Senior Backend Engineer

Popsa; City of Westminster; On-site; GBP 60,000 - 80,000; Full time

Job summary

A tech-driven company in the UK seeks a Senior Backend Engineer to manage AWS infrastructure and develop user-facing features. This role demands extensive experience with AWS, Go, and Kubernetes, while fostering collaboration across departments. Successful candidates will thrive in a fast-paced environment, contributing to innovative designs and technical solutions that impact company growth. The position provides an exciting opportunity to influence product development directly.

Qualifications

• Strong experience with AWS managed/serverless ecosystem.
• Collaborative approach with problem-solving mindset.
• Active communication across teams.
• Experience with Go and familiarity with Python or TypeScript.
• Hands-on experience with Kubernetes.
• SQL proficiency for analytical tasks.
• Knowledge of observability tools like CloudWatch, Grafana.

Responsibilities

• Develop user-facing features and maintain backend services.
• Collaborate across departments to ensure product alignment.
• Influence company growth through innovative technical design.

Skills

AWS experience

Problem-solving mindset

Clear communication

Go programming

Kubernetes

Terraform

SQL knowledge

ElasticSearch/OpenSearch

GitHub Actions

AI-based tooling

Product-focused mindset

Job description

The mission for the role:

The backend team at Popsa is responsible for the entirety of the backend, from the underlying AWS infrastructure to the microservices and code that runs on it.

As guardians of Popsa’s infrastructure the team are involved in the design and development of features from the get go; supporting with domain knowledge in API design, security and infrastructure; enabling Popsa to bring exciting features from inception to implementation.

The backend team can be considered cross discipline, operating across both the backend services and platform/devops domains — this richness keeps the workload varied and exciting.

We’re looking for a highly skilled and driven Senior Backend Engineer who can cover a wide scope of responsibilities, including user-facing feature development, infrastructure reliability and security, and development of internal services. Sitting at the heart of the company, this role will work directly with product, front-end engineering, data science, customer service and operational teams.

This is a really exciting opportunity with the potential to directly influence the company's growth, through innovative technical design and freedom to explore novel approaches.

What we are looking for

• Strong recent experience with AWS and its managed/serverless ecosystem
• A problem-solving mindset and a constructive, collaborative approach
• Clear communicator who works well across engineering and product teams
• Solid experience developing in Go, familiarity with languages such as Python or TypeScript
• would be a plus
• Hands‑on experience with Kubernetes for orchestration
• Proficient with Terraform for infrastructure configuration and provisioning
• Practical knowledge of observability tooling (CloudWatch, Grafana, Prometheus)
• Comfortable writing SQL for analytical workloads (e.g., Athena)
• Experience with ElasticSearch/OpenSearch (nice to have)
• Familiarity with GitHub Actions (nice to have)
• Interest in and active use of AI‑based tooling to support efficient engineering practices
• A technically strong, product‑focused mindset that balances engineering quality with product priorities

Some of our exciting technical challenges

• Scaling infrastructure globally to provide a low‑latency experience to our users
• Enabling real‑time design collaboration between our users
• Developing social‑graphs to help users enrich their stories

Tech Stack highlights

Core Platform

• Cloud‑hosted infrastructure running 30+ micro‑services on AWS using Kubernetes (EKS) and gRPC for interservice communication

• Serverless stack with over 250 Lambda functions for event processing
• Terraform‑managed infrastructure
• DynamoDB application database
• Prometheus, Grafana, Jaeger and Splunk for observability and alerting

User‑facing Apps

• 100% native iOS app built in Swift using the Coordinators (C‑MVVM) pattern
• 100% native Android app built in Kotlin, using JetPack Compose
• (Both mobile apps leverage native vision and machine learning frameworks to perform deep analysis on photos using our in‑house trained models)
• Modern, high‑performance Typescript web application deployed on Vercel
• Fully automated deployment workflows for Web development

Data Architecture

• S3 data lake with Athena and Apache Spark for analytical workloads
• AWS Batch for orchestration of user‑facing data‑rich features like Memory generation
• SageMaker for model training and evaluation
• Bedrock and AgentCore for agents workflows

Ops

• Linear used for work management across all teams

• Figma used for product design and front‑end prototyping
• Confluence (moving to Coda) for knowledge management

• Slack for internal comms

• Mixpanel and Growthbook for behavioural analytics and multi‑variate testing

• ChatGPT, Claude and AI‑enabled IDEs available to all team members