Senior Software Architect & Tech Lead

SMG; City of Westminster; Hybrid; GBP 85,000 - 120,000; Full time

Benefits offered by this job

10% discretionary bonus

Wellbeing fund

Headspace subscription

Uni Fund for learning

Wellbeing Days off

Summer conference

4pm finishes every Friday

Flexible and hybrid working

Job summary

SMG is seeking a Senior Software Engineer to anchor the Plan-Apps squad in London. The role is hands-on and focused on architectural direction, setting standards and designing new features for a data-centric, service-oriented stack.

You will own feature design end-to-end, mentor engineers, and drive cloud infrastructure, CI/CD pipelines, and API-first architectures while balancing cost, security, and performance.

Qualifications

• Significant hands on experience delivering at senior level, with a track record of owning features from design through to production.
• Deep knowledge of JavaScript and TypeScript, including strong command of React and Node.js.
• Demonstrable experience defining technical architecture for non-trivial features, and articulating the trade-offs behind those decisions.
• Evidence of raising the standard of engineers around you: mentoring, coaching, review culture, or leading a project team.
• Practical experience with NoSQL databases, ideally MongoDB, and comfort working with relational data.
• Strong cloud infrastructure experience: designing, deploying and optimising cloud infrastructure.
• Experience with containers, CI/CD pipelines and Infrastructure as Code such as Terraform.
• Strong grasp of security and performance considerations in production web applications.
• Excellent communication skills, including the ability to explain technical decisions to non-technical stakeholders.
• Experience line managing engineers, or clear readiness to take it on.
• Experience decomposing a monolith into services, or defining service boundaries in a distributed system.
• Exposure to data warehousing or analytical data modelling alongside transactional systems.
• Experience designing API-first architectures, webhook integrations or third party platform integrations.
• Familiarity with observability and SRE practice: monitoring, logging, tracing and incident response.

Responsibilities

• Design and stand up new services that solve real user problems, setting their boundaries, interfaces and data ownership so they fit the wider Plan-Apps estate.
• Define the code architecture for new features within the squad's domain, and take end to end ownership from design through implementation to production deployment.
• Make and justify technical decisions with an understanding of their longer term cost.
• Break down ambiguous or poorly specified problems into deliverable work for the squad.
• Contribute to shared libraries and reusable components, flagging where duplication is emerging.
• Act as a point of contact and learning for less experienced engineers; coach and guide them through review, pairing and day to day support.
• Provide technical leadership on projects, coordinating engineering effort across the squad.
• Contribute to hiring through technical interviews and assessment.
• Maintain and optimise our cloud infrastructure with attention to reliability, security, performance and cost.
• Build and improve CI/CD pipelines and automated testing within the deployment patterns
• Identify and drive improvements to code quality, developer experience and performance, making the commercial case as well as the technical.
• Provide technical input into requirements and tickets during refinement, surfacing feasibility, effort and risk.

Skills

JavaScript

TypeScript

React

Node.js

NoSQL

MongoDB

Cloud infrastructure

CI/CD

Terraform

Observability

API design

Security

Leadership

Tools

Terraform

CI/CD tooling

Observability tools

Job description

SMG is seeking a Senior Software Engineer to anchor the Plan-Apps squad in London. The role is hands-on and focused on architectural direction, setting standards and designing new features for a data-centric, service-oriented stack.

You will own feature design end-to-end, mentor engineers, and drive cloud infrastructure, CI/CD pipelines, and API-first architectures while balancing cost, security, and performance.