Lead Engineer (Node.js and AWS)

Senior / Lead Software Engineer (Backend-Focused, Full-Stack)

Location: London (Hybrid – onsite a few days per month)

Stage: Seed to Series A

Company Type: Early-stage B2B SaaS / Intelligence Platform

About the Company:

Our client is an early-stage technology company building a next-generation intelligence platform that helps organisations gain real-time visibility into external risks and signals across their ecosystem.

The platform aggregates, enriches and analyses large volumes of external data to support decision-making for security, risk, procurement, finance and resilience teams. The focus is on speed, clarity and scale, turning complex data into actionable insight.

The company has successfully closed its seed round and is now entering a critical growth phase, expanding both its engineering team and platform capabilities in preparation for Series A.

The Role:

This is a foundational engineering hire . As a Senior / Lead Software Engineer, you’ll play a key role in designing, building and scaling core systems while helping establish strong engineering foundations.

You’ll work closely with engineering leadership to shape architecture, improve reliability, and influence how the team and platform evolve. While the role spans the full stack, it has a strong emphasis on backend services, data processing and cloud infrastructure .

This role is ideal for someone who enjoys building scalable systems from the ground up and wants real ownership and influence in an early-stage environment.

What You’ll Do:

Backend & Platform Development:

• Design and build scalable backend services using TypeScript/Node.js and Python
• Develop and maintain APIs and integrations with internal and external data sources
• Build data ingestion and processing pipelines handling high-volume external signals
• Implement strong observability: logging, monitoring, alerting and error handling
• Write clean, well-tested, maintainable code with clear documentation

Cloud & Infrastructure:

• Own and evolve cloud infrastructure on AWS (ECS, Lambda, RDS, S3, SQS, EventBridge, etc.)
• Design systems with scalability, reliability and cost efficiency in mind
• Manage infrastructure using Terraform (infrastructure as code)
• Build and maintain CI/CD pipelines for reliable deployments
• Apply security best practices across application and infrastructure layers
• Troubleshoot, monitor and optimise production systems

Architecture & Technical Leadership:

• Contribute to long-term architectural decisions and platform direction
• Identify technical debt and propose pragmatic solutions
• Evaluate tools and technologies where they add real value
• Document systems, decisions and patterns to support team growth
• Participate in incident response and continuous improvement efforts

Team & Collaboration:

• Work closely with engineering leadership on priorities and planning
• Support hiring, onboarding and mentoring of new engineers
• Collaborate with Product and stakeholders on requirements and trade-offs
• Communicate clearly, proactively and constructively across teams
• Help foster a culture of quality, learning and ownership

Tech Stack (Current & Evolving):

Backend:

• Node.js, TypeScript, Fastify
• Python (data processing & automation)
• PostgreSQL, Redis
• Event-driven / microservices architecture
• Workflow automation tools
• LLM-powered enrichment pipelines

Infrastructure:

• AWS (ECS, Lambda, RDS, S3, CloudFront, SQS, EventBridge, IAM, VPC)
• Terraform
• GitHub Actions (CI/CD)
• Monitoring & observability tooling

Frontend (contextual involvement):

• React, TypeScript, Next.js, Vite

Nice to Have:

• Graph databases / relationship modelling
• .NET exposure for specific integrations
• Cybersecurity, risk or intelligence-platform experience
• Compliance or regulatory-driven environments

What Success Looks Like (First 12 Months):

• Core backend services are more scalable, reliable and observable
• Clear architectural patterns established for the wider team
• Ownership of at least one major platform capability end-to-end
• Infrastructure costs are visible, understood and optimised
• Strong working relationships across engineering and product
• Active contribution to hiring and mentoring
• Recognised as a trusted technical voice within the team

Ideal Background:

• 5+ years of backend engineering experience
• Strong hands-on experience with TypeScript/Node.js and Python
• Proven experience building and operating production systems on AWS
• Experience designing systems with scalability in mind
• Comfortable working across the stack when required
• Startup or scale-up experience preferred
• Infrastructure-as-code experience (Terraform strongly preferred)
• Clear communicator who can explain technical decisions effectively

Bonus:

• Data pipelines / high-volume ingestion experience
• Graph or network-based data modelling
• Domain exposure to security, risk or intelligence platforms
• Experience mentoring or helping grow engineering teams

What the Client Is Looking For:

• Builders who care about doing things properly
• Engineers who think beyond “it works” and plan for growth
• People who enjoy helping others grow and sharing knowledge
• Curious, humble and continuously learning professionals
• Clear communicators who are comfortable with ownership

Why Join:

• Foundational impact: Shape the platform and engineering culture from an early stage
• Real ownership: Your decisions and contributions matter
• Growth journey: Be part of the scale-up from seed to Series A and beyond
• Challenging domain: Work on complex, meaningful problems
• Competitive package: Salary, equity, flexibility and benefits aligned with seniority