Platform Engineer

💻 Job title: Senior Platform Engineer

💰 Salary: £100,000 – £135,000

📍 Location: London – Hybrid

🏢 Company: B2B SaaS scale-up (4th fastest scaling start-up in Europe, 2025)

👥 Team: 40 engineers today, scaling to 80 by end of year - platform team of 4

📈 Stage: High-growth, Series-level scale-up

The company

One of Europe's fastest-scaling B2B SaaS businesses, growing from 40 to 80 engineers this year. The platform team is small, senior, and foundational - they own the infrastructure patterns, shared services, and developer experience that the entire engineering org runs on. It's a build-it-own-it culture where platform sets the guardrails and trusts other teams to ship within them.

The role

This isn't an ops or babysitting role. You're a senior engineer who's moved into platform work and wants real ownership - building the infrastructure layer that 35+ engineers depend on every day, and shaping how AI tooling gets integrated into the platform from the ground up.

🫵 What you'll be doing:

• Writing TypeScript across both application code and infrastructure as code (Pulumi - recently migrated from CDK)
• Designing, building, and maintaining AWS serverless infrastructure patterns at scale
• Owning foundational services - SSO, authentication, notifications, and core shared services
• Integrating AI tooling into the platform infrastructure - greenfield, high-ownership work
• Driving observability and DevX improvements - internal tooling, developer workflows, reducing friction across the org
• Setting the patterns and guardrails that enable engineering autonomy across the business

✅ Must-haves:

• Strong software engineering background with a shift into platform or infrastructure work
• Deep AWS knowledge - serverless in particular
• TypeScript fluency (application and IaC)
• High-growth startup experience - you know what it means to scale fast
• B2B SaaS background preferred

👍 Bonus points for:

• Experience with Pulumi or CDK
• Previous work on internal developer platforms or DevX tooling
• Exposure to AI/LLM infrastructure integration
• Observability tooling (Datadog, OpenTelemetry, etc.)