SRE: Reliability & Observability Engineer

Trainline; Greater London; Hybrid; GBP 55,000 - 63,000; Full time

Benefits offered by this job

Private healthcare

Dental insurance

Work from abroad policy

Share purchase plans (2-for-1)

EV Scheme

Extra festive time off

Family-friendly benefits

Job summary

Trainline is seeking a mid-level Site Reliability Engineer to help drive reliability across the platform. You will join the Reliability & Operations Engineering team and contribute to incident response, post-incident reviews and on-call rotations.

You'll design, build and maintain observability using metrics, logs, events and traces, while improving monitoring and alerting aligned with customer impact. A hybrid model and strong AWS/Infra as code focus shape the role.

Qualifications

• Experience of SRE concepts such as SLI, SLO and error budgets.
• Hands-on experience with observability tooling such as New Relic, Elastic (ELK Stack), Influx, Grafana or similar
• Experience working with cloud providers (preferably AWS).
• Experience troubleshooting Linux operating systems.
• Experience of scripting in at least one language (preferably Python)
• Understanding of load balancing and reverse proxy concepts, upstream config concepts, upstream health checks, worker & data flow concepts.
• Application architecture concepts (threading, queuing, readiness checks, health checks, circuit breakers, timeouts, exponential backoff, throttling).
• Experience building, maintaining and evolving time series data, retention, cardinality, deviation, moving averages and other functions.
• Experience with build, deployment & configuration management tooling such as GitHub Actions and Terraform.

Responsibilities

• Developing an understanding of system architecture, dependencies, and failure modes across the Trainline platform.
• Participating in production incident response, supporting investigation, mitigation, communication, and coordinated service restoration.
• Contributing to post-incident reviews and follow-up actions to improve reliability, scalability, and resilience.
• Taking part in the SRE on-call rotation.
• Designing, building, and maintaining observability using metrics, logs, events, and traces to support effective detection and diagnosis.
• Improving monitoring and alerting by aligning signals to business and customer impact, reducing noise and improving mean time to detection (MTTD).
• Ensuring relevant operational data is surfaced quickly and clearly during live incidents.
• Making informed tooling and technology choices using SRE principles, balancing team and business needs.
• Supporting AWS-hosted infrastructure and shared platform services using infrastructure-as-code and CI/CD tooling.
• Collaborating with product engineering teams to ensure services are operationally ready and deployed safely.
• Advising on reliability and resilience practices.
• Writing and maintaining reliable, well-structured code and scripts to support reliability and observability goals.
• Prioritising work effectively and collaborating using agile processes to deliver against team and business goals.

Skills

SRE concepts (SLI/SLO)

Observability tooling

AWS cloud experience

Linux troubleshooting

Scripting (Python)

Load balancing & reverse proxy

Application architecture concepts

Time series data & metrics

Build/deploy tooling (GitHub Actions,

Tools

New Relic

ELK Stack

Grafana

Incident.io

Docker

ECS

Terraform

GitHub Actions

AWS

Job description

Trainline is seeking a mid-level Site Reliability Engineer to help drive reliability across the platform. You will join the Reliability & Operations Engineering team and contribute to incident response, post-incident reviews and on-call rotations.

You'll design, build and maintain observability using metrics, logs, events and traces, while improving monitoring and alerting aligned with customer impact. A hybrid model and strong AWS/Infra as code focus shape the role.