarity with Data-Oriented Design (DoD) - structuring code around how data is laid out, accessed, and transformed for cache efficiency and throughput, rather than around object hierarchies.

• Experience with compact, search-oriented data structures (e.g.RoaringBitmap, succinct/bitsetrepresentations) forrepresentinglarge in-memory state efficiently. Experience with search engines (Elasticsearch,Solr) for discovery workloads is a plus.

• Strong grasp of microservice design, service mesh (Istio/Envoy), API contract evolution, and backend-for-frontend patterns, includingGraphQLAPIs and WebSocket subscriptions for real-time client delivery.

• Hands-on experience with AWS (EKS) and cloud-native operations - containerization (Docker, Kubernetes), packaging and deploy tooling (Helm,Kustomize), and infrastructure-as-code (Terraform)

• Proficiencywith caching strategies (Redis, CDN layer caching) and their application to high-traffic systems.

• Solid understanding of CI/CD pipelines (GitLab CI), andprogressive deployment strategies (blue-green, canary).

• Experience designing for high availability -mult-region active-active/active-passive architectures, failover strategies, disasterrecoveryand systems thatremainstable under adversarial load and abuse.

• Proficiencywith AI/ML tools and techniques - using LLMs, AI-assisted development, and automation to accelerate engineering workflows and improve system intelligence.

• Familiarity with observability tooling: Grafana, Splunk, Prometheus,OpenTracing, or equivalent.

• Strong understanding of security best practices - OAuth/OIDC, input validation,secretsmanagement.

• Track recordof leading technical initiatives across multiple teams without direct authority.

YOU (BEHAVIOURAL SKILLS)

• Systems Thinking: Understands distributed systems as a set oftradeoffs, not a set of correct answers.Understands that failuresemergefrom system interactions and missing feedback loops - not just broken components. Evaluates designs by asking why they exist and what constraints shaped them, not just whether they match a preferred pattern.

• Technical Vision:Anticipatesplatform challenges anddesignssystems that scale ahead of demand.

• Domain Depth: Before changing a system, invests in understanding it fully - its history, theteamsand services it interacts with, the constraints that shaped its current design, and the forces

• Ownership: Takes end-to-end responsibility for system health, performance, and reliability across the Prepurchase domain.

• Influence Without Authority: Drives architectural decisions and engineering standards through collaboration, not hierarchy.

• Communication: Explains complex technical trade-offs clearly to both engineering peers and non-technical stakeholders.

• Composure Under Pressure: Stays calm during high-severity incidents and high-demand on-sales, delivering clear resolutions.

• Continuous Improvement:Identifiesopportunities to modernize, simplify, and strengthen systems - andfollowsthrough.

LIFE AT TICKETMASTER We are proud to be a part of Live Nation Entertainment, the world's largest live entertainment company.

Our vision at Ticketmaster is to connect people around the world to the live events they love. As the world's largest ticket marketplace and the leading global provider of enterprise tools and services for the live entertainment business, we are uniquely positioned to successfully deliver on that vision.

We do it all with an intense passion for Live and an inspiring and diverse culture driven by accessible leaders, attentive managers, and enthusiastic teams. Ifyou'repassionate about live entertainment like we are, and you want to work at a company dedicated to helping millions of fans experience it, we want to hear from you.

Our work is guided by our values:

Reliability- We understand that fans and clients rely on us to power their live event experiences, and we rely on each other to make it happen.

Teamwork- We believe individual achievement pales in comparison to the level of success that can be achieved by a team

Integrity- We are committed to the highest moral and ethical standards on behalf of the countless partners and stakeholders werepresent

Belonging- We are committed to building a culture in which all people can be their authentic selves, have an equal voice and opportunities to thrive

EQUAL OPPORTUNITIES We are passionate and committed to our people and go beyond the rhetoric of diversity and inclusion . click apply for full job details