Sr. Platform Engineer

About Onedome

We're a UK fintech building high-throughput digital infrastructure for the mortgage and property space. Recently acquired Trussle. We're taking our platform to the next level: fully automated, self-healing, observable, and built to handle real traffic spikes (we have a TV launch coming up).

The role

You'll be our senior platform engineer. Not a traditional ops role. You'll treat infrastructure as a product, build the internal developer platform our engineers deploy through, and bring SRE discipline into the application tier when it's needed.

You won't have a platform team to lean on. You'll be building that capability. We know exactly what we need.

What you'll do

Own 5 AWS accounts across the organisation (QA, Prod, Infra, plus two others)

Architect and maintain infrastructure as code with Terraform. Replace the click-ops that's still around

Stand up CI/CD pipelines engineers actually want to use. Blue/green and canary where it makes sense

Run releases reliably and reduce key-person risk on the deploy process

Set up monitoring, alerting, and incident response so we catch issues before customers do. Define SLIs and SLOs that map to real user journeys

Lead incident response as the primary infra responder. Run blameless post-mortems

Patch and harden the platform. We're a fintech, this matters. IAM least privilege, secrets management, vulnerability scanning, MFA enforcement

Lead infrastructure work for the TV launch: traffic spikes, autoscaling, capacity planning, runbooks

Partner with backend engineers when production issues cross into the app tier. JVM tuning, connection pools, async patterns, memory leaks

Architect multi-region DR. Drive the platform toward self-healing

Optimise cost across DynamoDB, Lambda, and the wider AWS footprint

Set architectural guardrails with tech leads and SWEs. Mentor engineers as the platform capability grows

You must have

6+ years hands-on AWS in production (VPC, IAM, EC2/ECS/EKS, Lambda, S3, CloudFront, Route53, RDS, DynamoDB, SQS)

Production Terraform (Terragrunt a plus). Multi-environment state management

Production Kubernetes and Docker. EKS specifically

Strong CI/CD experience: GitHub Actions, GitLab, Jenkins, or ArgoCD. GitOps practices

Strong infrastructure security: IAM least privilege, secrets, patching, vulnerability scanning, MFA enforcement

Observability from scratch: CloudWatch, Datadog, Grafana, Prometheus, OpenTelemetry, or ELK

Solid backend competency in Java (Spring Boot), Python, or Node. Understanding of JVM, concurrency, async systems

Comfort being the senior infrastructure person. Self-directed, opinionated, disciplined about documentation

B2/C1 Level English

Nice to have

Fintech or other regulated industry experience

DynamoDB at scale (we run many tables with PITR and S3 exports, Lambda-driven daily incrementals)

AWS cost optimisation track record

Past experience as a first infrastructure hire at a small team

Building internal developer platforms or self-service tooling

AWS DevOps Pro, Solutions Architect Pro, or CKA

Service mesh experience (Istio, Linkerd) and DevSecOps practices

Firebase or GCP exposure (we have a small footprint there)

What you won't get from us

A platform team to lean on. You'll be building that capability

Click-ops everywhere. You'll be replacing what exists with IaC

Ambiguity about the work. We know exactly what we need

Working setup

UK working hours.

Fully remote across the EU

Tooling: Microsoft 365, Teams, Planner, Nuclino, GitHub

aws-vault with MFA enforcement on all accounts

Sustainable on-call rotation

Salary: $4,000 – $5,000 / month

Originally posted on Himalayas